ATTRACTION OF A KLEPTOPARASITIC SPHAEROCERID FLY (NORRBOMIA-FRIGIPENNIS) TO DUNG BEETLES (PHANAEUS SPP AND CANTHON SP)

Norrbomia frigipennis (Diptera: Sphaeroceridae) is phoretic on dung-fe eding scarab beetles (Coleoptera: Scarabaeidae). In this study we inve stigate the attractiveness of three beetle species, Phanaeus ignius, P . vindex, and Canthon pilularis, to the fly. Stationary, moving-dead, and live beetles were used. More flies were attracted to Phanaeus. How ever, this attractiveness may be due to the larger average size of Pha naeus. A preference for larger individuals was found within Phanaeus, though not within C. pilularis. Flies mounted beetles on the thorax an d the elytra at similar rates. Phanaeus males that possesed horns did not attract more flies than did hornless ones, and there was no effect of host sex on attractiveness. In horned Phanaeus, about 11-16% of th e flies mounting those beetles landed on the hem.