After being ejected by the host, they pupate in soil (2 to 3 weeks) before emerging as a sexually-mature but non-feeding adult, which must quickly find a mate, since their lifespan is short.

These creatures are as large as the largest grubs; they grow all together in a cluster, and they are usually about twenty in number.Species found in the United States include C. apicata, C. jellisoni, C. phobifer, C. pratti, and C.

[2] It was reported for many years that Cephenemyia was the fastest of all flying insects, cited by The New York Times[5] and Guinness Book of World Records as traveling at speeds of over 800 miles per hour (1,300 km/h).

[7] In 1938 Irving Langmuir, recipient of the 1932 Nobel Prize in Chemistry, examined the claim in detail and refuted the estimate.

[8] Among his specific criticisms were: Using the original report as a basis, Langmuir estimated the deer botfly's true speed at a more plausible 25 mph (40 km/h).