- Any one of various species of gnats of the genus Culex
and allied genera. The females have a proboscis containing, within the
sheathlike labium, six fine, sharp, needlelike organs with which they
puncture the skin of man and animals to suck the blood. These bites,
when numerous, cause, in many persons, considerable irritation and
swelling, with some pain. The larvae and pupae, called wigglers, are
aquatic.