Oestridae

Oestridae is a family of flies within the order Diptera, commonly referred to as bot flies or botworms. Members are largely parasitic as larvae, developing in mammals and causing myiasis in livestock, wildlife, and occasionally humans. The group is cosmopolitan, with species adapted to a variety of hosts and tissues, from nasal passages to subcutaneous tissue and the stomach.

Adults generally have short lifespans and, in many species, do not feed. The females lay eggs or first-instar larvae on the body of a suitable host or on an intermediate vector. Larvae enter the host by inhalation, ingestion, skin penetration, or through mucous membranes, depending on species. They migrate to their preferred site, grow through several instars, and eventually leave to pupate in the environment.

Notable oestrids include Oestrus (nasal bot flies of sheep and goats, notably Oestrus ovis); Hypoderma (warble flies of cattle); Gasterophilus (stomach bots of horses); Cephenemyia and other nasal bots of deer; Cuterebra (subcutaneous parasites of rodents and lagomorphs); and Dermatobia (human botfly).

Infestations can cause irritation, tissue damage, reduced growth or productivity in livestock, secondary infections, and, in some cases, severe illness. In humans, botfly larvae can cause dermal myiasis. Control relies on veterinary management, timely animal care, proper sanitation, physical barriers to prevent egg deposition, and targeted insecticides or repellents when appropriate.