Adult Diapause of the Fleabeetle, Argopistes biplagiatus MOTSCHULSKY(Coleoptera:Chrysomelidae) : II. Effects of Photoperiodic Conditions on Feeding and Oviposition Activities

Abstract

At 20°C, amount of food consumption of Argopistes biplagiatus adults collected from the field in early autumn was greater under short-day conditions (11L-13D, 12L-12D and 13L-11D) than under long-day conditions (14L-10D, 15L-9D and 16L-8D). Females laid no eggs when they were transferred from 11L-13D, 12L-12D, 13L-11D, 14L-10D, 15L-9D or 16L-8D to 12L-12D, and from 14L-10D, 15L-9D or 16L-8D to 15L-9D, but they laid eggs when they were transferred from 11L-13D, 12L-12D or 13L-11D to 15L-9D. These results, together with those in previous field and laboratory studies, suggested that A. biplagiatus undergoes aestival (summer) diapause which is maintained by the long day-lengths and terminated by the short (or decreasing) daylengths and autumnal-hibernal (winter) diapause which is induced (and maintained) by the short (or decreasing) daylengths and terminated by the long (or increasing) daylengths in the adult stage.