The Flies

Living within the pitchers of almost all the species of pitcher plants in the southeastern United States (Sarracenia spp.) are larvae of some extremely specialized flesh flies (Diptera: Sarcophagidae).  Flesh flies may have a fairly plain external appearance but they do exhibit a great diversity in their life histories.  Most sarcophagid species are parasitoids of other invertebrates, or live as carrion or dung breeders.

The sarcophagid genus Fletcherimyia has 5 described species, all of which develop only within the pitchers of pitcher plants.   There is also one species within the genus Sarcophaga (pictured above) that also spends its larval portion of its life cycle within pitcher plant pitchers.  The larvae feed on the decaying insects trapped by the plant. While Sarcophaga sarraceniae appears to be a generalist, being reared from a wide variety of Sarracenia species, many of the Fletcherimyia are much more intimately associated with few (often one) species of pitcher plant.  Dr. Greg Dahlem is nearing completion of a systematic revision of the flesh flies associated with pitcher plants.

Male flesh flies have complex, species-specific genitalia and the shape of the genitalia is the main characteristic used for identification of these flies. As such, they can serve as excellent subjects for investigations within the fields of sexual selection and evolution.  Jennifer Gabbard (an NKU undergraduate student) is investigating aspects of sexual selection and genital evolution using the species Fletcherimyia jonesi and F. rileyi as study organisms.

During our study in the summer of 2000, we have collected sarcophagid flies from a variety of pitcher plant bogs in the southeastern U.S.  The following is a list of the Sarcophagidae collected on our late May/early June collecting trip.  Many of these sites were in or near land where cattle grazed, and this is indicated by the number of dung breeding sarcophagids collected at several of these sites (e.g. Oxysarcodexia & Ravinia spp.).  In addition to these specimens, larvae were collected from pitchers. Tonya Foree (an NKU undergraduate student) is in the process of rearing them to adults for species identification and association with the particular host Sarracenia species.
 
 

Laboratory set-up for rearing flesh flies from larvae collected in the field	3rd instar larva of S. sarraceniae
	Puparium of S. sarraceniae