What is this droplet of liquid that comes out of a mosquito?

What is this droplet of liquid that comes out of a mosquito?

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I have been looking at pictures of different species of mosquito and several times I came across pictures where the mosquito seems to be secreting some kind of fluid.

In the pictures one can clearly see that the mosquito both secretes transparent fluid and blood.

  • What kind of fluid is the transparent stuff? Could it be plasma from the host's blood?
  • Why does the mosquito do it?

Short answer
Excretion of blood and urine may prevent overheating by reducing body temperature through evaporative coolong (akin to perspiration). Excretion of blood and urine also concentrates the ingested blood.

Female Anopheles mosquitoes seek blood for nutrients necessary to egg production. The cold-blooded insects may excrete some freshly ingested blood as a way to avoid overheating when consuming blood as warm as 104 degrees Fahrenheit (40°C). It is thought that excretion of a droplet of fluid aids in evaporative cooling, similar to perspiration in humans, to reduce the animal's temperature. The excretion of urine may serve a similar purpose, namely avoiding overheating during blood ingestion. By keeping the urine or blood droplet attached to the abdomen, excessive heat can be eliminated (Lahonde & Lazarri, 2012).

In the malaria mosquito (Anopheles stephens) the excretion of fluids has been investigated in detail. Females ingest blood meals that are equivalent to more than twice their unfed body mass. Engorged animals can fly only with great difficulty, making them more prone to predation. The blood meal serves primarily as a source of protein for egg development, but it also contains considerable amounts of unwanted salts and water that threaten haemolymph homeostasis. To counter this, a rapid natriuresis and diuresis commences even before the blood meal is completed, and ∼40% of the imbibed plasma volume and salt are voided within 1-2 h of feeding (Coast et al., 2005).

- Coast et al. Exp Biol (2005); 208: 3281-91
- Lahonde & Lazarri, Curr Biol (2012); 22: 40-5

Further readings
- Do mosquitoes urinate on you when they bite you?

The Differences Between Thermal and ULV Foggers

Insect foggers can generally be categorized into two large groups:

You may have come across one or both of these terms when browsing for pest control products.

While the purpose of both types of fogger is the same, they use different fogging techniques and require different types of fogging liquids. And when talking about cold foggers you can make the decision to buy a handheld fogger or more practical backpack fogger.


Thermal foggers are so named because they heat up a coil within a metal tube, causing the liquid insecticide solution to vaporize. They then propel this vapor (composed of hundreds of tiny droplets) out in a visible cloud. The heat for thermal foggers comes from either propane or electricity.

As mentioned, there are two types of thermal foggers:

  1. Gas thermal foggers – require a gas cylinder (usually propane) to be mounted to the fogger.
  2. Electric thermal foggers – use electricity or batteries.

Gas and battery-powered foggers are cordless, fully portable, and can be used anywhere, while some electric foggers are subject to the length of their cable or an extension cord.

Propane foggers are more expensive due to the consumption of gas instead of electricity.

ULV (ultra-low volume) foggers, also called cold foggers, don’t use heat. Instead, they produce fog using pressure in one of two ways:

  1. Either the insecticide solution is pumped through a high-pressure nozzle
  2. or the solution is slowly sent through a vortex of high-speed air. The pressure breaks up the liquid into tiny droplets, which then spray out as an invisible fog.

The motors are typically powered by either electricity or batteries but some models use gasoline. Operators can adjust the size of the droplets produced by ULV foggers, allowing for different uses. The lack of heat (and thus fire risk) makes ULV foggers safer for indoor use.

Particle Sizes

Droplet sizes vary by model.

  • Thermal foggers generally produce smaller droplets, with a minimum diameter of 1 micrometer.
  • ULV foggers typically produce slightly larger droplets, with a minimum diameter of 2 micrometers.

Because thermal foggers produce such small droplets and visible fog, they are ideal for outdoor applications. Smaller droplets hang in the air longer, increasing the likelihood that they will contact a flying insect.

Furthermore, tiny droplets penetrate dense foliage better than larger droplets. Visible fog is easier to monitor and control than invisible fog, allowing for greater efficiency.

However, because the droplet diameter cannot be controlled in thermal foggers, their size can vary dramatically, which somewhat reduces their efficacy.

ULV foggers, on the other hand, produce more precisely sized droplets that can be varied by the operator. This provides versatility not available in thermal foggers.

And, as their name suggests, ultra-low volume foggers use less insecticide, making them more economical and slightly more environmentally friendly.

Thermal and ULV foggers have similar uses in many aspects. Both can spray either a water or oil-based fogging solution

In addition to pest management, both can be used to disinfect rooms and control odors, mold, and fungus indoors and outdoors.

However, in some situations, one or the other type may be better suited.

Thermal foggers generate smaller droplets in a visible fog, making them ideal for such applications as:

  • Insect control (including mosquitoes): For control of insect vectors (insects that transmit diseases/viruses to humans), the optimal droplet size is 10-15 micrometers, well within the range produced by thermal foggers. As mentioned, smaller droplets remain suspended longer and penetrate dense vegetation better than larger droplets.
  • Directed outdoor applications: The visibility of the fog produced by thermal foggers allows for operators to monitor and control the direction of the spray.
  • Small, hidden areas: The small droplets produced by thermal foggers are ideal for depositing insecticide in cracks and crevices in floors, ceilings, and walls, as well as dense thickets and other foliage.

ULV foggers, on the other hand, don’t heat up, reducing the risk of fire. Furthermore, the invisible fog makes them better suited for neighborhoods and military encampments, where visible “smoke” could cause alarm. They are also quieter than thermal foggers.

  • Indoors: As mentioned above, ULV foggers do not heat up and can be used inside.
  • Disinfecting and odor control: ULV foggers can be used to disinfect indoor spaces and can be operated remotely.
  • Mold and fungal control: Mold control solutions and fungicides can be applied using ULV foggers indoors as well as on crops (in greenhouses or gardens).



Dear Karen,
Can I use outdoor cold fogging solution ( to be mixed in water) in a sprayer(as fogging machines are very expensive) What results will I get.


Hi Kalpana.
You can use cold fogging solution in a sprayer, however there are few disadvantages when compared with cold ULV fogger which you need to be aware of:
1) A regular sprayer cannot atomize fogging solution in such small particles as ULV fogger so it won’t cover as much area and won’t be able to penetrate smaller gaps and holes because of the larger particle size.
2) Most cold ULV foggers have pretty powerful electric motors so they can output solution in much greater distances than hand sprayers, but this won’t be a problem if you need to fog a small area.
Other than that, you can use a cold fogging solution in a sprayer.

Let me know if you have any other questions.
Regards, Karen.


Dear Karen
Thanks for the prompt reply and very helpful answer.Please let me know what is the difference in solution /contents used for outdoor cold fogging vs indoor cold fogging.


Hi Kalpana.
Glad that my previous answer was useful to you!
As for your question, I think that the main difference between outdoor and indoors cold fogging solutions is their content. If you want to fog an indoors space chances are that it will be your home or a place where you spend a lot of time so you should look for a solution that is more natural and isn’t as potent, because it will be safer for you as well as it will be easier to air out the space after fogging. A good option is Pyrethin based solution diluted with water.
But for an outdoors space a solution you can either simply use a Pyrethrin based solution, because it is natural enough so that you can spend time in the sprayed area soon after fogging but it will still kill all of the mosquitoes, or really any other solution that is meant for cold fogging in outdoors environment, because outside you don’t have to worry too much about residue or airing out the space.
Hope this helps!


Thanks for the info! Really very helpful.

I am looking to use a fogger to help control or get rid of bird mites in my home. I am looking at Kleen Green Natural Enzyme as it is not toxic. Spraying the entire house using a hand spray bottle is not practical. However, the Kleen Green is only effective while wet and leaves no residual effect. Would it come out of the fogger wet enough to help? I would appreciate some advise in this. Would using a humidifier be a better solution? I would rather use a fogger if this would work. Thank you.


Hi Jane,
I agree that spraying the whole house with the Kleen Green Natural Enzyme using a hand sprayer bottle isn’t practical, however, since the label says that the product needs to be applied wet and then wiped off, I am not sure that using a fogger would be your best course of action. I would suggest getting a manual pump sprayer, like this one for example, that will still distribute the product wet, but at higher rates than regular spray bottles, so it will be much easier for you to spray your whole house with the product in small amount of time.

that’s really helpful


I’ve been researching thermal foggers for use around my home this spring and summer for mosquitos, biting gnats and biting flies. I live on about 30 acres surrounded partially by a swamp. I anticipate fogging about a 5 to 10 acre area with the fogger on the back of a utility vehicle. I will be fogging around my home and a three acre pond that I occasionally fish and we eat the fish. So I need something efficient and environmentally safe. I am looking at several models/brands in the 2-3 thousand dollar range(hopefully 2).

Any suggestions would be helpful. Would you suggest water or oil based for the pond? What size should be adequate? Is there a particular brand/company that stands out? thanks


First of all, let’s start with the pond. In general, there is no difference whether you use a water or oil-based product when it comes to fish, what matters is the active substance used in the solution, some of these substances can be very harmful to fish while others are less. The important thing is to always read the label and gather as much information as possible of the insecticide you are going to use. In general, insecticides advertised as bio or natural are going to be less harmful to fish.

Another thing when comparing oil and water-based solutions is that oil insecticides are going to provide a longer effect because they last for much longer time on the fogged surface than water-based solutions, which is great for mosquito control. Oil-based solutions can also be applied in more windy conditions.

