Abstract
Aphelinus asychis from Kyoto and A. albipodus from Kobe, which enter weak diapause, strictly oligopause sensu Mansingh (1971), as adults and diapause as larvae, respectively, were reared under natural conditions in Kyoto to validate their overwintering dormancy and to compare previous laboratory results with dormancy-inducing and terminating photoperiods and temperatures in the field. In A. asychis, 30% of the females that had emerged in late October to early November survived until late March, but all males that had emerged in the same time died by mid-January. Some of the females oviposited in early and mid-November, but the females were likely to stop oviposition between late November and late January because no aphids that were exposed to the females were mummified. The surviving females oviposited from early February to late March, and adults of the first generation emerged in mid- to late April. Adult oligopause appeared to be induced by the photoperiod in mid- to late October and to be maintained for more than two months. In A. albipodus, mature larvae of the generation beginning in mid-October overwintered within the mummies, and adults emerged in mid- to late April. Larval diapause appeared to be induced by the photoperiod in mid-October and to be terminated by cold temperatures experienced at the end of January.
