Mosquito Larvae identified at my house at Metric and Rundberg, Austin, Texas, Spring 2016

Larvae examined on 4/30/2016 - Culex larvae

This is a slide show.  If you click on any given image it will show it full size.  

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I bought an old low power microscope on Craigslist - 25x to 100x.   I also tried out photographing through magnifying lenses with my cell phone.  I had to make an adjustment on the microscope to expand my field of vision; it would have helped on the bigger microscope as well.

The toilet paper roll, with a small amount cut off of one end, holds the cell phone camera off the lense a little bit.  

Here are my new photos.  I got much clearer photos of their heads.  All of these came from my tire, which yielded only 3 larvae today.

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Here are photos of Culex pipiens larva and Aedes larvae online

The picture below of what several genuses look like under a magnifying glass, clearly shows in broad terms the differences between these genuses that are broken down in detail below.   Notice especially the difference in antennae, anal segments and siphons between Culex and Aedes.  However, some Culiseta species look similar to Culex at this level.

Having been assured that my larvae have to be KEYED for proper identification, I had another go at it.   I used a larva from my tire that was the youngest larva several days ago but by now is surely 4th instar.   The keys are written for 4th instar larvae, or atleast 3rd instar.   (Larvae molt through four stages.)   Below the UT El Paso mosquito identification guide and the Workbook on the Identification of Mosquito Larvae have the most comprehensible versions of the keys.   The UT El Paso guide is intended to make it easy to identify larvae at the genus level.   

The fact that any mosquito laying eggs in my tire ovitrap is a container mosquito narrows the likely species down a great deal.  That would pretty much be Aedes and Culex.   Also, the larvae were found hanging at 45 degree angles from the surface of the water.   They weren't hanging horizontally like anopheles mosquitoes.  They clearly aren't larvae that hook onto the bottoms of plants, or the leaves of plants, or that only grow in crab pits, pitcher plants, or similar sorts of plants.   Mosquito larvae found in containers are overwhelmingly likely to belong to Culex or Aedes.  Since it was found in an old tire, we pretty much already know it is Culex or Aedes.   

The first consideration in the keys is, does the larva have a tail?   That is, does it have a siphon?   The siphon is an elongated organ coming off of Segment 8, through which a mosqito hanging from the surface of the water breahes.   Just one genus, Anopheles, has no siphon.   Anopheles also has round groups of little tufts and no long hairs on its rear segments, to help with hanging from the surface of the water in a horizontal position.  

If it does have a siphon, the next question is, does the siphon look peculiar?  Several groups of mosquitoes have hook shaped siphons for attaching to plants under water, instead of hanging from the surface of the water.   

My larvae have perfectly ordinary siphons, consistently with having been found hanging from the surface of the water at a 45 degree angle, in an old tire.

Some keys look next at the pecten, which is a line of tooth-like structures at the base of siphons of some mosquitoes, and others start with looking at tufts of hair on the siphon, and then the pecten.   Broadly speaking, there are four possible configurations.  The fine line of small lines is the pecten.   The tufts and longer lines are hairs.

Whether there are pecten seem to best delineate members of genuses from each other that otherwise look very similar.   

It took real work to see anything resembling a pecten on these larvae, even though there wouldn't be container mosquitoes that don't have pectens.  Aedes and Culex are examples of species that have pectens.  

On several photos, including an entire set of photos of the same view, I saw what looks like a pecten, though the chance exists it's really something else seen around the edge of the siphon.   The first tuft of hair is just before the end of the pecten, which it would be in a Culex pipiens mosquito.   I was only able to see the pecten at close to 100X.   However, I have quite a number of very good photos of the syphon showing that I couldn't find any sign of a pecten.   It is possible that it requires the siphon to be at the correct angle to see it, meaning the larva has to cooperate.   

One can clearly see that the pecten, or the location where the pecten would be, is followed by several tufts of hair at regular intervals.  The arrangement matches 3c in the diagram above.   

I realized that while I recall three tufts in a line, and a fourth smaller one off to the side, on these larvae, I don't have a good photo of the entire siphon that clearly shows them.   Below is what I could do with them, and it shows a rather odd distribution of those tufts.  

There are TWO tufts in a line after the pecten, and a third smaller one off line a little further down, and then another smaller tuft (one or two hairs, maybe) further down on the other side of the siphon.

