a handbook of the mosquitoes of north america - Systematic Catalog ...

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BIOLOGY 33
ing before the ice has melted. In central New York, the larvae
reach maturity in April and early May. According to the
season, the adults emerge from the middle of April to the
middle of May. This species sometimes appears in immense
swarms and as they live throughout the summer, they are
serious pests not only in woodlands, along river courses, lake
resorts, etc., but they travel considerable distances invading vil-
lages, towns and even large cities. How long the adults live,
we do not know, though they are present each year till the
middle of September.
EGG-LAYING HABITS OF MOSQUITOES
The egg-laying habits of mosquitoes vary widely. All our
Cz~?ex species deposit their eggs in rafts (Fig. 13, a) on the
surface or near the surface of water. This is also true for the
species of Theobaldia (Fig. 13, b), Taeniorhynchus and
Urarvzo talenia, Asop1zeZe.s species lay their eggs singly or in
small loose groups upon the surface of the water. The eggs
lie on their sides and float by means of a lateral expansion
which is made up of small chambers containing air (Fig. 13,
d, e, f, and g) . The great majority of the northern species
belonging to the genus Andes do not lay their eggs on or in
water but on the ground at the bottom of dried out pools,
ponds, marshes, swamps, etc. (Fig. 13, c). These eggs are laid
during the summer and remain till the following spring. Sub-
mergence in water during the same season will not cause them
to hatch. Thus these species usually appear in one great an-
nual brood, the adults emerging in early or late spring. All
our Aedes species are not single brooded. Aedes aegypti (the
yellow fever mosquito) is a domesticated species living at all
times in close proximity to human habitations. It breeds con-
tinuously throughout the year if water can be found and the
temperatures do not remain below 68” F. This species lays
its eggs (Fig. 13, c.) singly either on or just above the sur-
face of the wa.ter. Aedes vexam, a very troublesome species
in many sections of North America, appears to have very dif-