Xenidae

Definition

A family of twisted-winged insects in the order Strepsiptera, comprising approximately 13 genera and more than 120 described species. Members of Xenidae are obligate endoparasitoids, primarily of other insects, and exhibit the extreme sexual dimorphism characteristic of strepsipterans: females are legless, larviform, and remain within the host, while males are free-living with reduced forewings (halteres) and fan-shaped hindwings.

Etymology

Example

Xenidae species parasitize hosts in the orders Hemiptera and Orthoptera, with females typically protruding from between the host's abdominal segments while releasing first-instar larvae called triungulins.

Related Terms

• Strepsiptera
• Stylopidae
• triungulin
• endoparasitoid
• Hypermetamorphosis
• Sexual dimorphism

Usage Notes

Xenidae is one of several families within Strepsiptera; it can be distinguished from the larger family Stylopidae by host associations and details of male genitalia and wing venation. The family is sometimes referred to in older literature under different nomenclatural arrangements, though Xenidae remains the valid name.