Photo Courtesy of Jason Williams

Photo Courtesy of Jason Williams

Medium size

Proboscis: black

Palpi: short, dark

Head: occiput with curved silver-white lanceolate scales and white erect forked scales on median area with broad appressed white scales laterally. Tori brown with fine dark setae on iner surface.

Thorax: Integument of scutum brown to black. Scutum with wide median stripe of narrow dark-brown scales. The stripe becomes much broader distally and covers most of posterior half of the scutum. Sides with white lanceolate scales; prescutellar space bordered with white scales. Scutum with dark-brown setae on the lobes; a patch of white scales on the middle lobe posterior pronotum clothed with broad appressed silver-white scales. Pleura with dense, well-defined patches of broad closely appressed silver-white scales.

Abdomen: Tergites blue-black-scaled, with basal patches of white scales laterally. Venter white-scaled, with apices of the terminal segments black.

Legs: Hind femur yellowish white on basal half to two-thirds, dark apically; front and middle femora black, posterior surface pale; knee spots white. Tibiae and tarsi dark.

Wings: length 3.5 to 4.0 mm scales dark, narrow.

Bionomics: This species is widely distributed in North America. It is a treehole and artificial container breeder …most of time in or near edge of wooded area. It overwinters as an egg …several broods per year …eggs are laid just above the water surface in treehole and containers. Larvae found May to September. They fly and bite during daylight hours in shade or wooded area. They are persistent biters. It is the main vector of LaCrosse encephalitis in the western part of Virginia …they feed primarily on squirrels and chipmunks. Flight range …1/2 to 1 mile.