T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Fly (Robber) Family: Asilidae

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Suborder: Brachycera
Infraorder: Asilomorpha
Superfamily: Asiloidea
Family: Asilidae
Species: There are over 7000 described species.

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.

Robber flies have stout, spiny legs and they have three simple eyes (ocelli) in a characteristic depression on the top of their head between their two large compound eyes. They also have a usually dense moustache of stiff bristles on the face; this is called the mystax.. The mystax has been suggested to afford some protection for the head and face when the flies deal with struggling prey; various Asilidae prey on formidable species including stinging Hymenoptera, powerful grasshoppers, dragonflies and even other Asilidae, in fact practically anything of a suitable size. In general the family attacks a very wide range of prey, including other flies, beetles, butterflies and moths, various bees, ants, dragon and damselflies, ichneumon wasps, grasshoppers, and some spiders.