Overwintering and Aestivation Sites of Coccinella septempunctata brucki Mulsant (Coleoptera: Coccinellidae) and Its Migration to Alfalfa Fields

Abstract

Overwintering Coccinella septempunctata brucki adults were found in mounds and bunches of Japanese pampas grass in central Japan in February. Most adults were found in the south- and east-facing mounds, where the air temperature was 2°C-6°C higher and there were more aphids than in the north-facing mound. Adult beetles started to migrate to an alfalfa field infested with aphids in early spring, when daily maximum temperatures exceeded 12°C, but only few adults migrated to a field where the aphids had been eliminated. Some of the adults marked in their overwintering sites were recaptured in the alfalfa fields.In August, aestivating adults were found mainly in the bunches of Japanese pampas grass and some of the adults marked in August were recaptured in the alfalfa fields in the next spring. © 1993, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.