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IX] at all events the females, hibernate in dark and sheltered places, to become active again on the return of warm weather. In this way the species is carried over the cold weather of winter, though there are

Fig. 27.—Anopheles maculipennis, Meig, larva, showing breathing position at surface of water. (After Howard, Bull. United States Dept. Agr.)

some species that hibernate in the larval stage and others in the egg. The duration of the life of the adult insect has not been definitely ascertained; it

Fig. 28.—Culex fatigans larva in breathing position at surface of water. (After Howard, Bull. United States Dept. Agr.)

is known that some species, if supplied with water and suitable food, can live for several months.

It is suggested that the mosquito tends to return to the particular pool in which she herself was