Asilidae, in the robber fly family, are 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.
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 and soon digest the insides; the fly then sucks the liquefied material through the proboscis.
However, unlike bees and wasps, Robber Flies do not sting, and the "stinger" on this Robber Fly is actually a harmless ovipositor that she uses for laying eggs. Although they don't attack or bother humans, Robber Flies can bite quite painfully, so do not capture or pick up these flies with your bare hands
Top photograph by Julio Hernandez, second photo by Jorge Castellanos
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