1. Wings absent, abdomen thick & round posteriorly, antennae do Not extend from the head, usually specific to sheep .......... Melophagus ovinus (Sheep Ked)
2. One pair of wings present ........ Go to: 3 & 4

3. Moderate-size hairy flies (resembling bees); lacking mouthparts .......... Gastrophilus sp. (Bot Fly)
4. Small to large flies possessing mouth parts .......... Go to: 5 & 6

5. Small, black gnat-like flies with humped-backs and short straight antennae .......... Simulium sp. (Black Fly)
6. Flies larger than gnat size .......... Go to: 7 & 8

7. Fly with metallic green or blue body .......... Phormia sp. (Bottle or Blow Fly)
8. Flies without a metallic body .......... Go to: 9 & 10

9. Flies in similar appearance (gray bodies) and size (or slightly smaller) to a common house fly, with short lobed antennae .......... Go to: 11 & 12
10. Flies in larger than a common house fly with long horn-like antennae and blade-like mouth partso a common house fly .......... Go to: 13 & 14

11. Flies with sponging mouth parts .......... Musca domestica (House fly) or Musca autumnalis (Face Fly)
12. Flies with pointed, piercing mouth parts .......... Stomoxys sp. (Stable fly) or Haematobia sp. (Horn Fly)

13. Medium size flies with yellow bodies and brown bands on the wings .......... Chrysops sp. (Deer or Dog Fly)
14. Medium to very large flies, bodies from grey to green to black, wings without brown bands .......... Tabanus sp. (Horse fly)