INFLUENCE OF SNOW COVER ON THE OVERWINTERING OF THREE SPECIES OF GALL-FORMING DIPLOLEPIS (HYMENOPTERA: CYNIPIDAE)

Abstract
Prepupae of three species of Diplolepis (D. nebulosa (Bassett) a leaf-gall-former, an undescribed stem-gall-former, and D. radicum (Osten Sacken), a root-gall-former) were overwintered at various heights above the ground. Most prepupae of all three species buried beneath the snow survived the winter, while only stem-gall-formers survived at a height subject to fluctuating snow depths. All specimens of the three species that overwintered above the snow were killed.