抄録
Overwintering females of Pseudaulacaspis pentagona (Targioni-Tozetti) entered reproductive diapause, and the ovarian development in females collected before the end of the year was retarded, but development proceeded normally after the beginning of the year. I examined the effects of temperature on the maintenance and termination of diapause in overwintering females that were reared on pumpkin fruits under natural conditions and then transferred to laboratory conditions. Reproductive diapause was averted by a high temperature of 25°C, irrespective of the time of transfer. In contrast, temperatures of 22.5 and 20°C maintained the diapause when the overwintering females were transferred before the winter solstice. Reproductive diapause gradually terminated at a temperature of 17.5°C. Diapause development proceeded when females were reared at 15°C, and in early to mid-February the females began to lay eggs in the samples transferred between November and January. Diapausing females continuously fed on the pumpkin fruits and added secretory materials to the scale cover after being transferred to the incubators. The scale cover, which became thick during diapause, might protect the insect against adverse environmental conditions.
