. moistened, however, they may remain dormant for weeks or even months. When immersed in water they promptly hatch. Under most favorable conditions the wigglers (fig. 4) develop in 6 to 8 days and change into the less active tumbler or pupa stage (fig. 5), from which the adult insect (title page illustra- tion and fig. 2) emerges about 2 days later. The complete develop- ment from egg to adult mosquito is, therefore, 9% to 12 days, or longer in cooler weather or under less favorable conditions. The house mosquitoes have a similar developmental period, but they differ markedly from the yellow-f
. moistened, however, they may remain dormant for weeks or even months. When immersed in water they promptly hatch. Under most favorable conditions the wigglers (fig. 4) develop in 6 to 8 days and change into the less active tumbler or pupa stage (fig. 5), from which the adult insect (title page illustra- tion and fig. 2) emerges about 2 days later. The complete develop- ment from egg to adult mosquito is, therefore, 9% to 12 days, or longer in cooler weather or under less favorable conditions. The house mosquitoes have a similar developmental period, but they differ markedly from the yellow-fever mosquito in the egg stage. The eggs are laid in boat-shaped masses or rafts (fig. 6) directly on the surface of the water and, if dried, soon lose their ability to hatch. Biting Habits Figure mosquito. Egg of the yellow-fever About 100 times natural
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Keywords: ., bookcentury1900, bookpublisherwashingtondcusdeptofagriculture