However, when we consider the safety of the environment, water-based products are better because they evaporate faster, which, for example, is better for fish, because they stay in contact with the chemical for much less time.

When talking about foggers there are few great options available, ones that can output water-based solutions, oil-based, or even both. You have done good research to choose thermal foggers because practically all of them can output particles at 5-30 micron size, which is the most effective for insect control. From companies, I would suggest either VectorFog or Curtis Dyna-Fog, both of these make the highest quality thermal foggers for large area fogging.

From foggers that can output oil-based solutions I can recommend this: Golden Eagle fogger by Curtis Dyna-Fog

And there are also some high-quality foggers that can output water and oil-based solutions such as the Vectorfog H200SF Portable Thermal Fogger and the Curtis DYNA-Fog Trailblazer Fogger.

What You Need to Know about Mosquito Larvae

When summer&mdashor dry season in most tropical regions in the world&mdashbegins, we are usually threatened by the attack of insects. Now, we are talking about small blood-sucking flies believed to have originally come from South Africa in about 2,700 species: mosquitoes.

Killing the tiny vampires does not solve the plague problem. Killing their offspring&mdashmosquito larvae&mdashdoes. So, how do we do that? Keep reading until the end.

1. What are mosquitoes?

Adult mosquitoes are closely related to flies&mdashespecially the midges and crane flies. They have a pair of see-through wings. If you look at the ½-inched fly way closer, they have hairs and scales on their wings. They also have long legs and proboscis&mdashfunctioned as a straw for drinking. Male mosquitoes have antennae that look like a feather.

Do not be surprised, but mosquitoes mostly feed on nectars of fruits and plants. So, why do they suck the blood of animals and humans? To answer that, first, it is only the pregnant female mosquitoes that suck our blood.

Second, they do not suck the blood of all animals, but only vertebrate ones&mdashincluding us, humans, i.e., those who have a spinal column or a backbone. Anyway, female mosquitoes suck blood to get protein for her egg development.

2. What is the life cycle of a mosquito?

Every mosquito experiences a life cycle of four different stages: from eggs to adults. Each cycle lasts in approximately one month. The following is the description of each stage.

Eggs&mdashAfter sucking blood, she lays her eggs near or on the surface of still water or moist soil. There are about 100-400 mosquito eggs usually laid and stick together to form a floating raft on the surface of the water.

Larvae&mdashMosquito eggs hatch in the water in about a week to become mosquito larvae. Mosquito larvae in water in 4 to 14 days or more, depending on the temperature, hanging upside-down under the water&rsquos surface. They breathe through a siphon tube like a snorkel.

Pupae&mdashAs soon as mosquito larvae molt for four times, they turn to pupae&mdashknown as &ldquotumblers&rdquo while still floating on the water&rsquos surface. In response to the changes of light, pupae swim in tumbling actions. They do not eat or molt anymore and stay in the water for about 1-4 days.

Adults&mdashThe pupae will come out of their casing and turn to adult mosquitoes which then will rest on the surface of the water to wait until their wings and bodies harden. As soon as they are dried, they fly away and live only for several weeks.

What Are Mosquito Dunks?

Mosquito Dunk is the brand name of a product made by Summit Chemical Company that is designed to control mosquitoes in the breeding and development phase, unlike other products such as netting and repellants that only work on adults. They also make Mosquito Bits, which have the same active ingredient as the Dunks but it is released instantly instead of a slow release over time.

The premise is simple – throw a Dunk into standing water, and it floats across the top slowly releasing an agent that kills the mosquito larvae. The brilliance of mosquito dunks is in what they release. You would think it would be a pesticide, but it’s actually a specific kind of bacteria – Bacillus thuringiensis serotype israelensis.

And if that’s as exhausting for you to read as it was for me to write it, we can both just call it by its nickname – Bti.

How Bti Kills Mosquitoes

Bti is the perfect biological control agent, which means it’s an organism that has been found to selectively kill a pest organism without harming the rest of the environment. Biological control is a huge part of modern pest management, but you don’t hear about it as much because it’s a lot slower than pesticides in most cases, so it doesn’t work for household pests. Bti is a rare exception of a biological control agent where you can see results right away!

It works by releasing toxins into the guts of larval mosquitoes. It also works on other flies like black flies and fungus gnats. And mosquitoes that die as larvae can’t grow up to become bloodsucking pests.

Well mosquitoes have a body clock just like we do.

They have a cluster of nerve cells in the mosquito nervous system which use a genetic "domino effect" to keep time. So one gene turns on, turns another one on, which turns the first one off and turns the third one on, and so on.

This changes the behaviour of the nerve cell, which in turn then changes the behaviour of the whole organism.

In fact, this is a phenomenon that was first picked up in the 1970s. I've got the paper here: Journal of Experimental Biology, "The Circadian Rhythm of Flight Activity of the Mosquito Anopheles gambiae, the Light Response Rhythm." by D.R. Jones, C.M. Cubbin, D. Marsh from Brunel University. 1972, that paper was published.

They found that mosquitoes have a body clock just like us and you can jet lag them. So, basically, it's their instinct, just like mice and other nocturnal animals use their body clock to wake them up at night to come and find food.

It's the best time for Anopheles mosquitoes to come out at night, that's when their body clock wakes them up.

But, not all mosquitoes are the same. There are some mosquito species that are active during the day but they are not active at night, and I'm thinking of a good example of this is Aedes aegypti mosquitoes. They're big, hungry mosquitoes. They spread things like dengue virus and they're a real pest because, even if you use a mosquito net, you can't protect yourself because they bite people lots of times during the day, so you find it much harder to ward off their attacks.


The oldest known mosquitoes are known from amber dating to the Late Cretaceous. Three species of Cretaceous mosquito are currently known, Burmaculex antiquus and Priscoculex burmanicus are known from Burmese amber from Myanmar, which dates to the earliest part of the Cenomanian stage of the Late Cretaceous, around 99 million years ago. [10] [11] Paleoculicis minutus, is known from Canadian amber from Alberta, Canada, which dates to the Campanian stage of the Late Cretaceous, around 79 million years ago. [12] Priscoculex burmanicus can be definitively assigned to Anophelinae, one of the two subfamilies of mosquitoes alongside Culicinae, indicating the split between these two subfamilies occurred over 99 million years ago. [11] Molecular estimates suggest that the split between the two subfamilies occurred 197.5 million years ago, during the Early Jurassic, but that major diversification did not take place until the Cretaceous. [13]

The mosquito Anopheles gambiae is currently undergoing speciation into the M(opti) and S(avanah) molecular forms. Consequently, some pesticides that work on the M form no longer work on the S form. [14] Over 3,500 species of the Culicidae have already been described. [15] They are generally divided into two subfamilies which in turn comprise some 43 genera. These figures are subject to continual change, as more species are discovered, and as DNA studies compel rearrangement of the taxonomy of the family. The two main subfamilies are the Anophelinae and Culicinae, with their genera as shown in the subsection below. [16] The distinction is of great practical importance because the two subfamilies tend to differ in their significance as vectors of different classes of diseases. Roughly speaking, arboviral diseases such as yellow fever and dengue fever tend to be transmitted by Culicine species, not necessarily in the genus Culex. Some transmit various species of avian malaria, but it is not clear that they ever transmit any form of human malaria. Some species do however transmit various forms of filariasis, much as many Simuliidae do.

Family Edit

Mosquitoes are members of a family of nematoceran flies: the Culicidae (from the Latin culex, genitive culicis, meaning "midge" or "gnat"). [17] Superficially, mosquitoes resemble crane flies (family Tipulidae) and chironomid flies (family Chironomidae).

Subfamilies Edit

Genera Edit

Mosquitoes have been classified into 112 genera, some of the more common of which appear below.

  • Aedeomyia
  • Aedes
  • Anopheles
  • Armigeres
  • Ayurakitia
  • Borachinda
  • Coquillettidia
  • Culex
  • Culiseta
  • Deinocerites
  • Eretmapodites
  • Ficalbia
  • Galindomyia
  • Haemagogus
  • Heizmannia
  • Hodgesia
  • Isostomyia
  • Johnbelkinia
  • Kimia
  • Limatus
  • Lutzia
  • Malaya
  • Mansonia
  • Maorigoeldia
  • Mimomyia
  • Onirion
  • Opifex
  • Orthopodomyia
  • Psorophora
  • Runchomyia
  • Sabethes
  • Shannoniana
  • Topomyia
  • Toxorhynchites
  • Trichoprosopon
  • Tripteroides
  • Udaya
  • Uranotaenia
  • Verrallina
  • Wyeomyia

Species Edit

Over 3,500 species of mosquitoes have thus far been described in the scientific literature. [18] [19]

As true flies, mosquitoes have one pair of wings, with distinct scales on the surface. Their wings are long and narrow, as are their long, thin legs. They have slender and dainty bodies of length typically 3–6 mm, with dark grey to black coloring. Some species harbor specific morphological patterns. When at rest they tend to hold their first pair of legs outward. They are similar in appearance to midges (Chironomidae), another ancient family of flies. Tokunagayusurika akamusi, for example, is a midge fly that look very much alike mosquitoes in that they also have slender and dainty bodies of similar colors, though larger in size. They also have only one pair of wings, but without scales on the surface. Another distinct feature to tell the two families of flies apart is the way they hold their first pair of legs - mosquitoes hold them outward, while midges hold them forward. [20]

Overview Edit

Like all flies, mosquitoes go through four stages in their life cycles: egg, larva, pupa, and adult or imago. The first three stages—egg, larva, and pupa—are largely aquatic. Each of the stages typically lasts 5 to 14 days, depending on the species and the ambient temperature, but there are important exceptions. [21] Mosquitoes living in regions where some seasons are freezing or waterless spend part of the year in diapause they delay their development, typically for months, and carry on with life only when there is enough water or warmth for their needs. For instance, Wyeomyia larvae typically get frozen into solid lumps of ice during winter and only complete their development in spring. The eggs of some species of Aedes remain unharmed in diapause if they dry out, and hatch later when they are covered by water.

