BALLOON FLY

also called Small-headed Fly, any insect of the family Acroceridae (order Diptera), so named because of its swollen abdomen. It is also characterized by an extremely small head and a humped back. Those adults that have a slender proboscis (feeding organ) feed from flowers; those lacking a proboscis probably do not feed in their adult stage. Their larvae are internal parasites of spiders.