It takes a curious person to peer at a mosquito’s genitalia.
“Mosquitoes are fascinating insects,” says Richard Lampman, a mosquito expert with the Illinois Natural History Survey, the Champaign-based recorder of biological resources in the state. “They’re the perfect example of adaptation to selection pressure in environment.
“Many people think there’s only one kind of mosquito, but suddenly you find out there are 65 to 70 species in my own state; there are up to 200 species in the United States; and 2,000 worldwide; it’s fascinating.”
The mosquito actually is a fly, because it has two wings. But unlike other flies, mosquitoes have wings with scales.
Mosquitoes also don’t really bite; they have no teeth. The female mosquito inserts its proboscis into the skin to drill for blood, whose protein helps the female produce eggs (male mosquitoes don’t sting humans). The itching we feel after a mosquito bites is the body’s reaction to the anticoagulant injected with the mosquito’s saliva as the proboscis punctures the skin.
Identifying mosquitoes takes special training, but May Berenbaum, head of the entomology department at the University of Illinois, offers a quick and dirty way to separate the species: Check out the mosquito’s butt.
“If it feeds with its butt in the air, it’s an Anopheles. If it feeds with its butt pointing down, it’s an Aedes. If its body remains parallel while it feeds, it could be a Culex. But,” she adds with a smile, “you need tolerance because you’ve got to wait till it’s feeding.”
The thrill of learning what separates the species — coupled with the demand for mosquito-control personnel following the 1999 outbreak of West Nile virus in the U.S. — draws biology students into the mosquito field at a starting annual pay of $25,000 to $30,000, according to Martin Chomsky, business manager of the American Mosquito Control Association. With a biology degree, grads can work with government mosquito-abatement districts or with private mosquito-abatement companies or join chemical companies to develop insecticides and repellents for commercial and consumer use. Or they can become a technical assistant at a university — such as Illinois, Florida, Rutgers or California at Davis — doing the grunt work while studying for a master’s degree in entomology, the branch of zoology that studies insects.
Technical assistants wade into soggy fields and other mosquito breeding grounds to set up traps that collect the insects. They also help their research scientist conduct landing counts, in which they expose skin for a determined period of time and count the number of mosquitoes, that land. (The idea is to kill the mosquitoes before they bite. That’s the idea, anyway.) The assistants also empty traps and take the captured mosquitoes back to the lab to sort and identify them.
Choice of career paths
After a couple of years as a technical assistant and acquiring a master’s degree, the mosquito student could head for the job market or could spend four more years as a research assistant while pursuing a doctorate in entomology in hopes of becoming a curator at a science museum or a medical entomologist, for instance. That’s Lampman’s line of work. Right now, he’s finding out if Culex mosquitoes alone are responsible for transferring West Nile virus from birds to humans.
“Every scientist thinks of himself as a detective,” he says. “We gather circumstantial evidence that points to what’s going on. Finding a direct link to a pathogen is difficult. When all the pieces fit together, it’s fascinating. When they don’t, how can I design an experiment that tells me if this is true or if this is true?”
Research scientists publish their findings and share notes with colleagues and with mosquito-abatement districts.
“Our job is to write up research papers convincingly, so when we talk to people [mosquito-abatement districts, insecticide sprayers, etc.] we convince them this is how you have to change your process,” Lampman says. Colleagues will try to poke holes in the findings, so a scientist must ensure that his or her results are reliable, verifiable and applicable to stand up to the rigors of the scientific method.
“That’s their job,” Lampman says. “They take your puzzle pieces that you make look like the Eiffel Tower and try to make it look like the Washington Monument.”
In a watershed event, the devil’s advocates had to yield in 2000, when, after studying the consistent characteristics of the female and male genitalia, John Reinert convinced the mosquito world that the genus Aedes should be split into Aedes and Ochlerotatus. To most people, that’s nothing. But to mosquito taxonomists, this was big news.
“We’re a tightly knit community,” adds Chomsky of the American Mosquito Control Association. “There’s probably 3,000 to 4,000 throughout the country involved in mosquito control in one way or another, through operational, regulatory and academic activities. They’re such dedicated people. Most of them don’t get paid very well to do what they do. It’s a labor of love. If you don’t love what you do, you find people move out of the field very quickly.”
