Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, July 4, 1993 TAG: 9309010293
SECTION: EXTRA PAGE: 7 EDITION: METRO
SOURCE: Patricia Held
DATELINE: LENGTH: Medium
There are more than 2,000 kinds of mosquitoes, and they are found everywhere from the northern tip of Alaska to the southern tip of Brazil. About 100 types inhabit the United States. During the mosquito season 10 trillion will spread across the county. (I've read that that is enough mosquitoes to fill the Grand Canyon.)
The mosquito is a member of the fly family, but that is not much to boast about. In general, who likes flies? They are considered dirty and pesky, with the mosquitoes ranking among the lowest of the family members.
But a few mosquito facts may help this insect's popularity.
If it were not for the mosquito, man would not have much of an opportunity to contribute to the food chain. As we all know, mosquitoes will feed on our blood. They in turn are eaten by birds and other small animals, who are, in turn eaten by much bigger animals. We form an important link in this chain.
In their immature form mosquito larvae eat bacteria in pools of water. They play an important role in keeping our waters clean.
Without water the mosquito population would disappear. Mosquitoes breed in ponds and pools of slow-moving water. Larvae are not found on open lakes or swift running streams.
The life history of the mosquito is not simple. Right now is their egg-laying season. Adult females land on the water's surface and lay several hundred eggs, then manipulate them into a raft. Known as ``wrigglers'' because of their manner of moving, mosquito larvae hang from a film covering the surface of the quiet water. They take in air by means of a tube that is located at the tail end of their bodies. Young mosquitoes are nourished by tiny plant and animal matter that floats on the water's surface.
Most mosquito larvae develop directly in the water. The length of time needed for the immature mosquitoes to develop into adults ranges from a few days to several months. Each species has its own special nursery site. Those that lay their eggs in shallow rain puddles usually hatch within three or four days, while other species that choose more permanent wet areas may take three months to mature.
Once mosquitoes reach adulthood, their diets change. Full-grown mosquitoes feed primarily on plant juices, and with a few exceptions the female also needs at least one meal of blood for her eggs to develop properly. It is not quite understood why some mosquitoes need blood. Some researchers think that the blood provides extra nutrients to keep the insects healthy. One of the few mosquitoes that does not need blood (but still seems to enjoy it) is the common house mosquito.
Only female mosquitoes bite. So, before swatting, make sure it is a female mosquito. They are the ones that make the buzzing noise that we are all so familiar with. Also, the females lack the elaborate and feathery antennae of the males.
Unfortunately there is not much we can do to escape these flying pests. Insect repellents sometimes help, and it is said that we do develop some kind of immunity to local mosquitoes.
Common-sense rules can fend them off to some degree. Do not wear bright colors or sweet smells. Avoid sweating, heavy breathing - and keep healthy! Studies indicate that mosquitoes tend to dine on sickly people and those who have just completed strenuous activity and are sweating and breathing hard.
\ Patricia Held will respond to readers' questions on the plant and animal wildlife in the region. Mail inquiries to Patricia Held, P.O. Box 65, Goode, Va. 24556.
\ Patricia Held is a Bedford County free-lance writer specializing in natural history.
by CNB