Eggs hatch to become larvae, which grow until they are able to change into pupae. The adult mosquito emerges from the mature pupa as it floats at the water surface. Bloodsucking mosquitoes, depending on species, sex, and weather conditions, have potential adult lifespans ranging from as short as a week to as long as several months. Some species can overwinter as adults in diapause. [22] [23]

Breeding Edit

In most species, adult females lay their eggs in stagnant water: some lay near the water's edge while others attach their eggs to aquatic plants. Each species selects the situation of the water into which it lays its eggs and does so according to its own ecological adaptations. Some breed in lakes, some in temporary puddles. Some breed in marshes, some in salt-marshes. Among those that breed in salt water (such as Opifex fuscus), some are equally at home in fresh and salt water up to about one-third the concentration of seawater, whereas others must acclimatize themselves to the salinity. [24] Such differences are important because certain ecological preferences keep mosquitoes away from most humans, whereas other preferences bring them right into houses at night.

Some species of mosquitoes prefer to breed in phytotelmata (natural reservoirs on plants), such as rainwater accumulated in holes in tree trunks, or in the leaf-axils of bromeliads. Some specialize in the liquid in pitchers of particular species of pitcher plants, their larvae feeding on decaying insects that had drowned there or on the associated bacteria the genus Wyeomyia provides such examples — the harmless Wyeomyia smithii breeds only in the pitchers of Sarracenia purpurea. [25]

However, some of the species of mosquitoes that are adapted to breeding in phytotelmata are dangerous disease vectors. In nature, they might occupy anything from a hollow tree trunk to a cupped leaf. Such species typically take readily to breeding in artificial water containers. Such casual puddles are important breeding places for some of the most serious disease vectors, such as species of Aedes that transmit dengue and yellow fever. Some with such breeding habits are disproportionately important vectors because they are well-placed to pick up pathogens from humans and pass them on. In contrast, no matter how voracious, mosquitoes that breed and feed mainly in remote wetlands and salt marshes may well remain uninfected, and if they do happen to become infected with a relevant pathogen, might seldom encounter humans to infect, in turn.

Eggs and oviposition Edit

Mosquito habits of oviposition, the ways in which they lay their eggs, vary considerably between species, and the morphologies of the eggs vary accordingly. The simplest procedure is that followed by many species of Anopheles like many other gracile species of aquatic insects, females just fly over the water, bobbing up and down to the water surface and dropping eggs more or less singly. The bobbing behavior occurs among some other aquatic insects as well, for example mayflies and dragonflies it is sometimes called "dapping". The eggs of Anopheles species are roughly cigar-shaped and have floats down their sides. Females of many common species can lay 100–200 eggs during the course of the adult phase of their life cycles. Even with high egg and intergenerational mortality, over a period of several weeks, a single successful breeding pair can create a population of thousands.

Some other species, for example members of the genus Mansonia, lay their eggs in arrays, attached usually to the under-surfaces of waterlily pads. Their close relatives, the genus Coquillettidia, lay their eggs similarly, but not attached to plants. Instead, the eggs form layers called "rafts" that float on the water. This is a common mode of oviposition, and most species of Culex are known for the habit, which also occurs in some other genera, such as Culiseta and Uranotaenia. Anopheles eggs may on occasion cluster together on the water, too, but the clusters do not generally look much like compactly glued rafts of eggs.

In species that lay their eggs in rafts, rafts do not form adventitiously the female Culex settles carefully on still water with its hind legs crossed, and as it lays the eggs one by one, it twitches to arrange them into a head-down array that sticks together to form the raft. [26]

Aedes females generally drop their eggs singly, much as Anopheles do, but not as a rule into water. Instead, they lay their eggs on damp mud or other surfaces near the water's edge. Such an oviposition site commonly is the wall of a cavity such as a hollow stump or a container such as a bucket or a discarded vehicle tire. The eggs generally do not hatch until they are flooded, and they may have to withstand considerable desiccation before that happens. They are not resistant to desiccation straight after oviposition, but must develop to a suitable degree first. Once they have achieved that, however, they can enter diapause for several months if they dry out. Clutches of eggs of the majority of mosquito species hatch as soon as possible, and all the eggs in the clutch hatch at much the same time. In contrast, a batch of Aedes eggs in diapause tends to hatch irregularly over an extended period of time. This makes it much more difficult to control such species than those mosquitoes whose larvae can be killed all together as they hatch. Some Anopheles species do also behave in such a manner, though not to the same degree of sophistication. [27]

Larva Edit

The mosquito larva has a well-developed head with mouth brushes used for feeding, a large thorax with no legs, and a segmented abdomen.

Larvae breathe through spiracles located on their eighth abdominal segments, or through a siphon, so must come to the surface frequently. The larvae spend most of their time feeding on algae, bacteria, and other microbes in the surface microlayer.

Mosquito larvae have been investigated as prey of other Dipteran flies. Species such as Bezzia nobilis within the family Ceratopogonidae have been observed in experiments to prey upon mosquito larvae. [28] [29]

They dive below the surface when disturbed. Larvae swim either through propulsion with their mouth brushes, or by jerky movements of their entire bodies, giving them the common name of "wigglers" or "wrigglers".

Larvae develop through four stages, or instars, after which they metamorphose into pupae. At the end of each instar, the larvae molt, shedding their skins to allow for further growth.

Anopheles larva from southern Germany, about 8 mm long

Culex larva and pupa

Culex larvae plus one pupa

Pupa Edit

As seen in its lateral aspect, the mosquito pupa is comma-shaped. The head and thorax are merged into a cephalothorax, with the abdomen curving around underneath. The pupa can swim actively by flipping its abdomen, and it is commonly called a "tumbler" because of its swimming action. As with the larva, the pupa of most species must come to the surface frequently to breathe, which they do through a pair of respiratory trumpets on their cephalothoraxes. However, pupae do not feed during this stage typically they pass their time hanging from the surface of the water by their respiratory trumpets. If alarmed, say by a passing shadow, they nimbly swim downwards by flipping their abdomens in much the same way as the larvae do. If undisturbed, they soon float up again.

After a few days or longer, depending on the temperature and other circumstances, the dorsal surface of its cephalothorax splits, and the adult mosquito emerges. The pupa is less active than the larva because it does not feed, whereas the larva feeds constantly. [26]

Adult Edit

The period of development from egg to adult varies among species and is strongly influenced by ambient temperature. Some species of mosquitoes can develop from egg to adult in as few as five days, but a more typical period of development in tropical conditions would be some 40 days or more for most species. The variation of the body size in adult mosquitoes depends on the density of the larval population and food supply within the breeding water.

Adult mosquitoes usually mate within a few days after emerging from the pupal stage. In most species, the males form large swarms, usually around dusk, and the females fly into the swarms to mate.

Males typically live for about 5–7 days, feeding on nectar and other sources of sugar. After obtaining a full blood meal, the female will rest for a few days while the blood is digested and eggs are developed. This process depends on the temperature, but usually takes two to three days in tropical conditions. Once the eggs are fully developed, the female lays them and resumes host-seeking.

The cycle repeats itself until the female dies. While females can live longer than a month in captivity, most do not live longer than one to two weeks in nature. Their lifespans depend on temperature, humidity, and their ability to successfully obtain a blood meal while avoiding host defenses and predators.

The length of the adult is typically between 3 mm and 6 mm. The smallest known mosquitoes are around 2 mm (0.1 in), and the largest around 19 mm (0.7 in). [30] Mosquitoes typically weigh around 5 mg. All mosquitoes have slender bodies with three segments: a head, a thorax and an abdomen.

The head is specialized for receiving sensory information and for feeding. It has eyes and a pair of long, many-segmented antennae. The antennae are important for detecting host odors, as well as odors of breeding sites where females lay eggs. In all mosquito species, the antennae of the males in comparison to the females are noticeably bushier and contain auditory receptors to detect the characteristic whine of the females.

The compound eyes are distinctly separated from one another. Their larvae only possess a pit-eye ocellus. The compound eyes of adults develop in a separate region of the head. [31] New ommatidia are added in semicircular rows at the rear of the eye. During the first phase of growth, this leads to individual ommatidia being square, but later in development they become hexagonal. The hexagonal pattern will only become visible when the carapace of the stage with square eyes is molted. [31]

The head also has an elongated, forward-projecting, stinger-like proboscis used for feeding, and two sensory palps. The maxillary palps of the males are longer than their proboscises, whereas the females’ maxillary palps are much shorter. In typical bloodsucking species, the female has an elongated proboscis.

The thorax is specialized for locomotion. Three pairs of legs and a pair of wings are attached to the thorax. The insect wing is an outgrowth of the exoskeleton. The Anopheles mosquito can fly for up to four hours continuously at 1 to 2 km/h (0.6–1 mph), [32] traveling up to 12 km (7.5 mi) in a night. Males beat their wings between 450 and 600 times per second. [33]

The abdomen is specialized for food digestion and egg development the abdomen of a mosquito can hold three times its own weight in blood. [34] This segment expands considerably when a female takes a blood meal. The blood is digested over time, serving as a source of protein for the production of eggs, which gradually fill the abdomen.

