Female biting midge (Culicoides sonorensis). Biting midges are small flies with painful bites. The females suck blood from vertebrates, and are major pests in late summer. This species is also a vector of bluetongue disease, a condition which causes cyanosis in the tongues of ruminants. This midge is feeding on blood from an artificial membrane used in the mass rearing of insects. Magnification: x30 when printed 10 centimetres across.