Then it gets odder.  The first of the two large tufts in a line has another tuft parallel to it.   There is a third tuft offline farther down, that one can just make out.   On the other side, in between those, are two tufts that might be one hair each, it's hard to tell.   One of them can just be made out.   

Here is a better view of someof the tufts, and it gets stranger, as one can just make out what appears to be a line of fairly long hairs on the opposite side of the siphon.  It is slightly clearer in the full sized photo.

If one pair of siphonal tufts or hairs is present, like in the lower right drawing above, the larva would be Uranotaenia, Psorophora, or Aedes.  One can clearly see that these larvae have atleast three tufts.  (Pairs of them?)   

Urotaenia have a sclerotized plate on the 8th segment instead of a comb, and heads longer than wide.   Most have four spines on their heads.   These larvae have a comb on the 8th segment, and heads wider than long.   

Of non-anepheline mosquitoes that don't have pectens:

Mansonia have a tapered air tube because they attach to roots of aquatic plants.

Toxorhynchites has a plate instead of comb scales on the 8th absominal segment, and a rectangular head modified for eating other bugs, and the larvae grow to be huge and brownish, with many spine-like hairs.

Orthopodomyia has 2 rows of comb scales, an anterior row with small scales and a posterior row with longer scales

Wyeomyia has a single row of comb scales, and an anal segment with no ventral brush (that big tuft of hair my larvae have on their anal segments).  

 

Psorophora would have tufts of the median ventral brush, which is the tuft of hair on the end of the tenth segment by the gills, attached to the saddle, which encircles the 10th segment completely.  The saddle is a sclerotenized plate that covers all or part of the 10th abdominal segment.  I'm not able to make out the saddle or if the tuft attaches to it, but drawings of the tuft with Psorophora show it growing along most of the ventral side of the 10th segment.  

If the ventral brush is behind the sasddle plate, as in the picture below, or the saddle plate does not encircle the 10th segment completely, the genus is Aedes.  I couldn't make out the saddle plate.   

If several pairs of tufts or single hairs occur on the siphon, the mosquito is Deinocerites, Culiseta, or Culex.

Deinocerites has characteristic pouches on the sides of the head.   These larvae do not.  What is more, Deincerites only breed in crab holes.   These larvae were found inland in a tire.

If there is a tuft/ pair of tufts near the base of the siphon, like the upper left figure above, and a ventral row of tufts, straight hairs following the pecten, or no additional hairs or tufts the genus is Culiseta.  

If it looks like the following (which is exactly what it does look like); if basal tufts are absent and if a row of tufts or scattered hairs occurs along each side of the siphon, the genus is Culex.  

There is a large tuft of hair near the base of the siphon.  I can't make out if it is ON the siphon or on the 8th siphon.   This mosquito basically has two large tufts of hair on its hind end; one in the middle end of the 8th segment, and the other near the base of the siphon.  I think there is a smaller tuft on the 8th segment just before the 10th segment.  

Here is what Culex quinquefasciatus would be expected to look like.  Notice how close the tuft of hairs on the right is to the siphon; not easy to tell under a microscope where it really originates.

Here is allegedly what is meant by tuft or hair at the base of the air tube.

To me that doesn't look like the base of the air tube, and notice that the tuft below the base of the air tube is also there.

Here is another rendition of where that tuft of hair would be.  It too is in the middle of the pecten, but notice that the relative size of the pecten places it close to the base.  On my specimens it isn't possible to make out the pecten very clearly.

Here, in key format, is another image.  Once again, the basal tuft is depicted as about a third of the way along the pectin, which once again isn't itself all that long.  Once again there is also a tuft on the 8th segment just before the siphon, and my larvae have just one tuft near the base of the siphon and not two of them.   

Here is an image of what the tufts near the siphon look like under a microscope on a Culeseta, and it's darned hard to see there are two tufts, let alone where each originates.

Going back over my images, I can't find any where the tuft of hair clearly originates on the siphon.  Often it appears to originate somewhere behind it.   

 

These two species are easy to confuse.  According to  Handbook of the Mosquitoes of the Southeastern United States, King, Bradley, Smith and McDuffie, The eggs of Culiseta are laid in rafts, similar to those of Culex, and breeding is in more or less permanetn water collections.

