Description Culex nigripalpus is a medium-sized mosquito. The proboscis is dark and the palpi short. The scutum is brown with fine dark bronze to brown scales. The pleura has few or no scales. Narrow white basal bands are occasionally present on the dorsal surface of some abdominal segments.
Legs are dark with reflective bronze to metallic blue-green scales.
The posterior surface of the femora and tibiae are pale. In general, this is a dark brown, nondescript species with no obvious distinguishing characteristics, making field identification to the species level extremely difficult. Eggs of this species have been reported in virtually every type of aquatic habitat. However, the species is best described as a flood water Culex . Females prefer to lay eggs in freshly flooded roadside ditches and agricultural furrows, habitats that flood infrequently and, once flooded, remain wet for 10 to 14 days before drying down completely.