Cochliomyia spp

From Cow
C. macellaria blowfly

Cochliomyia spp (New World Screwworm fly) are a parasitic blowfly which causes myiasis in cattle in the Americas.

C. macellaria is found throughout northern South America, Central America, Caribbean Islands, United States, and southern Canada. C. hominivorax has been eradicated from the U.S. and Mexico but still prevalent in South America[1][2].

Cattle are an intermediate host for this fly and secondary skin damage may result in lesions which can become infected[3].

Doramectin[4], dicyclanil[5] and Fipronil[6] have proven effective at minimising disease caused by this parasite when applied topically to cattle.


  1. Bermúdez SE et al (2007) Incidence of myiasis in Panama during the eradication of Cochliomyia hominivorax (Coquerel 1858, Diptera: Calliphoridae) (2002-2005). Mem Inst Oswaldo Cruz 102(6):675-679
  2. Phillips PL et al (2004) Seasonal and spatial distributions of adult screwworms (Diptera: Calliphoridae) in the Panama Canal area, Republic of Panama. J Med Entomol 41(1):121-129
  3. Bowman DD (2006) Successful and currently ongoing parasite eradication programs. Vet Parasitol 139(4):293-307
  4. Anziani OS et al (2000) Persistent activity of doramectin and ivermectin in the prevention of cutaneous myiasis in cattle experimentally infested with Cochliomyia hominivorax. Vet Parasitol 87(2-3):243-247
  5. Anziani OS et al (1998) Efficacy of dicyclanil in the prevention of screwworm infestation (Cochliomyia hominivorax) in cattle castration wounds. Vet Parasitol 76(3):229-232
  6. Lima WS et al (2004) Evaluation of the prophylactic effect and curative efficacy of fipronil 1% pour on (Topline) on post-castration scrotal myiasis caused by Cochliomyia hominivorax in cattle. Vet Parasitol 125(3-4):373-377