Some biological traits of the parasitoid wasp Rhopalicus tutela (Hymenoptera: Pteromalidae) in spruce forests of Moscow Region, Russia

Some biological traits of Rhopalicus tutela (Walker), a parasitoid of the European spruce bark beetle Ips typographus (L.), were studied both in forests of Moscow Region, Russia, and under laboratory conditions. Females of R. tutela have mature eggs after overwintering and thus do not need additional feeding to lay eggs. Under laboratory conditions at 8 °C, the life expectancy of males is 58±44 days and that of females is 36±45 days. An increase of temperature shortens the developmental period of R. tutela, which can proceed without diapause. The duration of one generation in the laboratory at 22–24 °C is 14–16 days. In spruce forests of Moscow Region, R. tutela has two or three generations per year.

NOTES ON THE BIOLOGIES OF HYMENOPTEROUS PARASITES OF IPS SPP. BARK BEETLES IN VIRGINIA

Biological data are given for Coeloides pissodis (Ashmead), Dendrosoter sulcatus Muesebeck, Heterospilus sp., Spathius pallidus Ashmead, Eurytoma conica Provancher, Cecidostiba polygraphi Ashmead, Heydenia unica Cook and Davis, Roptrocerus xylophagorum (Ratzeburg), Rhopalicus pulchripennis (Crawford), Rhopalicus tutela (Walker), and Tomicobia tibialis Ashmead. Only Coeloides pissodis was always closely associated with its host. The other larval parasites were often found disassociated from any host, suggesting an ability to seek out hosts in Ips galleries and the potential to attack more than one host. Observations indicated that pupal parasitism may be significant. Comment on the potential of some parasites as control agents is included.