Mosquitoes have been discussed in a number of BOTWs – https://riveredgenaturecenter.org/bug-othe-week-floodwater-mosquito-an-homage/ and

https://uwm.edu/field-station/bug-of-the-week/psorophora-ciliata-aka-the-shaggy-legged-gallinipper/ – this is the first (with a few new words and pictures).

And remember – bug zappers don’t kill mosquitoes.  The New York Times Wirecutter section says, “Bug zappers kill bugs by the thousands. But there’s a problem: They kill the wrong bugs. They are ineffective against mosquitoes and other biting flies, and their otherwise indiscriminate killing can disrupt pollination and generally throw the environment out of balance. Plus, the force of their electrocution can spew a mist of disease-ridden bug parts out into the air.”

2014 – Who hasn’t seen the postcard (and keychain and license plate holder and t-shirt and coffee mug) that trumpets the mosquito as our state bird?  It’s the insect we all love to hate (they are the very definition of the word “swarm”), but behind the legend lies a fascinating animal.

Yes, there are a lot of them – about 3,500 species worldwide, 175 in North America, and 50 in Wisconsin.  Mosquitoes (mosquito is Spanish for “small fly.”) are in the Order Diptera (“two wings”) and they are in the family Culicidae.  Some people think they’re kind of pretty (including the BugLady, when she’s not inhaling them). 

Yes, they grow up fast.  Eggs are laid on the surface of the water, on floating leaves, or in a spot just above the water line that will subsequently flood.  They generally hatch in a few days, and it takes about month to morph from egg through larva (called a “wiggler”/”wriggler”) (because twitching is their mode of locomotion) through pupa (“tumbler”) (because their mode of locomotion is tumbling) to adult, but in some species, development is telescoped into 10 days.  Mosquitoes don’t live very long – males for about a week and females for two or three.  Depending on species and location, there can be several generations per year. 

Some species of mosquito overwinter as fertilized females in sheltered spots (or in basements, which explains why the BugLady sees the odd mosquito flying around her house in January), and they’re raring to go when spring comes.  Other species may overwinter in a state of delayed development called diapause in any of the above stages, resuming growth when the water warms in spring. 

Yes, they are adaptable.  Eggs develop in wetlands but also in birdbaths, puddles, pails, flower pots, old tires, and the dog’s outside water dish (if you put water in it, they will come).  The first line of defense in knocking down residential mosquito populations is getting rid of these man-made sources of standing water. 

Yes, they do bite.  Females mate only once, but they may lay several “clutches” of eggs.  Males, newly emerged females, and non-egg-laying females feed on nectar and other plant juices, but before each cluster of eggs that she lays, a female must ingest a (high-protein) blood meal (in some species, the blood-letting starts with the second batch of eggs).  Some mosquitoes include humans on their list of possible donors; others restrict themselves to birds, reptiles, amphibians, or non-human mammals. 

She injects, with her saliva, small doses of anticoagulant and anesthetic to aid the process (the resulting red, itchy bump is caused by your body’s histamine reaction to the injected proteins).  Then she ingests so much blood that taking off seems impossible.  A mosquito’s abdomen has expandable tissue between each segment and also between the harder upper and lower surfaces of each segment, so it stretches both vertically and horizontally. 

The BugLady once found a decent-sized snapping turtle digging a hole to lay her eggs in at dusk and, of course, got as close as she could to get some pictures without disturbing the process.  She was AGHAST when she put the pictures up on the monitor and saw that the soft (but still armored) parts of the poor turtle were covered by tiny mosquitoes, and that they were even on her shell.  And that the grass around the turtle’s head was littered with mosquitoes that were too bloated to fly! 

Most mosquito wigglers eat the algae, bacteria, debris, and zooplankton that’s floating around in the water with them.  Some species are predators, and a few even eat the larvae of other mosquitoes.  Wigglers are important food chain “middlemen” between the tiny organisms they feed on and the fish, amphibians, reptiles, birds and the other aquatic insects that prey on them.  Adult mosquitoes are an essential food for bats, birds, dragonflies and damselflies. 

Yes – Female mosquitoes of some species are notorious transmitters of diseases caused by various viruses, protozoans, and nematode worms (the warmer winters we’re having due to Global Climate Change are allowing some tropical diseases like dengue fever to move north again as the mosquitoes that carry them extend their range).  These causative agents generally set up shop in the mosquitoes’ salivary glands, which ensures a free ride into the blood donor’s body (Remember to give your dog it’s heartworm medication). 

More fun facts about mosquitoes:

• That annoying hum is actually a love song.  He sings alto, and she sings tenor, and when they hear each other (they sense sound with their antennae, and the male’s antennae are quite fancy) (some males have big, hairy palps -sensory adjuncts to the mouthparts – too), they vary their tone – by changing the frequency of their wing beats – until both are humming at the same pitch.  Romance ensues.

• Some species of mosquitoes prefer to lay their eggs in the seclusion of a small pool of water that is trapped in a plant; these reservoirs are called phytotelmata (“phyto” means plant and “telma” means pond) (the singular is phytotelma).  A specialized bog species, the harmless pitcher plant mosquito (Wyeomyia smithii) grows only in the water of the purple pitcher plant (Sarracenia purpurea).  Tropical species of Wyeomyia develop in bromeliad “tanks.”  Holes in trees where rainwater collects are a common kind of phytotelma.

• Wyeomyia smithii turns out to be a pretty interesting critter. Its eggs are deposited in the new leaves of pitcher plants.  The larvae/wigglers are considered top predators in the community of organisms that inhabits the pitcher plant’s water reservoir.  They feed on bacteria and mini-animals in the pitcher plant’s water, and while they do eat some of the bits of partly decomposed insects that were meant to nurture the pitcher plant, they feed on organisms that feed on bacteria, ensuring a diverse crop of bacteria to decompose the insects that fall into the pitcher plant’s water.  They overwinter in the pitcher as larvae, frozen in its water.  For a thorough biography of the PPM, see http://animaldiversity.ummz.umich.edu/accounts/Wyeomyia_smithii/.

• There’s even a mosquito that helps with mosquito control.  Elephant/treehole mosquitoes in the genus Toxorhynchites are big, primarily tropical, mosquitoes.  According to bugguide.net, one species, Toxorhynchites rutilus https://bugguide.net/node/view/2168964/bgimage, ranges from Connecticut to Florida to Texas to Kansas.  Turn them loose, especially in a manmade water tank, and they will feed on the wigglers of other species (and of their own), and they do not require a blood meal.  Everything one might want in a mosquito! 

And yes, for reasons that are not completely clear, mosquitoes are more attracted to some people than to others.  A lot of scientific experiments have been done and anecdotal explanations offered (an individual’s general “sweetness” of temperment is apparently not a factor).  It may be a response to clothing color (they prefer dark), perfumes (love ‘em!), blood type (they prefer Type O), pregnancy (yes), body heat, particularly aromatic sweat, and/or distinctive carbon dioxide exhalations.  Ms. Mosquito can detect CO₂ in the air from 25 yards away and home in on the source. 

And by the way, the BugLady would like to suggest that whoever keeps writing “Mosquitoes are crepuscular – active at dawn and dusk – and they rest during the heat of the day” has only visited God’s country in the snow. 

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/