Big-headed flies

Definition

A family of small, stout-bodied Diptera (Pipunculidae) distinguished by males having disproportionately enlarged compound eyes that meet broadly at the top of the head. Adults are agile predators that intercept other flies in mid-air; females are endoparasitoids, depositing eggs directly into the abdomen of living adult hosts, chiefly Auchenorrhyncha (leafhoppers, planthoppers, and treehoppers) and occasionally other Diptera. The family contains roughly 1,400 described species and is cosmopolitan in distribution.

Etymology

From the characteristic enlarged head of males, with eyes that occupy most of the head capsule.

Example

The big-headed fly Nephrocerus scutellatus targets adult froghoppers (Cercopidae), with larvae consuming the host from within before emerging through the abdomen to pupate in soil.

Synonyms

• Pipunculidae

Related Terms

• Diptera
• endoparasitoid
• Auchenorrhyncha
• leafhopper
• planthopper
• compound eye
• holometabolous
• Biological control

Usage Notes

The common name refers specifically to males; females have smaller, separated eyes and a more typical fly-like head. The family is sometimes called 'pipunculid flies' in technical literature. Distinguish from similar-looking acalyptrate families by the reduced wing venation and the male head morphology. Important in population regulation of planthopper pests in rice and other crops.