"The eggs of Culiseta are laid in rafts, similar to those of CuEex, and breeding is in more or less permanent water collections. The female palpi are short, the male palpi somewhat longer than the proboscis, the male antennae bushy, the scutellum trilobed, and the postnotum bare. The wing has a tuft of hairs on the underside at the base of the subcostal vein, the second marginal cell is as long as or longer that its stem, spiracular bristles are present, postspiraculars absent. The tip of the abdomen is bluntly rounded, segment 8 visible, the cerci retracted. The dististyle of the male is slender, unmodified; the basistyle has a basal lobe bearing numerous bristles but is without a subapical lobe in our local species, and claspettes are absent. The larva has the general characteristics of genus Culex but differs chiefly in having a hair tuft at the base of the air tube and a paired ventro-lateral row of single hairs beyond the pecten (subgenus Culiseta), or a single mid-ventral row of small tufts beginning before the end of the pecten (subgenus CZimacura) . Only two species of this genus are found in the Southeast."

"Culiseta melanura is a medium-size mosquito, resembling a species of Culex much more than typical Cd?. It can be recognized by its unusually long proboscis and dense wing scales. The larvae are found in small permanent collections of water, with or without vegetation. In Alabama they were found in water around the bases of trees and stumps, seeming to prefer places chosen by Aedes thibaulti (,%??) ; in Arkansas they occurred in abundance in October and November in open pools in muck lands (157) ; and in southern Mississippi they were collected in small grassy ponds of dark, acid water in a wooded swamp, in water 126 AGR. HANDBOOK 173, U. S. DEPT. OF AGRICULTURE beneath hollow stumps and under the roots of trees, and once in a shaded barrel with A. triseriatus (225). In New Jersey, they were found in holes of spring water in sphagnum bogs (29~). "

"LARVA.-Antenna1 tuft large, multiple, set in a constriction at about the apical fourth of shaft as in Culex. Lower head hair long, single, the upper with three or four branches, about half as long as lower. Body glabrous. Comb, a single even row of long, barlike scales, each rounded and finely fringed, the lateral margin scalloped. Air tube about 6:1, with a pair of small, double or triple hairs near base, and a long single row of about 15 short, multiple hairs on the mid-ventral line of tube beginning before the end of the pecten; pecten spines with two or three small side teeth near base. Gills about as long as the segment."

The University of Florida medical entomology laboratory key says that culex quinque-fasciatus  should have index 3.8 to 4, bulbous, 4 pairs of hair tufts, 2 basal tufts multi-branched.   This is one of the laboratories that consideres Culex pipiens to be the northern subspecies.  

My high power views of the siphon never show all of the hair tufts, but it is clear that they aren't all lined up.  

University of Florida Photographic Guide to Common Mosquitoes of Florida says Culex species have more than one hair tuft on the siphon.   

Both University of Florida guides ignore Culiseta, which most closely resembles Culex.  

Aedes would look more like this.

 

 

The arrangement of tufts of hair on the 8th segment between the shiphon and the tenth segment with the gills, and the location of the tuft of hair (when there is one) on the tenth segment, are also important in classifying mosquitoes.   It appears that the tuft of hairs on the end of the tenth segment is attached to the end of the side of the tenth segment.   

 

It matters whether the gills are longer than the siphon.  I trust they mean, if the gills plus 10th segment are longer than the siphon.   In any case, either they're the same length or the gills are clearly shorter.   They are not, however, half there, like in Aedes.  See above plus this one.  The four long hairs with the gills are another story, however.

The siphon itself varies in length relative to its width, is slightly bulbous, and length is between 4x and occasionally closer to 6x of its width.   

 

Two more details that are important are the lengths and relative lengths to each other, of the gills at the end of the tenth segment, and the number and length of the four long hairs that on these larva extend far past the gills.   The gills are very similar in length to each other but not identical; two seem slightly longer than the others, and they aren't the same length as each other.  

 

There are other details as well.   

Notice in the pictures below, that the two abdomen segments closest to the thorax have more side hairs (setae) in their tufts than the other segments.  There are actually two long hairs and two short hairs, per tuft.   

Culex nigripalpus, a mosquito that is more numerous and more important to spreading West Nile virus to humans in the south, allegedly has no hairs on its 4th segment.  I have the very strong impression that these larvae had no segments without hair tufts.

The photo below, left full size because it is blurry, clearly shows tufts of hair on the 4th segment, and even the 5th.

I personally also noted the pointed appearance of each segment at the base of the tufts of hair.  Not every kind of mosquito has segments that resemble these; some have rectangular segments, some have more deeply colored segments, and some even have bands of chitinous material across each segment.  There are also mosquitoes that have no hairs at all on just one segment.  

