Blackflies have broad wings with all the obvious veins in the anterior part of the wing.
The family is widely distributed, the adults often occurring in such large numbers as to make them a nuisance. They are most abundant in north temperate and subarctic regions. Classification Blackflies are in family Simuliidae, order Diptera, class Insecta, phylum Arthropoda. They are found on stones, reeds, mayfly larvae, and other aquatic forms. The pupae usually rest in a tent of silk in similar situations to the larvae.