Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Subfamily Gasterophilinae - Stomach Bot Flies

Gasterophilus intestinalis larvae - Gasterophilus intestinalis horse bot fly - Gasterophilus intestinalis - female horse bot fly - Gasterophilus intestinalis - female horse bot fly - Gasterophilus intestinalis - female horse bot fly - Gasterophilus intestinalis - female Bot fly? - Gasterophilus intestinalis - female Bot fly? - Gasterophilus intestinalis - female Gasterophilus intestinalis? - Gasterophilus intestinalis
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Diptera (Flies)
No Taxon (Calyptratae)
Superfamily Oestroidea
Family Oestridae (Bot Flies)
Subfamily Gasterophilinae (Stomach Bot Flies)
Other Common Names
Horse Bots
Numbers
4 spp. in a single genus in our area(1), 17 spp. (of which 9 Gasterophilus) in 5 genera worldwide(2)(3)
Range
Gasterophilus spp. occur worldwide: three of our spp. are cosmopolitan, and one introduced (recorded in IL)(1), other genera are palaeotropical(2)
Food
Gasterophilus larvae develop in horse intestines(1), larvae of the exotic genera parasitize rhinos (1 genus, 3 spp.) and elephants (3 genera, 5 spp.)(2)
Works Cited
1.American Insects: A Handbook of the Insects of America North of Mexico
Ross H. Arnett. 2000. CRC Press.
2.Medical and Veterinary Entomology
Gary Mullen, Lance Durden. 2002. Academic Press.
3.Phylogeny and evolution of bot flies
T. Pape. 2006. In: The oestrid flies: Biology, host–parasite relationships, impact and management (D.D. Colwell et al., eds): 20-50.