 

The side tufts on the thorax, which has several tufts of hair because it consists of several merged segments, contain more hairs yet, and they are often in pairs of tufts.

Some larva are characterized variously by heads that are longer than they are wide, and pouches on the sides of their faces.  These larva have heads that are wider than they are long, and the outsides of their heads are pretty much occupied by their eyes - no side pouches.   

Species of mosquito larvae are often distinguished from each other by the way hairs are arranged around their mouths, and on their heads.  I didn't get much dtail at all on the hairs on their heads, though one can vaguely make out what might be a couple of them.   Above is as much detail as I could get on the tufts of hair on the fronts of their faces.   

Clearly their antennae don't have multiple branching tufts, and, unlike Aedes ageypti and Aedes albopictus (but not every Aedes), there are actual tufts of hair on their multi-segment antennae.

A proper photo of the antennae proved hard to get.

It's hard to tell, but the tuft on the antenna has after it a second tuft of two hairs, and then a further segment.   

Here is the head and thorax together.   Head appeared to shrink relative to thorax as the larvae got older.

Here is the larvae's comb.   Some mosquito larvae have combs, some don't, and they differ widely in arrangement and form.   It could be seen at close to 100X power.   Comb scales are most important if the larvae don't have pectins.  They may have alternate structures instead.  There are mosquitoes with two rows of comb scales, some of which are very long, that look similar, but this looks distinctly like three or possibly four rows of comb scales.   One is also supposed to look at individual comb scales under the microscope; I don't think so.   My microsurgical skills aren't that good.   

Most Culex mosquitoes have "many in a patch".  Evidently if there are more than two rows, it becomes a patch.   If there are 9 to 22 or 15 to 22 comb scales in a patch the chart I'm looking at (From the University of Florida medical entomological laboratory) says so.  One cannot count all the scales below, some being out of sight; I count 21 of them.   

Photographic Guide to Common Mosquitoes, from the same source, just says there is more than one row of comb scales, for Culex.

One of the larvae hatched into a small dark mosquito inside a clear plastic container.

Basically, I think this is a Culex, probably quincquefasciatus.   However, I have questions about the pecten and the tuft near the base of the siphon.   Logically these larvaes must have pectens, but it is not impossible that a stray Culiseta laid eggs in a tire.  

For the past week I've not found any mosquito larvae in my tire; only dead black flies floating on the surface.  I wondered if perhaps the chemicals the rain washed from the wooden balcony above into the tire, turning the water brown, killed the bugs or something.  I gave up and started over again, cleaned out my tires, used bottled spring water.   I used more tires as well.  Seems Aedes like to hop back and forth between pairs of tires when laying eggs, or something.  Fussy little buggers.   But I noticed a lot of what looked to be midge larvae (would go with the floating black flies on the surface, as black flies are a kind of midge) when I cleaned out the tire, so I saved them to have a look later.   In with the midge larvae were several fresh-hatched looking mosquito larvae.   When I looked at one under a microscope, it looked very different, very likely an Aedes.  I put it back with its mates, after removing the midge larvae and adding some food, to grow into bigger larvae.  I suspect the midge larvae, which are bigger, have been eating the mosquito larvae, which is perfect from a mosquito control standpoint, except hard to tell if mosquitoes are even laying eggs there, let alone what kind of mosquito.

Supporting that suspicion is that I found some specks that looked ot be either mosquito eggs, or uniform looking dirt, on one of the pieces of paper towel, put it in a container with a little food, and forgot about it for a few days.   When I found it today it had six small mosquito larvae in it.   I changed their water, fed them, and left them to grow.   The odds are good they are Aedes, since Culex prefers to lay eggs in the water itself.  

So here is my new setup.  It seems Aedes may actually prefer contaminated brown water, so I put in more leaves than previously.  24 hours later there are already dead black flies floating in it...   A mosquito expert suggested to me that flat wooden wood pieces wrapped in damp paper towel may work better than floating paper towel on top of something, even though usually those were damp.  I put varying amounts of dead leaves, many of them found under rain spouts, a couple of spelt berries, a little brewers yeast and spirulina powder, in each tire.   The leaves and spelt berries, and probably the yeast and spirulina, feed microorganisms that are actually what the mosquito larvae eat, which is why mosquitoes want to lay eggs where there is organic matter.  I varied the size of the tire and the depth of the water, as well.

