Development and reproductive capacity of Thrips hawaiiensis (Thysanoptera: Thripidae) and its potential as a major pest.

The effect of constant temperature on development, reproduction and population growth of Thrips hawaiiensis (Morgan) reared on a diet of pollen and honey solution was studied. Although hatchability and survival rates from egg hatch to adult were higher than 79% between 15 and 25 degrees C, they were lower than 55% at 10 and 30 degrees C. Developmental rates increased linearly as rearing temperature increased. It was estimated that 153.8 degree-days, above a lower threshold temperature of 10.4 degrees C, were required to complete development from egg to adult oviposition. According to these figures, between 11 and 18 generations of T. hawaiiensis could have developed annually under outdoor conditions in western Japan, between 1990 and 1999. Mean adult longevity decreased with increasing temperature, from a maximum of 102.7 days at 15 degrees C to a minimum of 27.8 days at 25 degrees C. The mean fecundity on pollen and honey solution was highest at 20 degrees C with 536.9 eggs per female. The highest intrinsic rate of natural increase (rm) 0.208 was observed at 25 degrees C.