Hangingflies

Definition

A common name for insects of the family Bittacidae (order Mecoptera), predatory scorpionflies that hang from vegetation by their forelegs and capture prey with their raptorial hind legs. Unlike true flies (Diptera), they retain two pairs of wings and exhibit a distinctive perching posture that gives them their name. Males typically offer prey gifts to females during courtship, a behavior that has made them important study organisms for sexual selection research.

Etymology

From the characteristic behavior of hanging from twigs and leaves by the front legs while the body dangles beneath.

Example

Hangingflies in the genus Bittacus are often found in moist woodlands, where they suspend from understory vegetation to ambush small flies and moths.

Synonyms

• hanging scorpionflies

Related Terms

• Scorpionflies
• Mecoptera
• Bittacidae
• raptorial legs
• prey gift
• Panorpidae

Usage Notes

The term specifically refers to family Bittacidae within order Mecoptera, not to any fly that happens to hang. Do not confuse with hangingfly behavior in other groups (some empidid dance flies also hang, but are true Diptera). The family Cimbrophlebiidae, sometimes grouped with hangingflies, is extinct and known only from fossils.