抄録
The smaller tea tortrix and the summer fruit tortrix occur synchronously throughout the frlight season in the sympatri areas. Mating times of the two species under the natural conditions of light were not significantly different in June-July, but there was about a 2-hour difference in November. Observatons at 20°C, under various light-dark (LD) cycles, revealed about a one-hour difference in mating time under a 12 : 12 LD-cycle. The difference was smaller under shorter scotophases. From the seasonal day-length in the sympatric areas, the different timings of matin alone seemed not to be enough for the isoltion between he two species.
