CAN BE DONE ABOUT ALL THE MOSQUITOES?
May 24, 2009
Q: We began
having mosquitoes in our backyard this year about a month earlier than
usual. What can we do to reduce the number of or even eliminate these
were out earlier in some regions because we had more winter and early
spring rains than in recent years, when many areas suffered from drought
conditions. Rains followed by warmer than normal temperatures on some
days created ideal conditions for many species of mosquitoes to complete
their life cycle and reach the blood sucking stage we all despise.
3,500 species of mosquitoes exist, and like many other groups of animals
and plants, the highest diversity is in the tropics. But the temperate
zone where we live has its share of species. Also like other organisms
with many species, mosquitoes differ considerably in their natural history,
including one group that does not even bite people. The basic life cycle
of a mosquito, like that of flies, grasshoppers, and many other insects,
starts with the egg, which becomes a larva, which develops into a pupa
before becoming an adult. Mosquito larvae and pupae are the "wigglers"
(also called "wrigglers") seen flipping around in shallow standing
One of the
basic steps in reducing the number of mosquitoes around a house is to
eliminate standing water. The problem is that amounts as negligible as
that collected in a dead magnolia leaf, an un-emptied rain gauge, or a
low spot in a house gutter can become a mosquito nursery where eggs are
laid and larvae and pupae thrive. Old tires and tree holes can also collect
water and are actually preferred egg-laying sites for some mosquitoes.
Some kinds of mosquitoes even lay their eggs on dry soil in depressions
that later fill with water, stimulating the eggs to hatch. Sprinkler systems
that keep grass and shrubs looking nice often provide all the water some
mosquitoes need to start the cycle.
stages last for a few days to a week or more, depending on the species
and on the ambient temperature. Adult mosquitoes can live for days or
weeks. Only the females suck blood, as part of the reproductive cycle.
The blood is used to provide nourishment to the eggs while they are in
the female's body. When one batch of eggs is laid, she is ready for another
blood meal to get the next batch ready. Male mosquitoes, benign creatures
that have no interest in humans, feed on nectar.
to eliminate mosquito problems in many ways, including neighborhood mosquito
trucks, backyard mosquito traps, handheld mosquito foggers, and the numerous
insect repellents on the market. The strategy of one of my daughters is
to stand close to her husband when mosquitoes are around. He apparently
attracts all of them, and they no longer find her as palatable. As a general
rule, mosquitoes are attracted to warm body temperatures, which we all
have, and carbon dioxide, which we all exhale. I know two people whose
body temperature runs about a degree below normal, and invariably they
are not bitten by mosquitoes while others around them are.
tactic in the war against mosquitoes, besides swatting the life out of
them when they land on your arm, is to set up a mosquito decoy site. Put
a bowl or glass of water somewhere in your yard, such as on a deck or
porch, and check it daily. If wrigglers are present, one of the blood-sucking
mosquitoes laid her eggs a few days earlier. Give the wrigglers a day
or so before you pour the water out on dry ground to kill them. Then refill
the container for the next round. You can enjoy knowing you have scored
a minor victory over one female mosquito and her insidious progeny. Also,
the decoy lets you know that mosquitoes have recently laid their eggs
so the time has come to search for other standing water around the house.
Incidentally, a dab of toothpaste is a quick and effective way to stop
the itching from bites by mosquitoes whose mothers don't fall for the
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