Food Preference of Drosophilid Flies in Domestic and Forest Areas of Central Japan

Food preference was studied for drosophilid flies in domestic and forest areas of central Japan using artificially prepared resources (fruits, flowers, leaves, stems and mushrooms). The similarity of food preference was high among species occurring in domestic areas, especially among Drosophila melanogaster, D. simulans and D. lutescens and between D. auraria and D. immigrans. On the other hand, species occurring in forests usually differed in food preference from each other ; D. immigrans and D. lutescens preferred succulent fruits ; D. rufa used a variety of resources except for mushrooms ; D. bizonata preferred mushrooms ; D. sternopleuralis used a variety of substrates except for succulent fruits ; Scaptodrosophila coracina used a variety of substrates. This difference is assumed to play an important role in the maintenance of their coexistence. The rate of parasitism by wasps was generally high in larvae feeding on fruits and flowers, but low in those feeding on stems of Sasaella ramosa.