Corrected misidentification of first instars of the bot flies Cephenemyia apicata and C . jellisoni , with a review of the biology and life history of both species

First instars obtained from the uteri of host‐seeking females, and compared with previously published descriptions of larvae collected from Columbian black‐tailed deer ( Odocoileus hemionus columbianus ), revealed that larvae described as Cephenemyia apicata Bennett & Sabrosky (Diptera: Oestridae) actually are C. jellisoni Townsend. Several new characters are added to supplement the original descriptions of the first instars of these species. Collections of all larvae from deer autopsied during different months established that the first instars of C. apicata undergo a long obligate period of development and growth in the bronchi before molting and migrating to the retropharyngeal pouches of deer. This is the first study to document an obligatory lung phase in the life history of a species of Cephenemyia . The lung phase of C. apicata is compared with that described for Pharyngomyia picta (Meigen) (Diptera: Oestridae) in European red deer. A literature review found that for all Cephenemyia species studied, as well as for P . picta , a 6–8 month period of development as first instars during the fall/winter months ensures that pupal development and eclosion of adults will occur during periods of favourable external environmental conditions.