Viv Wilson sent me a photograph of an Asilidae that
are part of the robber fly family, also called assassin flies, that h took in
his garden in Tabuk recently. He has kindly allowed me to use the photo on my
website and it is reproduced below. 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. There are over 7000 described
species. And in general attack 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. The fly attacks
its prey by stabbing it with its short, strong proboscis injecting the victim
with saliva containing neurotoxic and proteolytic enzymes which very rapidly
paralyze the victim. Asilidae generally occur in habitats that are open, sunny,
and dry, even arid. Asilidae occur in all zoogeographical regions except
Antarctica, however, the highest levels of biodiversity are in warm climates
with arid or semi-arid regions tending to have the greatest variety of species.