Typically, both male and female mosquitoes feed on nectar, aphid honeydew, and plant juices, [35] but in many species the mouthparts of the females are adapted for piercing the skin of animal hosts and sucking their blood as ectoparasites. In many species, the female needs to obtain nutrients from a blood meal before it can produce eggs, whereas in many other species, obtaining nutrients from a blood meal enables the mosquito to lay more eggs. A mosquito has a variety of ways of finding nectar or its prey, including chemical, visual, and heat sensors. [36] [37] Both plant materials and blood are useful sources of energy in the form of sugars, and blood also supplies more concentrated nutrients, such as lipids, but the most important function of blood meals is to obtain proteins as materials for egg production. [38] [39]

Among humans, the feeding preferences of mosquitoes typically include: those with type O blood, heavy breathers, an abundance of skin bacteria, high body heat, and pregnant women. [40] [41] Individuals' attractiveness to mosquitoes also has a heritable, genetically-controlled component. [42]

When a female reproduces without such parasitic meals, it is said to practice autogenous reproduction, as in Toxorhynchites otherwise, the reproduction may be termed anautogenous, as occurs in mosquito species that serve as disease vectors, particularly Anopheles and some of the most important disease vectors in the genus Aedes. In contrast, some mosquitoes, for example, many Culex, are partially anautogenous: they do not need a blood meal for their first cycle of egg production, which they produce autogenously however, subsequent clutches of eggs are produced anautogenously, at which point their disease vectoring activity becomes operative. [43]

Female mosquitoes hunt their blood host by detecting organic substances such as carbon dioxide (CO2) and 1-octen-3-ol (mushroom alcohol, found in exhaled breath) produced from the host, and through visual recognition. Mosquitoes prefer some people over others. The preferred victim's sweat smells more attractive than others' because of the proportions of the carbon dioxide, octenol, and other compounds that make up body odor. [44] The most powerful semiochemical that triggers the keen sense of smell of Culex quinquefasciatus is nonanal. [45] Another compound identified in human blood that attracts mosquitoes is sulcatone or 6-methyl-5-hepten-2-one, especially for Aedes aegypti mosquitoes with the odor receptor gene Or4. [46] A large part of the mosquito's sense of smell, or olfactory system, is devoted to sniffing out blood sources. Of 72 types of odor receptors on its antennae, at least 27 are tuned to detect chemicals found in perspiration. [47] In Aedes, the search for a host takes place in two phases. First, the mosquito exhibits a nonspecific searching behavior until the perception of a host's stimulants, then it follows a targeted approach. [48]

Most mosquito species are crepuscular (dawn or dusk) feeders. During the heat of the day, most mosquitoes rest in a cool place and wait for the evenings, although they may still bite if disturbed. [49] Some species, such as the Asian tiger mosquito, are known to fly and feed during daytime. [50]

Prior to and during blood feeding, blood-sucking mosquitoes inject saliva into the bodies of their source(s) of blood. This saliva serves as an anticoagulant without it the female mosquito's proboscis might become clogged with blood clots. The saliva also is the main route by which mosquito physiology offers passenger pathogens access to the hosts' bloodstream. The salivary glands are a major target to most pathogens, whence they find their way into the host via the saliva.

A mosquito bite often leaves an itchy weal, a raised bump, on the victim's skin, which is caused by histamines trying to fight off the protein left by the attacking insect. [51]

Mosquitoes of the genus Toxorhynchites never drink blood. [52] This genus includes the largest extant mosquitoes, the larvae of which prey on the larvae of other mosquitoes. These mosquito eaters have been used in the past as mosquito control agents, with varying success. [53]

Hosts of blood-feeding mosquito species Edit

Many, if not all, blood-sucking species of mosquitoes are fairly selective feeders that specialise in particular host species, though they often relax their selectivity when they experience severe competition for food, defensive activity on the part of the hosts, or starvation. Some species feed selectively on monkeys, while others prefer particular kinds of birds, but they become less selective as conditions become more difficult. For example, Culiseta melanura sucks the blood of passerine birds for preference, and such birds are typically the main reservoir of the Eastern equine encephalitis virus in North America. Early in the season while mosquito numbers are low, they concentrate on passerine hosts, but as mosquito numbers rise and the birds are forced to defend themselves more vigorously, the mosquitoes become less selective of hosts. Soon the mosquitoes begin attacking mammals more readily, thereby becoming the major vector of the virus, and causing epidemics of the disease, most conspicuously in humans and horses. [54]

Even more dramatically, in most of its range in North America, the main vector for the Western equine encephalitis virus is Culex tarsalis, because it is known to feed variously on mammals, birds, reptiles, and amphibians. Even fish may be attacked by some mosquito species if they expose themselves above water level, as mudskippers do. [54] [55]

In 1969 it was reported that some species of anautogenous mosquitoes would feed on the haemolymph of caterpillars. [56] Other observations include mosquitoes feeding on cicadas [57] and mantids. [58] In 2014, it was shown that malaria-transmitting mosquitoes actively seek out some species of caterpillars and feed on their haemolymph, [59] and do so to the caterpillar's apparent physical detriment. [60]

Mouthparts Edit

Mosquito mouthparts are very specialized, particularly those of the females, which in most species are adapted to piercing skin and then sucking blood. Apart from bloodsucking, the females generally also drink assorted fluids rich in dissolved sugar, such as nectar and honeydew, to obtain the energy they need. For this, their blood-sucking mouthparts are perfectly adequate. In contrast, male mosquitoes are not bloodsuckers they only drink sugary fluids. Accordingly, their mouthparts do not require the same degree of specialization as those of females. [61]

Externally, the most obvious feeding structure of the mosquito is the proboscis. More specifically, the visible part of the proboscis is the labium, which forms the sheath enclosing the rest of the mouthparts. When the mosquito first lands on a potential host, its mouthparts are enclosed entirely in this sheath, and it will touch the tip of the labium to the skin in various places. Sometimes, it will begin to bite almost straight away, while other times, it will prod around, apparently looking for a suitable place. Occasionally, it will wander for a considerable time, and eventually fly away without biting. Presumably, this probing is a search for a place with easily accessible blood vessels, but the exact mechanism is not known. It is known that there are two taste receptors at the tip of the labium which may well play a role. [62]

The female mosquito does not insert its labium into the skin it bends back into a bow when the mosquito begins to bite. The tip of the labium remains in contact with the skin of the victim, acting as a guide for the other mouthparts. In total, there are six mouthparts besides the labium: two mandibles, two maxillae, the hypopharynx, and the labrum.

The mandibles and the maxillae are used for piercing the skin. The mandibles are pointed, while the maxillae end in flat, toothed "blades". To force these into the skin, the mosquito moves its head backwards and forwards. On one movement, the maxillae are moved as far forward as possible. On the opposite movement, the mandibles are pushed deeper into the skin by levering against the maxillae. The maxillae do not slip back because the toothed blades grip the skin.

The hypopharynx and the labrum are both hollow. Saliva with anticoagulant is pumped down the hypopharynx to prevent clotting, and blood is drawn up the labrum.

To understand the mosquito mouthparts, it is helpful to draw a comparison with an insect that chews food, such as a dragonfly. A dragonfly has two mandibles, which are used for chewing, and two maxillae, which are used to hold the food in place as it is chewed. The labium forms the floor of the dragonfly's mouth, the labrum forms the top, while the hypopharynx is inside the mouth and is used in swallowing. Conceptually, then, the mosquito's proboscis is an adaptation of the mouthparts that occur in other insects. The labium still lies beneath the other mouthparts, but also enfolds them, and it has been extended into a proboscis. The maxillae still "grip" the "food" while the mandibles "bite" it. The top of the mouth, the labrum, has developed into a channeled blade the length of the proboscis, with a cross-section like an inverted "U". Finally, the hypopharynx has extended into a tube that can deliver saliva at the end of the proboscis. Its upper surface is somewhat flattened so, when the lower part of the hypopharynx is pressed against it, the labrum forms a closed tube for conveying blood from the victim. [63]

Saliva Edit

For the mosquito to obtain a blood meal, it must circumvent the vertebrate's physiological responses. The mosquito, as with all blood-feeding arthropods, has mechanisms to effectively block the hemostasis system with their saliva, which contains a mixture of secreted proteins. Mosquito saliva acts to reduce vascular constriction, blood clotting, platelet aggregation, angiogenesis and immunity, and creates inflammation. [64] Universally, hematophagous arthropod saliva contains at least one anti-clotting, one anti-platelet, and one vasodilatory substance. Mosquito saliva also contains enzymes that aid in sugar feeding, [65] and antimicrobial agents to control bacterial growth in the sugar meal. [66] The composition of mosquito saliva is relatively simple, as it usually contains fewer than 20 dominant proteins. [67] As of the early 2000s [update] , scientists still were unable to ascribe functions to more than half of the molecules found in arthropod saliva. [67] One promising application of components of mosquito saliva is the development of anti-clotting drugs, such as clotting inhibitors and capillary dilators, that could be useful for cardiovascular disease.

