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 larvæ and pupæ, called wigglers, are aquatic.
Any one of many small, delicate, long-legged flies of the Chironomus, and allied genera, which do not bite. Their larvæ are usually aquatic.
A very small fly, abundant in many parts of the United States and Canada, noted for the irritating quality of its bite.