Crane Fly – Tipula dorsimacula
Live adult female fly photographed at Winfield IL USA April 23, 2004. Size: 25mm not including legs. I believe this giant crane fly had recently been laying eggs when I stumbled upon it – the tip of the abdomen is wet as if it had been in the water or mud.
Thanks to Dr. Chen Young of Carnegie Museum of Natural History for identification of this specimen.
The small, bulbous structures are called halteres. They are used for balance and vibration damping during flight. All true flies have these organs; they evolved from the second set of wings present in most other insects. True flies are the only insects that only have two wings. (Diptera = 2 wings)
Flies of North America – Order Diptera. Flies are prevalent in virtually all habitats, with over 16,000 species in North America.