They react to slight disturbances of the water by tumbling to deeper water and, after a
few moments, rising to the surface with Iittle or no effort.
g. When the adult is ready to emerge from the pupa, the skin of the pupa splits
along the upper surface and the adult pulls itself up and out of the floating skin on which
it then rests untiI ready to fly. Both the male and female adult mosquitoes can feed on
flower and plant juices, but the females of most species suck blood and attack humans
and other animals. The adult mosquitoes exhibit a great variety of habits and
capabiIities with respect to flight range, biting preferences, disease transmission, and
abundance.
h. Three common genera of mosquitoes that transmit disease are Anopheles,
Aedes, and Culex, each of which consists of many species.
(1) The Anopheles wiII breed in almost any type of water, but prefer
vegetated, permanent pools. The larvae Iie parallel to the surface of the water, whiIe
the adults rest and feed with the body at an angle of 45 to the surface on which they
are resting (see figure 1-9). Anopheles mosquitoes bite primariIy during the period from
dusk to dawn. They may bite during the daylight hours in an area that is heaviIy shaded
or in a room that is dark. About 80 of the 350 species of Anopheles mosquitoes
transmit malaria. A very common mosquito in the southern part of the US is Anopheles
quadr imaculatus that was a very important malaria vector in the US before the 1940's.
Although this species is stiII present in the US, it is only a potential vector because the
human reservoirs no longer occur in this country.
Figure 1-9. Typical resting positions of Anopheles mosquitoes in their
larval and adult stages.
(2) Aedes mosquitoes are one of the most important vectors of disease;
based on the variety of diseases they can transmit. They breed in temporary water that
may be fresh, stagnant, or brackish. Aedes aegvpti, the yellow fever mosquito, larvae
can be commonly found in discarded tires, tin cans, flower vases, and other artificial
containers. The larvae are equipped with an air tube or siphon, and when they are
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