Comparing growth of pork- and venison-reared Phormia regina (Diptera: Calliphoridae) for the application of forensic entomology to wildlife poaching.

Laboratory rearing of Phormia regina Meigen larvae on pork and venison was conducted as part of a study to determine whether forensic entomology approaches can be used in wildlife poaching investigations. Larvae were reared at 30 degrees C, 75% relative humidity, and a photoperiod of 14:10 (L:D) h on pork or venison diets, and samples were collected every 8 h until >90% of the maggots reached the third-instar wandering or prepupal stage. Significant differences were found in the distribution of lengths of the third instar and combined instars for maggots reared on the two different meat sources. Maggots reared on venison reached the prepupal wandering stage significantly faster (approximately 6 h) compared with maggots on the pork diet. Mean adult weight and wing length of venison-reared flies were significantly greater than for flies reared on pork. The lower crude fat content of venison appears to make this meat source a more suitable medium than pork for larvae of P. regina. The difference in growth rate could introduce error into PMImin estimations from third-instar maggots in deer poaching cases if estimates are based on data from studies in which maggots were reared on pork.

Effect of tannins on galliform cecal partitioning.

Winter diets of ruffed grouse (Bonasa umbellus) and other galliformes are high in tannins. We fed quebracho, a condensed tannin, to ruffed grouse and found no effect on dry matter intake or body mass at levels up to 6% of the diet. However, a high-fiber diet with 8% quebracho resulted in reduced dry matter intake and body mass loss. Grouse could not tolerate a diet with 8% tannic acid, a hydrolyzable tannin, which caused a large reduction in dry matter intake and body mass. Northern bobwhite (Colinus virginianus) and ruffed grouse responded to dietary quebracho tannin by increasing the proportion of digesta that was excreted from the ceca. In the northern bobwhite, 59%-76% of the tannin recovered from the feces was in cecal feces. There was no difference in average passage rates of liquid and fiber digesta, although variation was high in tannin-fed birds. The role of the ceca in handling tannin requires further investigation.