Developmental Cycle

Adults possess a long proboscis projecting forwards from the head, have scales on the wing veins and a fringe of scales along the posterior margin of the wing. Their wing venation is characteristic with the second, fourth and fifth longitudinal veins being branched (Goma, 1966).

Males and females can be differentiated by the form of the antennae. In males they are very plumose, while in females they only have a few short hairs. In most others than Anopheles species the maxillary palps in the female are very short in contrast to the male where they are longer than the proboscis. In both sexes of Anopheles the maxillary palps are long, but clubbed in the male.

They are usually active during the twilight hours or at night, or in dense shade: many spend the day in hollow trees, under culverts, or in similar resting places. Some overwinter in such places.

Only the females are blood-sucking, males and occasionally also females feed on naturally occurring sugary secretions including nectar.

Blood digestion is temperature-dependent and takes 2-3 days in tropical areas, respectively 1-2 weeks in temperate climates. After digestion the female is ready to lay eggs, which means it is gravid. The gonotrophic cycle is repeated several times during a mosquito's life time. Some species may show alterations of this scheme (e.g. multiple blood meals before becoming gravid in Aedes aegypti).

Life Expectancy

Life expectancy is depending on climatic conditions. In tropical climates females live on average 1-2 weeks, in temperate zones they might survive 1-2 months or even remain in hibernation for up to 9 months. Males usually have a much shorter life.

Autogeny

Autogeny i.e. oviposition without a preceding bloodmeal is sometimes observed in mosquitoes especially in the first ovarian cycle. But generally so-called anautogeny occurs.

   

Further information

• Goma LKH: The mosquito. 1966, Hutchinson Tropical Monographs, Hutchinson & Co. (Publishers) LTD, London