It is now well recognized that feeding ticks, sandflies, and, more recently, mosquitoes, have an ability to modulate the immune response of the animals (hosts) on which they feed. [64] The presence of this activity in vector saliva is a reflection of the inherent overlapping and interconnected nature of the host hemostatic and inflammatory/immunological responses and the intrinsic need to prevent these host defenses from disrupting successful feeding. The mechanism for mosquito saliva-induced alteration of the host immune response is unclear, but the data have become increasingly convincing that such an effect occurs. Early work described a factor in saliva that directly suppresses TNF-α release, but not antigen-induced histamine secretion, from activated mast cells. [68] Experiments by Cross et al. (1994) demonstrated that the inclusion of Ae. aegypti mosquito saliva into naïve cultures led to a suppression of interleukin (IL)-2 and IFN-γ production, while the cytokines IL-4 and IL-5 are unaffected. [69] Cellular proliferation in response to IL-2 is clearly reduced by prior treatment of cells with mosquito salivary gland extract. [69] Correspondingly, activated splenocytes isolated from mice fed upon by either Ae. aegypti or Cx. pipiens mosquitoes produce markedly higher levels of IL-4 and IL-10 concurrent with suppressed IFN-γ production. [70] Unexpectedly, this shift in cytokine expression is observed in splenocytes up to 10 days after mosquito exposure, suggesting natural feeding of mosquitoes can have a profound, enduring, and systemic effect on the immune response. [70]

T cell populations are decidedly susceptible to the suppressive effect of mosquito saliva, showing increased mortality and decreased division rates. [71] Parallel work by Wasserman et al. (2004) demonstrated that T and B cell proliferation was inhibited in a dose dependent manner with concentrations as low as 1/7 of the saliva in a single mosquito. [72] Depinay et al. (2005) observed a suppression of antibody-specific T cell responses mediated by mosquito saliva and dependent on mast cells and IL-10 expression. [73]

A 2006 study suggests mosquito saliva can also decrease expression of interferon−α/β during early mosquito-borne virus infection. [74] The contribution of type I interferons (IFN) in recovery from infection with viruses has been demonstrated in vivo by the therapeutic and prophylactic effects of administration of IFN inducers or IFN itself, [75] and different research suggests mosquito saliva exacerbates West Nile virus infection, [76] as well as other mosquito-transmitted viruses. [77]

Studies in humanized mice bearing a reconstituted human immune system have suggested potential impact of mosquito saliva in humans. Work published in 2018 from the Baylor College of Medicine using such humanized mice came to several conclusions, among them being that mosquito saliva led to an increase in natural killer T cells in peripheral blood to an overall decrease in ex vivo cytokine production by peripheral blood mononuclear cells (PBMCs) changes to proportions of subsets of PBMCs changes in the prevalence of T cell subtypes across organs and changes to circulating levels of cytokines. [78]

Egg development and blood digestion Edit

Most species of mosquito require a blood meal to begin the process of egg development. Females with poor larval nutrition may need to ingest sugar or a preliminary blood meal bring ovarian follicles to their resting stage. Once the follicles have reached the resting stage, digestion of a sufficiently large blood meal triggers a hormonal cascade that leads to egg development. [62] Upon completion of feeding, the mosquito withdraws her proboscis, and as the gut fills up, the stomach lining secretes a peritrophic membrane that surrounds the blood. This membrane keeps the blood separate from anything else in the stomach. However, like certain other insects that survive on dilute, purely liquid diets, notably many of the Hemiptera, many adult mosquitoes must excrete unwanted aqueous fractions even as they feed. (See the photograph of a feeding Anopheles stephensi: Note that the excreted droplet patently is not whole blood, being far more dilute). As long as they are not disturbed, this permits mosquitoes to continue feeding until they have accumulated a full meal of nutrient solids. As a result, a mosquito replete with blood can continue to absorb sugar, even as the blood meal is slowly digested over a period of several days. [62] [79] Once blood is in the stomach, the midgut of the female synthesizes proteolytic enzymes that hydrolyze the blood proteins into free amino acids. These are used as building blocks for the synthesis of vitellogenin, which are the precursors for egg yolk protein. [62]

In the mosquito Anopheles stephensi, trypsin activity is restricted entirely to the posterior midgut lumen. No trypsin activity occurs before the blood meal, but activity increases continuously up to 30 hours after feeding, and subsequently returns to baseline levels by 60 hours. Aminopeptidase is active in the anterior and posterior midgut regions before and after feeding. In the whole midgut, activity rises from a baseline of approximately three enzyme units (EU) per midgut to a maximum of 12 EU at 30 hours after the blood meal, subsequently falling to baseline levels by 60 hours. A similar cycle of activity occurs in the posterior midgut and posterior midgut lumen, whereas aminopeptidase in the posterior midgut epithelium decreases in activity during digestion. Aminopeptidase in the anterior midgut is maintained at a constant, low level, showing no significant variation with time after feeding. Alpha-glucosidase is active in anterior and posterior midguts before and at all times after feeding. In whole midgut homogenates, alpha-glucosidase activity increases slowly up to 18 hours after the blood meal, then rises rapidly to a maximum at 30 hours after the blood meal, whereas the subsequent decline in activity is less predictable. All posterior midgut activity is restricted to the posterior midgut lumen. Depending on the time after feeding, greater than 25% of the total midgut activity of alpha-glucosidase is located in the anterior midgut. After blood meal ingestion, proteases are active only in the posterior midgut. Trypsin is the major primary hydrolytic protease and is secreted into the posterior midgut lumen without activation in the posterior midgut epithelium. Aminopeptidase activity is also luminal in the posterior midgut, but cellular aminopeptidases are required for peptide processing in both anterior and posterior midguts. Alpha-glucosidase activity is elevated in the posterior midgut after feeding in response to the blood meal, whereas activity in the anterior midgut is consistent with a nectar-processing role for this midgut region. [80]

Distribution Edit

Mosquitoes are cosmopolitan (world-wide): they are in every land region except Antarctica [62] and a few islands with polar or subpolar climates. Iceland is such an island, being essentially free of mosquitoes. [81]

The absence of mosquitoes in Iceland and similar regions is probably because of quirks of their climate, which differs in some respects from mainland regions. At the start of the uninterrupted continental winter of Greenland and the northern regions of Eurasia and America, the pupa enters diapause under the ice that covers sufficiently deep water. The imago emerges only after the ice breaks in late spring. In Iceland however, the weather is less predictable. In mid-winter it frequently warms up suddenly, causing the ice to break, but then to freeze again after a few days. By that time the mosquitoes will have emerged from their pupae, but the new freeze sets in before they can complete their life cycle. Any anautogenous adult mosquito would need a host to supply a blood meal before it could lay viable eggs it would need time to mate, mature the eggs and oviposit in suitable wetlands. These requirements would not be realistic in Iceland and in fact the absence of mosquitoes from such subpolar islands is in line with the islands' low biodiversity Iceland has fewer than 1,500 described species of insects, many of them probably accidentally introduced by human agency. In Iceland most ectoparasitic insects live in sheltered conditions or actually on mammals examples include lice, fleas and bedbugs, in whose living conditions freezing is no concern, and most of which were introduced inadvertently by humans. [81]

Some other aquatic Diptera, such as Simuliidae, do survive in Iceland, but their habits and adaptations differ from those of mosquitoes Simuliidae for example, though they, like mosquitoes, are bloodsuckers, generally inhabit stones under running water that does not readily freeze and which is totally unsuited to mosquitoes mosquitoes are generally not adapted to running water. [82] [83]

Eggs of species of mosquitoes from the temperate zones are more tolerant of cold than the eggs of species indigenous to warmer regions. [84] [85] Many even tolerate subzero temperatures. In addition, adults of some species can survive the winter by taking shelter in suitable microhabitats such as buildings or hollow trees. [86]

Pollination Edit

Several flowers are pollinated by mosquitoes, [87] including some members of the Asteraceae, Roseaceae and Orchidaceae. [88] [89] [90] [91]

Activity Edit

In warm and humid tropical regions, some mosquito species are active for the entire year, but in temperate and cold regions they hibernate or enter diapause. Arctic or subarctic mosquitoes, like some other arctic midges in families such as Simuliidae and Ceratopogonidae may be active for only a few weeks annually as melt-water pools form on the permafrost. During that time, though, they emerge in huge numbers in some regions and may take up to 300 ml of blood per day from each animal in a caribou herd. [92]

Means of dispersal Edit

Worldwide introduction of various mosquito species over large distances into regions where they are not indigenous has occurred through human agencies, primarily on sea routes, in which the eggs, larvae, and pupae inhabiting water-filled used tires and cut flowers are transported. However, apart from sea transport, mosquitoes have been effectively carried by personal vehicles, delivery trucks, trains, and aircraft. Man-made areas such as storm water retention basins, or storm drains also provide sprawling sanctuaries. Sufficient quarantine measures have proven difficult to implement. In addition, outdoor pool areas make a perfect place for them to grow.

Climate and global distribution Edit

Seasonality Edit

In order for a mosquito to transmit a disease to the host there must be favorable conditions, referred to as transmission seasonality. [93] Seasonal factors that impact the prevalence of mosquitos and mosquito-borne diseases are primarily humidity, temperature, and precipitation. A positive correlation between malaria outbreaks and these climatic variables has been demonstrated in China [94] and El Niño has been shown to impact the location and number of outbreaks of mosquito-borne diseases observed in East Africa, Latin America, Southeast Asia and India. [95] Climate change impacts each of these seasonal factors and in turn impacts the dispersal of mosquitos.

Past and future patterns Edit

Climatology and the study of mosquito-borne disease have been developed only over the past 100 years however historical records of weather patterns and distinct symptoms associated with mosquito-borne diseases can be utilized to trace the prevalence of these diseases in relation to the climate over longer time periods. [93] Further, statistical models are being created to predict the impact of climate change on vector-borne diseases using these past records, and these models can be utilized in the field of public health in order to create interventions to reduce the impact of these predicted outcomes.

