Premium Services    Mosquito (Culex pipiens) Unsigned wood-engraving From: Louis Figuier, The Insect World: being a popular account of the orders of insects…. Trans. of Les insects. New ed., rev. and corr. by P. Martin Duncan (London, New York, [1872]) NYPL, General Research Division

The metamorphosis of the common mosquito is illustrated in this popular study by Louis Figuier (1819–1894). At bottom is the aquatic larva, or "wriggler" (right), and the pupal phase, or "tumbler"; at center the emerging insect; and at top an adult male, who lacks the piercing mouthparts of the female on the right, used to obtain mammalian and avian blood needed for egg production.

Mosquitoes are not only annoying pests but are principal transmitters of the encephalitis-causing West Nile disease virus, which first appeared in New York City in 1999, killing seven people and sickening many others. Since then, outbreaks have increased: the summer of 2002 saw a sharp rise in confirmed and suspected cases of West Nile fever in 38 states.