Flight potential and oxygen uptake during early dormancy in Coccinella septempunctata

Two flight parameters (take-off and duration) and respiration level were measured, in two years in summer and early autumn, in dormant Coccinella septempunctata L. (Coleoptera: Coccinellidae) collected while hidden in grass tussocks in hibernation sites (HID) and in beetles collected on plants (PLA). The duration of tethered flight of HID beetles measured in the laboratory in late August and September 1995 (range of geometric means 190-440 s) was slightly longer than the flight of PLA beetles (80-310 s), both being much longer than trivial flight recorded in beetles foraging for prey during the breeding season (35 s). In general, the flight performance had a tendency to increase in September and to decrease in October. The oxygen consumption in HID beetles increased throughout September 1994 from 430 to 780 mul g(-1) h(-1) and throughout October 1995 from 710 to 1060 mul g(-1) h(-1). This increase is ascribed to a concomitant decrease in diapause intensity. A similar increase was observed also in PLA beetles in 1994 and oxygen consumption was always higher than in HID beetles, most probably due to feeding and digestion in PLA beetles. Laboratory feeding of HID beetles on aphids induced maturation of ovaries and increased oxygen uptake (from 680 to 1110 mul g(-1) h(-1)). Feeding on honey and pollen left their oxygen uptake unchanged. Effect of feeding on the flight parameters was mostly not significant. In agreement with its less suitable body shape and usually less distant dormancy sites, C. septempunctata was found a less apt flier than long-distance migrating coccinellid species.