Effect of Photoperiod and Temperature on the Diapause Termination of the Kanzawa Spider Mite, Tetranychus kanzawai Kishida(Acari: Tetranychidae)

Abstract

Mochizuki, M . and A. Takafuji, 1996. Effect of photoperiod and temperature on the diapause termination of the Kanzawa spider mite, Tetranychus kanzawai Kishida(Acari: Tetranychidae). J. Acarol. Soc. Jpn., 5(2): 83-88.
Reproductive diapause of the adult females of the Kyoto population of Tetranychus kanzawai induced under laboratory conditions ended much faster under long-day(16L8D)than under short-day(9L15D). Temperature also played a part; the diapause ended quicker at 20°C than at 15°C. The majority of females did not require any chilling for diapause termination. These results suggested that the diapause intensity of T. kanzawai in central Japan was weak and short-days maintained diapause. Overwintering adult females collected from a tea field in Shizuoka gradually lost sensitivity to short-days after December. More than half of the females collected in late December started oviposition within about 10 days when exposed to both short-days and tolong-days. This result indicated that the diapause of T. kanzawai had ended by mid-winter.