Two types of models are used to predict mosquito-borne disease spread in relation to climate: correlative models and mechanistic models. Correlative models focus primarily on vector distribution, and generally function in 3 steps. First, data is collected regarding geographical location of a target mosquito species. Next, a multivariate regression model establishes the conditions under which the target species can survive. Finally, the model determines the likelihood of the mosquito species to become established in a new location based on similar living conditions. The model can further predict future distributions based on environmental emissions data. Mechanistic models tend to be broader and include the pathogens and hosts in the analysis. These models have been used to recreate past outbreaks as well as predict the potential risk of a vector-borne disease based on an areas forecasted climate. [96]

Mosquito-borne diseases are currently most prevalent in East Africa, Latin America, Southeast Asia, and India however, emergence of vector-borne diseases in Europe have recently been observed. A weighted risk analysis demonstrated associations to climate for 49% of infectious diseases in Europe including all transmission routes. One statistical model predicts by 2030, the climate of southern Great Britain will be climatically suitable for malaria transmission Plasmodium vivax for 2 months of the year. By 2080 it is predicted that the same will be true for southern Scotland. [97] [98]

Mosquitoes can act as vectors for many disease-causing viruses and parasites. Infected mosquitoes carry these organisms from person to person without exhibiting symptoms themselves. [99] Mosquito-borne diseases include:

  • Viral diseases, such as yellow fever, dengue fever, and chikungunya, transmitted mostly by Aedes aegypti. Dengue fever is the most common cause of fever in travelers returning from the Caribbean, Central America, South America, and South Central Asia. This disease is spread through the bites of infected mosquitoes and cannot be spread person to person. Severe dengue can be fatal, but with good treatment, fewer than 1% of patients die from dengue. [100] Work published in 2012 from Baylor College of Medicine suggested that for some diseases, such as dengue fever, which can be transmitted via mosquitoes and by other means, the severity of the mosquito-transmitted disease could be greater. [101]
  • The parasitic diseases collectively called malaria, caused by various species of Plasmodium, carried by female mosquitoes of the genus Anopheles. (the main cause of elephantiasis) which can be spread by a wide variety of mosquito species. [102] is a significant concern in the United States but there are no reliable statistics on worldwide cases. [103]
  • Dengue viruses are a significant health risk globally. Severe cases of dengue often require hospitalization and can be life-threatening shortly after infection. Symptoms include a high fever, aches and pains, vomiting, and a rash. Warning signs of severe dengue infection include vomiting blood, bleeding from the gums or nose, and stomach tenderness/pain. [104][105]
  • Equine encephalitis viruses, such as Eastern equine encephalitis virus, Western equine encephalitis virus, and Venezuelan equine encephalitis virus, can be spread by mosquito vectors such as Aedes taeniorhynchus. , a bacterial disease caused by Francisella tularensis, is variously transmitted, including by biting flies. Culex and Culiseta are vectors of tularemia, as well as arbovirus infections such as West Nile virus. [106] , recently notorious, though rarely deadly. It causes fever, joint pain, rashes and conjunctivitis. The most serious consequence appears when the infected person is a pregnant woman, since during pregnancy this virus can originate a birth defect called microcephaly. , a mosquito-borne disease that is characterized by fever and headaches upon initial onset of infection, arises from mosquitos who feed on birds who are infected with the illness, and can result in death. The most common vector of this disease is Culex pipiens, also known as the common house mosquito. , a parasitic roundworm infection that affects dogs and other canids. Mosquitoes transmit larvae to the definitive host through bites. Adult heart worms infest the right heart and pulmonary artery, where they can cause serious complications including congestive heart failure.

Potential transmission of HIV was originally a public health concern, but practical considerations and detailed studies of epidemiological patterns suggest that any transmission of the HIV virus by mosquitoes is at worst extremely unlikely. [107]

Various species of mosquitoes are estimated to transmit various types of disease to more than 700 million people annually in Africa, South America, Central America, Mexico, Russia, and much of Asia, with millions of resultant deaths. At least two million people annually die of these diseases, and the morbidity rates are many times higher still.

Methods used to prevent the spread of disease, or to protect individuals in areas where disease is endemic, include:

    aimed at mosquito control or eradication
  • Disease prevention, using prophylactic drugs and developing vaccines
  • Prevention of mosquito bites, with insecticides, nets, and repellents

Since most such diseases are carried by "elderly" female mosquitoes, some scientists have suggested focusing on these to avoid the evolution of resistance. [108]

Many measures have been tried for mosquito control, including the elimination of breeding places, exclusion via window screens and mosquito nets, biological control with parasites such as fungi [109] [110] and nematodes, [111] or predators such as fish, [112] [113] [114] copepods, [115] dragonfly nymphs and adults, and some species of lizard and gecko. [116] Another approach is to introduce large numbers of sterile males. [117] Genetic methods including cytoplasmic incompatibility, chromosomal translocations, sex distortion and gene replacement, solutions seen as inexpensive and not subject to vector resistance, have been explored. [118]

According to an article in Nature discussing the idea of totally eradicating mosquitoes, "Ultimately, there seem to be few things that mosquitoes do that other organisms can’t do just as well—except perhaps for one. They are lethally efficient at sucking blood from one individual and mainlining it into another, providing an ideal route for the spread of pathogenic microbes." [92] The control of disease-carrying mosquitoes may in the future be possible using gene drives. [119] [120]

Repellents Edit

Insect repellents are applied on skin and give short-term protection against mosquito bites. The chemical DEET repels some mosquitoes and other insects. [121] Some CDC-recommended repellents are picaridin, eucalyptus oil (PMD) and ethyl butylacetylaminopropionate (IR3535). [122] Others are indalone, dimethyl phthalate, dimethyl carbate, and ethyl hexanediol.

There are also electronic insect repellent devices which produce ultrasounds that were developed to keep away insects (and mosquitoes). However, no scientific research based on the EPA's as well as the many universities' studies has ever provided evidence that these devices prevent a human from being bitten by a mosquito. [123] [124]

Mosquito bites lead to a variety of mild, serious, and, rarely, life-threatening allergic reactions. These include ordinary wheal and flare reactions and mosquito bite allergies (MBA). The MBA, also termed hypersensitivity to mosquito bites (HMB), are excessive reactions to mosquito bites that are not caused by any toxin or pathogen in the saliva injected by a mosquito at the time it takes its blood-meal. Rather, they are allergic hypersensitivity reactions caused by the non-toxic allergenic proteins contained in the mosquito's saliva. [125] Studies have shown or suggest that numerous species of mosquitoes can trigger ordinary reactions as well as MBA. These include Aedes aegypti, Aedes vexans, Aedes albopictus, Anopheles sinensis, Culex pipiens, [126] Aedes communis, Anopheles stephensi, [127] Culex quinquefasciatus, Ochlerotatus triseriatus, [128] and Culex tritaeniorhynchus. [129] Furthermore, there is considerable cross-reactivity between the salivary proteins of mosquitoes in the same family and, to a lesser extent, different families. It is therefore assumed that these allergic responses may be caused by virtually any mosquito species (or other biting insect). [130]

The mosquito bite allergies are informally classified as 1) the Skeeter syndrome, i.e. severe local skin reactions sometimes associated with low-grade fever 2) systemic reactions that range from high-grade fever, lymphadenopathy, abdominal pain, and/or diarrhea to, very rarely, life-threatening symptoms of anaphylaxis and 3) severe and often systemic reactions occurring in individuals that have an Epstein-Barr virus-associated lymphoproliferative disease, Epstein-Barr virus-negative lymphoid malignancy, [131] or another predisposing condition such as Eosinophilic cellulitis or chronic lymphocytic leukemia. [126]

Mechanism Edit

Visible, irritating bites are due to an immune response from the binding of IgG and IgE antibodies to antigens in the mosquito's saliva. Some of the sensitizing antigens are common to all mosquito species, whereas others are specific to certain species. There are both immediate hypersensitivity reactions (types I and III) and delayed hypersensitivity reactions (type IV) to mosquito bites. [132] Both reactions result in itching, redness and swelling. Immediate reactions develop within a few minutes of the bite and last for a few hours. Delayed reactions take around a day to develop, and last for up to a week.

Treatment Edit

Several anti-itch medications are commercially available, including those taken orally, such as diphenhydramine, or topically applied antihistamines and, for more severe cases, corticosteroids, such as hydrocortisone and triamcinolone. Aqueous ammonia (3.6%) has also been shown to provide relief. [133]

Both topical heat [134] and cool [135] may be useful to treat mosquito bites.

Greek mythology Edit

Ancient Greek beast fables including "The Elephant and the Mosquito" and "The Bull and the Mosquito", with the general moral that the large beast does not even notice the small one, derive ultimately from Mesopotamia. [136]

Origin myths Edit

The peoples of Siberia have origin myths surrounding the mosquito. One Ostiak myth tells of a man-eating giant, Punegusse, who is killed by a hero but will not stay dead. The hero eventually burns the giant, but the ashes of the fire become mosquitos that continue to plague mankind.

Other myths from the Yakuts, Goldes (Nanai people), and Samoyed have the insect arising from the ashes or fragments of some giant creature or demon. Similar tales found in Native North American myth, with the mosquito arising from the ashes of a man-eater, suggest a common origin. The Tatars of the Altai had a similar myth, thought to be of Native North American origin, involving the fragments of the dead giant, Andalma-Muus, becoming mosquitos and other insects. [137]

Modern era Edit

Winsor McCay's 1912 film How a Mosquito Operates was one of the earliest works of animation, far ahead of its time in technical quality. It depicts a giant mosquito tormenting a sleeping man. [138]

The de Havilland Mosquito was a high-speed aircraft manufactured between 1940 and 1950, and used in many roles. [139]


In this report we demonstrate a fluid delivery method that uses small droplet surface tension to pump a desired volume through a microfluidic channel in order to achieve a number of different fluid phenomena. For example, the user may wish to flow a single fluid as fast as possible, or deliver multiple fluids in rapid succession to create specific fluidic patterns. In order to do this, the user must first have an application built around a microfluidic device. The microflluidic device does not need to be bonded, but should be made from a hydrophilic material. Therfore, the method can be utilized with almost any microfluidic device, with performance largely dictated by the geometrical constraints of the microfluidic channel. To help navigate the geometrical constraints of this method, an introduction to the relevant numerical analysis is presented first.

