SEASONAL FLUCTUATIONS IN BODYWEIGHT, LIPID-CONTENT AND THE STARVATION-LONGEVITY OF AMORBUS-OBSCURICORNIS (WESTWOOD) AND GELONUS-TASMANICUS (LE-GUILLOU) (HEMIPTERA, COREIDAE)

The live weight (LW) and dry weight (DW), lipid and water content and starvation-longevity of adult Amorbus obscuricornis and adult Gelonus tasmanicus were examined in successive seasons. Amorbus obscuricornis was consistently heavier than G. tasmanicus. In both species, water co ntent was inversely related to lipid content. The LW, DW and lipid con tents of A. obscuricornis were lowest in spring. In contrast, LW and D W of G. tasmanicus were highest in spring, whereas lipid content was h ighest in autumn. These differences appear to be related to the reprod uctive cycles of these species. Starvation-longevity of both species w as affected by relative humidity, being greatest at 99% and declining rapidly below 80%, and by temperature, being greatest for A. obscurico rnis at 10.6 degrees C and increasing for G. tasmanicus with decreasin g temperature to 4.5 degrees C. These differences may be related to di fferences in the habitat preferences of the two species, with G tasman icus apparently preferring cooler habitats than A. obscuricornis. It w as considered that the conditions that pre-wintering adults of, either species could withstand would facilitate their hibernation.