Studies on the biology of the apple fruit moth - influences of the fruits on the establishment, growth and diapause of the larvae.
The influence of the fruit on the establishment, growth and diapause of the larvae of Carposina niponensis Wlsm., an important pest of pome and stone fruits in China, is described from investigations in Liaoning Province in 1962-63. There were 2 generations a year, but some first-generation larvae entered diapause. The eggs were usually deposited near the calyces in pome fruits, and the growth stages and specific and varietal differences in the fruits influenced successful penetration by the larvae. Pears were more resistant in the early stages of growth, but became more susceptible as they grew. Second-generation larvae were therefore better able to bore into the fruits, and their rates of survival were higher than those of the first generation. The rates of larval growth were influenced by temperature as well as by specific and varietal differences of the fruits. Survival rates were lowest in the apple variety Kuo-kung, and the incidence of diapausing larvae was highest in this variety. It is suggested that these findings can be of value in designing chemical control measures against C. niponensis in different fruit orchards.