Analytical Methods: According to the Laplace Law and the Washburn Law [1], one can relate the flow rate within a microfluidic channel to its dimensions and the properties of the flowing liquid as seen in equation (1),

(1) where ΔP is the pressure difference between the inlet and the outlet, γ is the liquid surface tension, R is the inlet drop radius, Q is the flow rate and K is the fluidic resistance as described by equation (2),

(2) where η is the liquid viscosity, L0 is the channel length, h is the channel height, w is the channel width, λ=w/h and g(λ) =1.5 if λ Ϥ.45 or

if λ < 4.45. Substituting equation (2) into equation (1), always assuming that h<w and solving for Q, one obtains equation (3), (3)

The same analysis can be done for the velocity of the fluid inside a channel by knowing that Q=VA, where V is the fluid average velocity and A is the cross-sectional area or hw. Plugging these into equation (3) you come up with equation (4), (4)

An important mechanical concept that is frequently applied in microfluidic biology is shear stress, which relates to flow rate and velocity by equation (5), (5)

Knowing the relationship between flow rate, velocity and their physical implications as a function of channel dimensions and fluid properties is crucial in the design of a microfluidic device for a given purpose. Once a device is created, the user must then calibrate the fluid delivery system to achieve the desired flow characteristics within the device.

Steps in Setting up and Calibrating Delivery System:

Create microfluidic device via soft-lithography technique using polydimethylsiloxane (PDMS, Sylgard 184, Dow Corning) [2]. There are number JoVE articles that illustrate methods for making PDMS microfluidic devices [5]. For this demonstration, we have chosen a simple straight channel, with dimensions as follows: 2.2mm width, 10mm length and 260um height. The inlet and outlet diameters are 1.8mm and 5.1mm respectively (figure 1). Reversibly attach PDMS device to glass slide by pressing it onto a glass slide (or other suitable substrate) and squeezing out any air bubbles [5]. A reversible attachment allows the device to be re-used multiple times. The method can also be used with permanently bonded devices, but it not required.

Fill device with liquid. The hydrophobic nature of PDMS and the hydrophilic nature of glass help move a drop that is placed at the inlet, or outlet, into the channel. If the drop of liquid does not want to go into the channel by itself or if bubbles move into the channel, the user may put a drop of liquid at the inlet, or outlet, and use a pipette at the opposite end to suck the liquid through the channel. Another method of helping the liquid move into the channel is by separating the PDMS device from the glass slide and gently cleaning the PDMS device and the glass slide with ethanol. This returns to the PDMS and the glass slide their hydrophobic and hydrophilic natures, respectively, which may have been weakened with time and use.

After filling device with liquid, place a small drop on the inlet and a bigger drop on the outlet. Make sure passive pumping is happening by watching the small drop at the inlet collapse and observing fluid flow towards the outlet. Again, make sure there are no bubbles inside the channel.

Using The Lee Company’s [3] VHS micro dispensing starting kit, put together one or more valves (valve setup in figure 2) consisting of the Lee VHS M/2 24 Volt Valve, a 0.062 MINSTAC Nozzles with orifice size of 0.0100", the Lee 0.062 Minstac to Soft Tube Adapter, the Lee Spike and Hold Driver (for user control, not shown) and the Lead Wire Assembly (connecting the valve to the Spike and Hold Driver, not shown).

An easy way to hold the valves is by using the Bioscience tools miniature holders (figure 2) [4]. These provide a way to precisely aim and hold the valve at a certain position during experimentation by gluing the valve to one end of the holder and using a magnetic base (not shown) on the other side.

Make a reservoir system to be placed a few feet above the PDMS microfluidic device (in our case we used ¾ ounce syringes open to the ambient, see figure 2). The reservoir provides a pressure head to drive the nozzles, with the pressure being proportional to the height of the reservoir. Alternatively the nozzle valves can be pressurized by any number of different means (ie, compressed gas). Attach a syringe needle to the syringe. A typical syringe needle will easily attach into 1.14 mm inner diameter tubing. The 1.14 mm tubing will then easily attach into 1.58 mm (1/16”) inner diameter tubing which then itself connects to the “Soft Tube Adapter” of the valve. To prevent leakage of liquid in the 1.14 mm to 1.58 mm tubing connection, one may use PDMS as a sealant. Now that there is a line between the syringe needle and the Lee Co. valve, fill syringe reservoirs with liquid. An extra syringe and a valve may be used to help in the purging process (shown but not labeled in figure 2). Place a magnet to the side of the valve this is how these valves are purged (they are normally closed solenoid valves), and watch liquid start flowing from the reservoir through the valve and out the 0.0100’’ nozzle.

Calibrate system by choosing a valve open time (open time is the time that the valve allows fluid to pass on a per pulse basis) and frequency (number of pulses per second). Activate one valve for a chosen period (a minute or so, just remember the total run time). Weigh the fluid that was delivered from the valve. Knowing the total run time, frequency and per-pulse open time, calculate the grams per millisecond shot out from the valve. This “grams per millisecond” value will allow you to choose an open time for any desired volume the user may want to be delivered from the valve.

Example: System activated for a minute (60 seconds). The frequency was 15 Hz (15 pulses in one second). The per-pulse open time was 20 milliseconds (ms).

This means that out of the 60,000 ms in one minute, the valve was actually open for 18,000ms. Let’s assume the volume of fluid delivered weighed 5 grams. Then,

5 grams / 18000 ms = 2.78e -4 grams/ms.

In the case of water, with its density being one gram per milliliter (mL),

2.78e -4 grams/ms = 2.78e -4 mL/ms.

After calibration, the volume of a drop is dependent on the open time. For example, with an open time of 20ms, and all the parameters remaining the same as in the previous example,

(2.78e -4 mL/ms)(20 ms) = 5.56e -3 mL = 5.56 μL.

To find the open time y needed to make a drop of x microliter (μL) volume,

(x μL) / [(2.78e -4 mL/ms)(1000 μL/mL)] = y ms

8) Aim one or more nozzles to the inlet of the PDMS device (figure 3). Having calibrated the system, calculate the volume coming out of each valve, based on microfluidic device dimensions. For high speed passive pumping (to obtain maximum flow rate), calculate the inlet drop volume necessary to create an inlet drop which possesses a 90deg contact angle with inlet surface [2]. For packet creation, calculate valve frequency and open times and the valve timings necessary to activate two valves in sequence. As seen in Figure 3, the two nozzles can be pointed at the inlet. This can extended to multiple nozzles, all aimed at the channel inlet.

Representative Results:

When properly calibrated, with valve open times correctly calculated and the nozzles properly aimed at the inlet, the user should be able to see flow passively pumped (figure 4). A burst of liquid should come out of the valve and reach the inlet. As liquid reaches the inlet, there is an instant collapse of the inlet drop into the channel, towards the outlet. Liquid within the channel moves only during the collapse of an inlet drop. Complete fluid movement within the channel stops at the end of the drop collapse, providing for instantaneous fluid stop and well defined fluidic boundaries (in the case that the user is flowing multiple liquids). The duration of drop collapse depends on the inlet port radius and the volume of the inlet drop [1]. In our experimental setup and design, inlet drop collapse occurs in a matter of a few milliseconds.

Figure 1. PDMS microfluidic device with one inlet, left, and one outlet, right. Please click here to see a larger version of figure 1.

Figure 2. Reservoir system and valve setup. Please click here to see a larger version of figure 2.

Figure 3. Two valves, both aimed at a single inlet of a microfluidic device. Please click here to see a larger version of figure 3.

Figure 4. Time-step sequence (33 millisecond) of inlet drop collapse following fluid ejection from a valve. Please click here to see a larger version of figure 4.


If you’ve acquired gnat bites or expect to be getting bit during a field trip or other outdoor activity, bring some BITE RELIEF SWABS. This material will take away the itch and provide instant relief. They’re packed in handy 𔄙 dose” vials and are easy to carry afield.

Each 10 pack has enough to treat 25-50 bites and works instantly to take away the discomfort of most any insect bite.

For lingering damage to the skin, GENES SOOTHING CREAM is an all natural ointment that works wonders. It will help your skin heal and during the process take away any unpleasant discomfort. Packed in 8 oz jars, apply some in the evening before retiring to help enable your skin to both heal and feel relief.


A simple and effective method was conducted for preparing microdispersed droplets with decreased size and increased uniformity, in which phase inversion in high-phase-ratio liquid/liquid system was combined with addition of microbubbles. Five typical flow patterns were observed, including W/O, O/W/O, transition regime, O/W and G/W/O regimes. Flow regime transition was observed, according to which physical properties of systems and operating conditions for preparing single-oil-droplet-in-water emulsion were determined in different liquid/liquid and gas/liquid/liquid modes. Effects of liquid viscosities as well as interfacial tension on droplet size (DO) and its standard deviation (SD) were studied systematically and the most effective gas/liquid/liquid mode was recommended. Mathematical models were established for correlating DO in five different modes, which show relatively good agreement with experimental results. DO decreases by 42% via introducing phase inversion and further reduces to 25% by addition of microbubbles, both under the same operating conditions.

