A Taxonomic Study Of Ichneumonids(Hymenoptera: Ichneumonidae) Parasitizing Wood-borers In Palearctic Part Of China

Ichneumonids, an important kind of parasitoids of wood-borers, can directly drill into tree trunk deeply by their long ovipositors and lay eggs on surface or into the bodies of their hosts which are damaging in xylem. As the unique parasitic function, they can effectively control wood-borers, and play a decisive role in the control of wood-boring insects. Ichneumonids parasitize on surface or in bodies of borers in xylem or under bark so that the research on them is very difficult. This is the primary causation that investigation on them is so little up to now.For conducting the biological control of the pests, investigations should be made first to find their effective natural enemies. Hymenopterous parasitoids, particularly ichneumonids, are among the most important natural enemies of wood-borers.Several methods were used in the process of the investigation.1) Bring the logs and branches naturally infested by wood-borers to the laboratory and kept in big nylon sheaths. Collecting the emerged insects daily from them.2) Rear parasitoid larvae and pupae. First collect the parasitoid larvae and pupae or cocoons from different wood-borer galleries on the naturally infested trees, then keep them in vials 2.8cm in diameter, one individual a vial with a piece of filter paper dipped in distilled water for keeping moisture, finally plug up the entrance of the vial tightly with absorbent cotton. Store them in the laboratory until they got mature and emerged.3) Directly collect the parasitoid adults with insect web on the infested tree trunks, branches and in forest.Based on the studies of over five thousand ichneumonid specimens collected and reared from many parts of north China, 44 genera and 121 species and subspecies belonging to 10 subfamilies of family Ichneumonidae parasitizing wood-borers are described in this dissertation, of which one genera and 15 species are new to science, 2 genera and 16 species new for China. 1 new synonym of species was indicated. More than 30 hosts are reported for the first time in China.Meanwhile, historical review on the subject in a global scale, the morphology and biology of those parasitoids are also dealt with. In the taxonomic part, keys to generatreated, each genus contains a short genus description, and within every genus keys tospecies and species description are provided in detail.