 

 

 

 

Aedes larvae

These larvae both came from my tire.   One source was baby larvae found in the water I scooped out of the tire, among the midge larvae; my guess is they are mosquito larvae that just hatched and the midge larvae didn't eat them yet.   The other were hatched one one of the pieces of paper towel on one of my floating pieces of foam paper plate, so they were laid by mosquitoes that lay eggs near but out of the water.   

They are clearly Aedes larvae.

According to the Mosquito Identification Guide; Larval quick Key, Florida Medical Entomology Laboratory web site, Aedes should have:

  1. 1.  Only one row of comb scales

  2. 2.  Siphon/ air tube present

  3. 3.  Pecten spines on siphon

  4. 4.  Siphon has no basal hair tufts on siphon (among the basal pecten scales), and has one to many pairs of hair tufts or single hairs beyond the pecten.

  5. 5.  Siphon has only one pair of hair tufts or single hairs.

  6. 6.  Head is wider than long, no spines on head.

  7. 7.  anal segment not completely ringed by saddle or not pierced by the ventral brush.

I had initial trouble finding the ventral tuft at the base of the siphon on my specimens; on some photos below it does not show.  However on actually all but one specimen the ventral tuft is clearly found, and it appears in most of my photos.

They have combs, of a single row of scales.  The initial photos are too blurry for me to discern what species' scales these are, which is frustrating, as the scales are large enough that that would probably be possible if the pictures were clear.  But after meeting with Alex Wild and getting some tips on lighting and mosquito positioning, it is clear that these are Aedes aegypti scales.  

The saddle is only partway around the anal segment.  This is clearer and much more consistent in the newer and higher quality images.   

It was hard to discern if the tufts on the thorax had heavy hooks on the base, but I have quite a number of photos that appear to definitely show heavy hooks.  With Alex Wild's entomology lab microscope there are clearly large hooks at the base of the tufts on the thorax, and that is also clear on my own microscope at high power.   

They weren't at all cooperative with my efforts to photograph them.   That the photos are all blurry was partly a result.   Unlike Culex larvae, which calmed down if you chilled them, or even if they were in only a drop of water, when they ran out of room and oxygen, these larvae kept vigorously thrashing around.   This is consistent with the reportedly ability of Aedes larvae to grow in a drop of water.  I have to wonder if they can breathe air.  If I put them in the refrigerator, they were vigorously active again two seconds after they warmed up.  If I put alcohol on the slide and then rinsed it in fresh water, these came right back to life.  I literally had to kill them to get them to hold still, and then you get absolutely no detail on their heads.

The best way to kill them is to leave them in 70% rubbing alcohol for a few minutes.  They also visualize most clearly under the microscope if one puts plenty of the alcohol solution with them.

Aedes species can be discerned from each other partly by what is on their heads, and I tried hard and fruitlessly, especially to get the structures on their faces.

 

Looks like two tufts of hair stuck together.                                         Two tufts of hair on opp sites of anal segment

Same thing?

Shows both the possible ventral tuft and the siphon tuft.

These two photos show what looks like an actual ventral tuft.  

With better technique and new speciments, I got clear ventral tufts.  Below one can also see the saddle partway around the anal segment.  

It is well to keep in mind that Aedes tail tufts are not as bushy as Culex quinquefasciatus.  

Comb scales

These scales look more aegypti-like than albopictus-like, but it's hard to tell.  Aedes aegypti have side spicules on their comb scales, while Aedes albopictus comb scales are straight.   

Alex Wild's microscopes allowed me to see the comb scales only slightly more clearly, but he gave me some tips on how to get more out of my optics.  One issue I have with clarity is lighting and the fact that I can't control how it hits my objective, on my low power microscope.  But his dissecting microscopes couldn't clearly make out the comb scales at 100x.

Here is what I could do at 100x.

One can barely make out what appears to be a small spicule.  But then it occurred to me that my problem might be that I always see these comb scales from the side, while their distinguishing features are usually shown from a frontal view.   No matter how I fiddled with that larva, it still lay on its side, so I tried Dr. Wild's advice of squashing the mosquito slightly with a microscope slide (over the pitted slide).   Now look what I got, at 100x.

There is no question now that this is Aedes aegypti.  

At 500x, I got

At 500 x, I got a cloudy image, and I could only focus on one feature of the mosquito at a time.  But the shape is what matters.

