Nematode parasites of insects

Definition

Nematodes (roundworms) that complete at least part of their life cycle within or upon insect hosts, typically causing disease or mortality. These associations range from obligate parasitism to facultative entomopathogenesis. Insect-parasitic nematodes are deployed widely in biological control, particularly against soil-dwelling pest larvae.

Etymology

Greek nema (thread) + ode (like); Latin parasitus (one who eats at another's table)

Example

Entomopathogenic nematodes in the families Steinernematidae and Heterorhabditidae carry symbiotic bacteria (Xenorhabdus or Photorhabdus) that they release into host insects after penetrating through natural openings; the bacteria multiply and kill the host within 24–48 hours, providing nutrients for nematode reproduction.

Synonyms

• entomopathogenic nematodes
• insect-parasitic nematodes

Related Terms

• entomopathogen
• Biological control
• Steinernematidae
• Heterorhabditidae
• mermithid
• Parasitoid
• Integrated Pest Management

Usage Notes

The term is sometimes used interchangeably with 'entomopathogenic nematodes,' though strictly speaking not all insect-parasitic nematodes are entomopathogenic (some, like mermithids, are parasitic but not necessarily lethal). Specialists distinguish between 'parasitic' (surviving host death) and 'pathogenic' (causing host death) relationships. The abbreviation EPN is common in applied entomology literature.