Effect of maturation feeding period on survival of Tomicus piniperda (Coleoptera : Scolytidae)

Callow adults of the pine shoot beetle, Tomicus piniperda L., were fed shoots of Scots pine, Pinus sylvestris L. (Pinaceae), to investigate the influences of shoot age and feeding duration on survival and weight of callow adults and to characterize the relationship between the volume of shoot tissue excavated and weight gain. Heavier callow adults had better survival than lighter ones, and survival was higher on current-year shoots than on 1-year-old shoots. A significant relationship was observed between the amount of tissue excavated by callow females on current-year shoots and their body weight gain, a trend not observed in callow males. These results suggest that beetle weight and survival may be reduced when availability of current-year shoots during maturation feeding is limited because of competition (i.e., during population outbreaks), thus negatively affecting the production of future generations.