Effects of temperature on the development and fecundity of Thrips nigropilosus (Thysanoptera: Thripidae) on Chrysanthemum morifolium (Asterales: Asteraceae)

The development, reproduction, and population growth of Thrips nigropilosus Uzel (Thysanoptera: Thripidae), reared on leaves of Chrysanthemum morifolium Ramat (Asteraceae), were studied at seven different constant temperatures. Temperature and development rate of T. nigropilosus from egg to adult were linearly related between 15 and 25 °C, allowing the calculation of a lower threshold of 9.26 °C and a thermal constant of 238.1 degree-days. At 35 °C, eggs failed to hatch and larvae did not develop into adults. Adult longevity decreased with increasing temperature between 15 and 35 °C and females lived longer than males. Mean fecundity was highest at 30 °C, with 42.4 eggs per female. The intrinsic rate of natural increase was highest at 30 °C 0.173. During the late summer to spring, which is the main cultivation season for chrysanthemum in Okinawa, a maximum of 11 generations of T. nigropilosus could occur according to our calculations based on meteorological data from 2015 to 2016.