前胸背斑紋が連続し,幼虫休眠性をもたないキボシカミキリ東日本型の分布域である茨城県つくば市の蚕糸・昆虫農業技術研究所の圃場周辺で1990年と翌91年の2年間,成虫を捕獲調査した。前胸背斑紋が明らかに中断している個体が雄で50%前後,雌で30%台と多かったこと,両年とも6月中旬に幼虫休眠後羽化したと思われる大きな捕獲ピークを認めたこと等から,前胸背斑紋が中断し,かつ幼虫休眠性をもつ個体群,すなわち西日本型が,捕獲個体群中にかなり混入していると判断した。1992年10月に捕獲した雌成虫から得た次世代幼虫の飼育結果からもこのことが確認された。今回の調査結果は,SAKAKIBARA and KAWAKAMI (1992)の結果から導かれる,(1)両型の混棲地では性比は季節変化を示し,(2)斑紋型は休眠性の判断指標として不適当であるとの,2つの推論を支持するものであった。
Haemolymph and whole-body trehalose contents in overwintering larvae of Enosima leucotaeniella were measured by gasliquid chromatography. The volume of haemolymph (Vμl) was determined by the following relationship: V=(T2/T1)×1, 000, where, T1 is the haemolymph trehalose concentration (mg/ml) and T2 is the whole-body trehalose content (mg). This estimate was comparable in accuracy with the 14C-inulin-dilution method. During October to March 1993 and 1994, the trehalose concentration in haemolymph was controlled by ambient temperature. However, the volume of haemolymph barely changed (55% to 65%) during October to February, but decreased markedly in March. Physiological changes such as decreased body glycogen and increased glucose content were also noticed in March. Therefore, the decreased haemolymph volume may be one phenomenon in a series of physiological changes of overwintering larvae in the late post-diapausing stage.
Transmission of an entomogenous fungus, Beauveria brongniartii, by mating behavior was examined by allowing inoculated Psacothea hilaris adults to mate with non-inoculated ones. There was a significant difference in transmission ability between inoculated males and females. Inoculated adults could transmit the fungus to non-inoculated ones for five successive days, mating once each day after inoculation. The transmission percentage was 100% for adults 2h after inoculation but decreased to 40%-60% 5 days after inoculation.