Saddle part way around anal segment

 

Pecten and single tuft of hair.   Notice the clear ventral tuft next to it.  

Here are clearer images of the pecten.  What is more, it appears that there are pecten and one tuft on two sides of the siphon.

 

Here are some tuft attachments on the thorax. Some appear to have hooks and some don't.

 

Here are what the thorax hooks of Aedes aegypti and albopictus look like.  The guides don't say what the hooks of other Aedes species might look like.

Here are some thorax tufts from my larvae at high power.  Again, it is clear that this is Aedes aegypti.  

Several views of head and feeding apparatus on front of face.  These vary in appearance by Aedes species.  One can also get an idea where some hairs attach to the head, which also varies by Aedes species.  These are followed by higher power views of the head.

Below are 100x and 400x, much clearer, which show where hairs and tufts are actually found on the larvae's head.

Here is what matters on their heads.  (What matters on their tails is here as well.)  From A RAPID IDENTIFICATION GUIDE FOR LARVAE OF THE MOST COMMON NORTH AMERICAN CONTAINER-INHABITING AEDES SPECIES OF MEDICAL IMPORTANCE, Farajollah and Price.  See below.  

The first image in the second row continues around the front of the face from the base of the antenna.   The third image in the second row is farther back on the top of the head than the first image.  The last image is the back of head and neck.

Images of a mouth brushes, and one of pair of tufts behind them on back of head.   

 

Antenna

According to Farajollahi and Price, Aedes aegypti and albopictus are together distinguished from other Aedes species in North America, by the following features: pecten teeth on siphon evenly spaced, siphonal tuft inserted beyond pecten teeth, and comb scales are alligned in a single straight row.   They are distinguished from each other by:  Aedes aegypti has comb scales with prominent subapical spines resembling a pitchfork, head hair 7-C single, and lateral sides of thorax with prominent black hooks.   Aedes albopictus is distinguished by comb scales with straight and long median spine, resembling a htorn, head hair 7-C double, lateral sides of thorax with small hooks or no hooks.   Based on that, these would probably be Aedes aegypti.

Some keys also look at the hairs on the head.  The anntenna and lower hairs are single.  Some keys emphasize that Aedes aegypti has one single hair near the middle of the antenna, and all other Aedes have tufts in that location; I have yet to see a hair in the middle of the antenna, and many keys don't mention it, and some microscope photographs of the antenna don't show them.   The photo in the key above neither shows a hair on the antenna nor mentions any.   It is possible that the antenna has to be right way around to see it.   Another feature is that the mouth brushes have 30 or more hairs; the mouth brushes of these larvae are quite bushy.  

I took my larvae and some pupae out to Alex Wild, an entomologist at UT Austin.   An adult of the Culex lot above unfortunately lost half its tufts of hair by the time he got a chance to look at it, and couldn't be keyed.   Under the laboratory dissecting microscope, the Aedes larva looked far clearer.  Bright electric light helps.  We couldn't get our cell phones to line up suitably for taking photos.  However, the larva had a nice ventral tuft on its anal segment, with five or six hairs.   It had definite vivid hooks attaching its thorax tufts.   On the comb scales the magnification wasn't quite up to the task, but we could just make out what appeared to be little spicules on each side of the bulge on the comb scales.   Dr. Wild said that he has had far more luck finding adult Aedes aegypti around Austin than Aedes albopictus, especially in his own garage in west central Austin.   

Since then, both Alex Wild, and Elizabeth Brown of the Travis County Cooperative Extension, have been able to examine adult mosquitoes that emerged from the pupas and larvae that I took them, and both confirmed that these are Aedes aegypti.

 

Mosquito  identification resources

University of Texas at El Paso Mosquito Identification web site.   Easy to follow slide show key to identifying mosquito genera, larvae and adults.   

Wikipedia article on mosquitoes, with general discussion of mosquito biology and anatomy charts of larvae and adults.   

Waterwereld: The common house mosquito   Biology of mosquitoes, usefulness for fish food, usefulness of fish for mosquito control, diagram of mosquito larva anatomy.   It is controversial whether the common and southern house mosquitoes are subspecies of Culex pipiens.   However they share the ability to carry West Nile virus and other forms of encephalitis.

Mosquitoes:  Characteristics of Anophelines and Culicines.  Kent S Littig and Chester J Stojanovich.  Focuses on Anopeles, Aedes, and Culex (the three primary genera of medical importance in the U.S.)

