ACTIVITY AND REPRODUCTION OF CALOSOMA-FRIGIDUM (COLEOPTERA, CARABIDAE) IN NORTHERN MICHIGAN FORESTS

From 1985 to 1991, activity patterns of Calosoma frigidum were assesse d by means of pit-trapping at weekly intervals from early May to late October in two deciduous forest sites in northern Michigan. Females we re dissected in order to document ovarian development. The species was spring-breeding, with activity of gravid females peaking in May-June, and with spent females present from late May to July and occasionally into August. In 1988, only one of 85 females was gravid, a phenomenon apparently related to delayed emergence From hibernation. Asynchronis m between time of emergence and early spring shifts from short-day to long-day (critical for vitellogenesis) was postulated as the underlyin g cause for reproductive failure in 1988. In both sites, the species e ssentially disappeared after 1988.