The genus Colletes (plasterer bees) is a large group of ground-nesting bees of the family Colletidae. They occur primarily in the Northern Hemisphere. They tend to be solitary, but sometimes nest close together in aggregations. Species in the genus build cells in underground nests that are lined with a cellophane-like plastic secretion, a true polyester, earning them the nickname polyester bees.
The Asilidae are the robber fly family, also called assassin flies. They are powerfully built, bristly flies with a short, stout proboscis enclosing the sharp, sucking hypopharynx. The name "robber flies" reflects their notoriously aggressive predatory habits; they feed mainly or exclusively on other insects and, as a rule, they wait in ambush and catch their prey in flight.