Mosquitoes:  Characteristics of Anophelines and Culicines.  Kent S Littig and Chester J Stojanovich.  Focuses on Anopeles, Aedes, and Culex (the three primary genera of medical importance in the U.S.)  Same document from texasmosquito.org   

Pictorial keys for the identification of mosquitoes (Diptera: Culicidae) associated with Dengue Virus Transmission   Exclusive key to Aedes species, but includes actual pictures of what scales, combs and hooks look like.  

Workbook on the Identification of Mosquito Larvae.   Pratt, harry D and others.   Public Health Service, Atlanta, Georgia.   Basic and detailed enough for a student to easily follow.  

Classification and Identification of Mosquitoes of New Mexico

A Handbook of the Mosquitoes of the Southeastern United States.   King, Bradley, Smith & McDuffie.  Agriculture Handbook No. 173, Agriculture Research Service, United States Department of Agriculture.  Very detailed text on mosquito collection and identification.  

Mosquitoes of the southeastern United States.  Burkett-Cadena, Nathan D.  (Tuscaloosa: University of Alabama Press, 2013) UT Life Science Library, QL 536 B916 2013.   Parts can be previewed at Amazon.   Someone on the Texas entomology listserve recommended this book.

Key characters for larval Aedes spp.  identification in California.   California Department of Public Health.   Photos of what anatomical features, such as hooks, look like.     

Identification Guide to the Mosquitoes of Connecticut  Detailed key with detailed illustrations.  

Identification Guide to Adult Female Mosquitoes of Saginaw County - photos of what the features look like.

Mosquito Identification Guide: Larval Quick Key  University of Florida, Florida Medical Entomology Laboratory.  

Mosquito Identification Guide: Adult Quick Key  University of Florida, Florida Medical Entomology Laboratory.

Photographic Guide to Common Mosquitoes of Florida   University of Florida, Florida Entomology Laboratory

SOUTHCOM Mosquito Genera Identification Key  U.S. Army Public Health Center.  For central and South America, but evidently there isn't one for North America.

Aedes larvae  Clear color photographs with distinguishing features of Aedes larvae

Aedes Albopictus Florida Medical Entomology Laboratory, University of Florida  Clear photos showing anatomomical features like scales and hooks

Aedes Aegypti  Florida Medical Entomology Laboratory, University of Florida  Clear photos showing anatomomical features like scales and hooks

Aedes Larval Picture Key  California Department of Health web site.  Photos instead of drawings, for three Aedes species.  

A rapid identification guide for larvae of the most common North American container-inhabiting Aedes species of medical importance.   Ary Farajolahi and Dana C Price.  Journal of the American Mosquito Control Association, 29(3):  203-221, 2013.  

Culex quinquefasciatus (Southern/ Common house mosquito, very similar to Culex pipiens and arguably a subspecies) Florida Medical Entomology Laboratory, University of Florida  Clear photos showing anatomomical features like scales and hooks, of larvae

The other main genera of mosquitoes are represented on this web site as well.

Culex quinquefasciatus  APHC Entomological Sciences Mosqiuto Species Page, shows in clear photographs, all of the fine anatomical detail necessary to identify this species.

Mosquito species pages/ training aids, Army Public Health Center (under training aids)

Species pages and keys with terms, Army Public Health Center

Walter Reed Biosystemacits Unit interactive key

Culex quinquefasciatus  Wikipedia   Describes relationship between Culex quinquefasciatus, the southern house mosquito, and Culex pipiens.   

Crowdwourcing for large-scale mosquito (Diptera: Culicidae) sampling.   Elin C. Maki, Lee W. Cohnstaedt.  Report on an earlier generation of the North American Mosquito Project, by the USDA.  Citizen science project that addresses the failure of local agencies to track mosquitoes.  Lists the agencies that helped them with their work.  The word Texas is notably missing from the list.  

Citizen-scientists:  Uncle Sam wants you to fight Zika!  The Invasive Mosquito Project.   New incarnation of the North American Mosquito Project.  The USDA and CDC are attempting to use citizen egg, larva and adult mosquito efforts to compensate for the poor job local agencies around the country are doing monitoring mosquitoes, especially disease-bearing invasive species like Aedes aegypti and albopictus.  

Walter Reed Biosystematics Unit  U.S. military public resource on medically important arthropods, includes several kinds of pictorial and interactive identification keys