Epigeal Arthropods as Predators of Mature Larvae and Pupae of the Apple Maggot (Diptera: Tephritidae)

Numerous species of epigeal arthropods collected from apple orchards in southern Ontario were predaceous on larvae and pupae of the apple maggot, Rhagoletis pomonella (Walsh). However, few species fed extensively on dipterous prey and the numbers of individuals that were serologically positive with antiserum to R. pomonella were generally low. The ground beetles Amara aenea DeGeer, Harpalus aeneus F., and Pterostichus melanarius Illiger; the staphylinids, Philonthus spp.; the ants, Formica fusca L. and Myrmica sp.; and the spider, Trochosa terricola Thorell, appeared to be the most frequent predators of R. pomonella .