Fungus Gnats

-Wettable Sulfur (everywhere medium/root zone, vegetation, trays/pots if you want)
-Bait mix (Water, apple cider vineger, sugar, some liquid soap/other surfactant)
-Sticky traps (yellow)
-H2O2 (additionally, this "breaks down" the decaying root/plant/organic matter that the larvae feed on". it's not just to 'kill' the larvae via contact.
-BT (the active ingredient in "mosquito dunks").

You should/need to do a combo of, say, three or more of these things. And you need to do it/keep it up for 30+ days to fully disrupt their entire life cycle.

Also, manually:
-You can suck them up with a shop vac after gently shaking the plant. Or spray'em with a mix of ISO-P and water.

@DoubleAtotheRON The "pluggable" brand usb microscope on ebay is a decent one, takes high def pics and video, built in led. If you have android phone you can connect it to that with a usb-OTG cable/adapter. Valuable tool.

So you think it would be more beneficial for me not to add any organics back into the system and just continue with H2O2 and BTI?

Also, have you had to do this for 30 days before?

Well-Known Member

Each stage of the critter's life cycle has it's own "length". And each stage requires a different approach, and/or has multiple approaches that may work better or worse than the other, or benefit from using both.
I wouldn't go too overboard with the h2o2 (ie too frequently), depending on strength of mix (don't remember exactly what strength I used.)

But wettable sulfur powder is very cheap and is also something I think is a staple IPM product everyone should have some.
Yellow sticky traps aren't that expensive. Get a 60 pack of the large ones (maybe. 8"x4", can't remember) on amazon and you can cut them in half to get more out of them. They're double sided, too. Peel one side, use it, then cover it and peel the other side. Unless you hang it in "free air" where you can catch the fuckers on both sides. Definitely put some at soil/pot level, lay them on/across the lip or rim of the pot if you can, even with both sides exposed (sticky). The adults are constantly going into the medium to lay more eggs. So you get them coming and leaving.
They are attracted to the color yellow (and other bright colors I think, maybe), and they are attracted to light too. So, put the traps where grow light is hitting them (both below the canopy, like on pot rims, and hanging or placing them on walls or whatever).

Spray wettable sulfur mix (water, sulfur, and some surfactant - peppermint soap works great) on the top of the medium (maybe after water/feeding). Spray the planter drain holes. Spray the entire plant, bottom and top of leaves, and stalk -- but note when this dries it leaves a visual bit of sulfur power on the surfaces and leave - which is fine in veg. Don't confuse it for powdery mildew (which sulfur also tells to fuck off).

When you think you've defeated them, assume you haven't. They've found some bit of organic shit to eat in a nail/screw/staple hole or crack in something - or they're just hiding there waiting to rebound - so, keep new yellow traps up as an indicator of when/(if) those ones come back. Get those last 'sneaky' ones.
Probably keep spraying the top of soil and planter drain holes with sulfur mix as well.

Make sure it's just wettable sulfur, nothing else in it. It needs to be shaken and mixed well, and shook every. 30seconds or so while spraying to keep well in solution.
Something like this, not the one I use, but should be the same:
Good air movement will also help push the adult fuckers into the yellow traps.
Sometimes I would just stand still in a corner or something and watch where they'd like to land. Or tap a continuously with an object to see if/when they'd come out and where from.

Edit: I wonder how many spelling errors ^.


Well-Known Member

Each stage of the critter's life cycle has it's own "length". And each stage requires a different approach, and/or has multiple approaches that may work better or worse than the other, or benefit from using both.
I wouldn't go too overboard with the h2o2 (ie too frequently), depending on strength of mix (don't remember exactly what strength I used.)

But wettable sulfur powder is very cheap and is also something I think is a staple IPM product everyone should have some.
Yellow sticky traps aren't that expensive. Get a 60 pack of the large ones (maybe. 8"x4", can't remember) on amazon and you can cut them in half to get more out of them. They're double sided, too. Peel one side, use it, then cover it and peel the other side. Unless you hang it in "free air" where you can catch the fuckers on both sides. Definitely put some at soil/pot level, lay them on/across the lip or rim of the pot if you can, even with both sides exposed (sticky). The adults are constantly going into the medium to lay more eggs. So you get them coming and leaving.
They are attracted to the color yellow (and other bright colors I think, maybe), and they are attracted to light too. So, put the traps where grow light is hitting them (both below the canopy, like on pot rims, and hanging or placing them on walls or whatever).

Spray wettable sulfur mix (water, sulfur, and some surfactant - peppermint soap works great) on the top of the medium (maybe after water/feeding). Spray the planter drain holes. Spray the entire plant, bottom and top of leaves, and stalk -- but note when this dries it leaves a visual bit of sulfur power on the surfaces and leave - which is fine in veg. Don't confuse it for powdery mildew (which sulfur also tells to fuck off).

When you think you've defeated them, assume you haven't. They've found some bit of organic shit to eat in a nail/screw/staple hole or crack in something - or they're just hiding there waiting to rebound - so, keep new yellow traps up as an indicator of when/(if) those ones come back. Get those last 'sneaky' ones.
Probably keep spraying the top of soil and planter drain holes with sulfur mix as well.

Make sure it's just wettable sulfur, nothing else in it. It needs to be shaken and mixed well, and shook every. 30seconds or so while spraying to keep well in solution.
Something like this, not the one I use, but should be the same:
Good air movement will also help push the adult fuckers into the yellow traps.
Sometimes I would just stand still in a corner or something and watch where they'd like to land. Or tap a continuously with an object to see if/when they'd come out and where from.

Edit: I wonder how many spelling errors ^.

or you can increase the soil biology to eat the gnat larvae before it grows wings and flies away. And you do that by mulching and keeping a even moisture level.


Well-Known Member

Have 8 3 gallon plants in coco. Week 4 -5 of flower, synthetic nutes, neem spray once a week for ipm. Had a bit of a fungus gnat problem so I did the standard procedure. Dried out the medium, flushed with hydrogen peroxide, sprayed neem, dried out the medium again, flushed again, sprayed neem again.

Gnats are still present which is usually never the case after that combo.

My new tactic is to just permanently run hydrogen peroxide in my drip irrigation. My thought is, if the gnat eggs could never hatch because of the peroxide, I won't slow down my plants growth by having to dry out the medium every time. And in two to three weeks all the larger gnats who weren't leaving anyway will be dead.

I tried looking for some info on this before but couldn't find anything. Let me know what you guys think!


Well-Known Member


Active Member

or you can increase the soil biology to eat the gnat larvae before it grows wings and flies away. And you do that by mulching and keeping a even moisture level.

Yeah man, this Is why I love organic no-till so much. It's so much less hassle.

Unfortunately, it's a bit more difficult for high output and commercialization which is why I'm trying out the synthetic runs.


Active Member

Each stage of the critter's life cycle has it's own "length". And each stage requires a different approach, and/or has multiple approaches that may work better or worse than the other, or benefit from using both.
I wouldn't go too overboard with the h2o2 (ie too frequently), depending on strength of mix (don't remember exactly what strength I used.)

But wettable sulfur powder is very cheap and is also something I think is a staple IPM product everyone should have some.
Yellow sticky traps aren't that expensive. Get a 60 pack of the large ones (maybe. 8"x4", can't remember) on amazon and you can cut them in half to get more out of them. They're double sided, too. Peel one side, use it, then cover it and peel the other side. Unless you hang it in "free air" where you can catch the fuckers on both sides. Definitely put some at soil/pot level, lay them on/across the lip or rim of the pot if you can, even with both sides exposed (sticky). The adults are constantly going into the medium to lay more eggs. So you get them coming and leaving.
They are attracted to the color yellow (and other bright colors I think, maybe), and they are attracted to light too. So, put the traps where grow light is hitting them (both below the canopy, like on pot rims, and hanging or placing them on walls or whatever).

Spray wettable sulfur mix (water, sulfur, and some surfactant - peppermint soap works great) on the top of the medium (maybe after water/feeding). Spray the planter drain holes. Spray the entire plant, bottom and top of leaves, and stalk -- but note when this dries it leaves a visual bit of sulfur power on the surfaces and leave - which is fine in veg. Don't confuse it for powdery mildew (which sulfur also tells to fuck off).

When you think you've defeated them, assume you haven't. They've found some bit of organic shit to eat in a nail/screw/staple hole or crack in something - or they're just hiding there waiting to rebound - so, keep new yellow traps up as an indicator of when/(if) those ones come back. Get those last 'sneaky' ones.
Probably keep spraying the top of soil and planter drain holes with sulfur mix as well.

Make sure it's just wettable sulfur, nothing else in it. It needs to be shaken and mixed well, and shook every. 30seconds or so while spraying to keep well in solution.
Something like this, not the one I use, but should be the same:
Good air movement will also help push the adult fuckers into the yellow traps.
Sometimes I would just stand still in a corner or something and watch where they'd like to land. Or tap a continuously with an object to see if/when they'd come out and where from.

Edit: I wonder how many spelling errors ^.

I'll give this a go. Sulfur is hard to come by where I live but I will start to look for it. Would be nice to use it as a dunk every time I re-pot my girls.

Think I'm going to let my medium dry out. Try to catch the majority of the big ones with yellow stickies and apple cider vinegar. Drench the roots with H2O2. Then hit them with hella microbes and BTI. Hopefully, after that, microbiology could help regulate them. I really do not have the time/patience to put up with all of this work much longer.

Watch the video: Σε συναγερμό για το κουνούπι-τίγρης (August 2022).