A popular profession
Finding students to follow in the footsteps of Chomsky, Lampman and their peers is proving easier. The outbreak of West Nile virus in 1999 and federal, state and local expenditures to fight the mosquito-borne disease has swelled the ranks of mosquito people.
“Universities started attracting more students,” Chomsky said. “Suddenly, there was a shortage of mosquito control professionals. States were starting up mosquito-control programs. Funds [to fight mosquitoes] were being approved from the federal and state governments. The growth of workers increased dramatically. There’s been at least a 20 to 25 percent increase of workers in mosquito control since 2000.”
Comparing notes
WNV, as mosquito people call West Nile virus, has changed the annual meetings of the American Mosquito Control Association, as well.
Instead of debating the efficacy of different pesticides, poring over the latest governmental regulations and bemoaning the lack of young blood in the profession, association members now compare notes on their attempts to find out how to stop the spread of West Nile virus.
“Before we were scientist talking about, `Hey, look at this mosquito’ and, `Look at that mosquito.’ Now we’re talking about, `look at that disease and what can we do about it?’ “
The American Mosquito Control Association’s membership has been rising over the past three years to the current levels of 1,600 non-student members and 150 student members, Chomsky says.
Today’s mosquito professional is a far cry from his counterpart of 30 years ago. Back then, fog-spraying trucks trundled down suburban streets on weekly schedules, regardless of whether mosquitoes were a neighborhood nuisance.
Dangers of DDT
The preventive measure seemed to work, and besides, kids loved to dance and disappear into the fog the trucks belted out. But that was before it was widely known that DDT harmed more than just mosquitoes.
It also was before mosquito professionals began paying more attention to mosquito life cycles and draining water from breeding grounds after heavy rains.
The field has come a long way. Now it’s much more about research.
Lampman, of the Illinois Natural History Survey, says he spends about 30 percent of his time in the field, 40 percent of his time in the lab and 30 percent of his time in meetings or writing reports: “If you want grant money, you have to fill out reports.”
He said if he had his way, hewould “spend 15 percent in the field, and let everyone bring me the data. They’re mosquitoes, not butterflies.”
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What’s the buzz
Wait! Before you scrape away the remains of that mosquito you just smashed on your arm, take a closer look. Is that now-crumpled antenna the feathery sensory organ of Orthopodomyia signifera? That flattened mesonotum: Does it contain Psorophora’s telltale line of short setae and scales bordered by a glossy bare area along each side of the mesal line? Our handy skeeter field guide includes a few of the 60-plus species of mosquitoes in Illinois and will identify that squashed bug on your arm. Who needs a high-powered microscope and years of expensive schooling in taxonomy?
Head: Check it out: The palp is as long as the proboscis. Looks like what you’ve got yourself here is the malaria-transmitting Anopheles quadrimaculatus. (How to avoid: Don’t help build the Panama Canal.)
Wing: OK, linking these to a species would be a tough task even for the cast of “CSI: Miami.” So we’ll assume these wings belong to the mammal-loving Aedes aegypti. (How to avoid: Become a plant).
Leg: Does the first segment of the hind tarsus have a yellow middle band in addition to a white basal band? It must be the mammal-loving Oclerotatus sollicitans, which usually won’t follow you indoors (How to avoid: Become an indoor plant).
Mesonotum: A piece of cake. Because the bottom part of the mesonotum has three lobes that are sprouting three tufts of setae, this is definitely the strong-flying Aedes vexans. Probably. Maybe. This entomology thing isn’t as easy as it looks. (How to avoid: Keep moving. Preferably in an air-conditioned car with the windows rolled up)
Abdomen: From the dorsal aspect, if the segments have bright and conspicuous basal bands of white scales (and wide middle scales), your culprit is Culex pipiens, which is most active at dusk and after dark.
Had enough?
If you crave more esoteric skeeter information, visit these websites:
wrbu.si.edu/wrbu.html
(The Walter Reed Biosystematics Unit maintains the U.S. mosquito collection)
mosquito.org
(Home of the American Mosquito Control Association)
www.inhs.uiuc.edu
(The Illinois Natural History Survey, recorder of the state’s biological resources)
Source: “A Synopsis of the Mosquitoes of Illinois: Biological Notes No. 52, March 1965,” by Ross and Horsfall, Illinois Natural History Survey; the American Mosquito Control Association.
