Adults Culex restuans is a medium-sized brown mosquito, with adult female wing length ranging from 4 to 4.4mm. It is occasionally called the "white-dotted mosquito", referring to two white dots sometimes found on the dorsal scutum. This, however, is not a reliable character for identification because scales that constitute these spots can fall off and some adult mosquitoes eclose without these spots. Without these distinctive white dots, this species looks very similar to another medically important
Culex mosquito,
Cx pipiens. The coloration and number of erect scales on the dorsal area of the head, number of
setae on the upper
thoracic proepisternum, coloration of prepostnotal setae, coloration of setae found on the mid-lobe of the scutellum, and coloration of wing remigial setae were all found to be reliable characters for distinguishing these two species in their data set. They are worm-like in appearance, with distinct brush-like mouthparts, a round thorax, abdominal segments with distinct lateral tufts of setae, and a siphon at the end of their abdomen which they use to breathe.
Cx restuans larvae can be recognized from other species of
Culex from at least three long, individual setae on their siphon that are irregularly placed; siphon setae of other
Culex species are found in groups or tufts. == Natural history ==