Chrysomya bezziana

Chrysomya bezziana - FAO/IAEA, Wikimedia Commons

Also known as:

Old world screwworm

Scientific Classification

Class	Insecta
Order	Diptera
Family	Calliphoridae

Hosts

Cattle, sheep, dogs and occasionally humans.

Identification

C. bezziana is a blue/green fly, with 4 longitudinal black stripes, and around 8-10mm in length. They are similar to Calliphora spp.

Life Cycle

C. bezziana is an obligate agent of myiasis. The female lays eggs in fresh open wounds or body orifices. Eggs then hatch and the larvae begin to penetrate the skin. The larvae then mature and begin to pupate, before becoming fully reproductive adults.

The complete life cycle from egg to adult is 2-3 weeks.

Clinical

Pathogenesis

• Spiracles are exposed as larvae feed which expands the wound
  • Creates a foul smelling lesion

• Cause irritation and pyrexia

Control

• In the USA
  • Mass eradication through the release of sterile males
  • Currently only persists where flies have migrated across the Mexican border

• In Africa
  • Introduced into Libya through the importation of infested livestock
  • Sterile males released
  • Eradication occurred in 1991