The diversity and phylogeography of cynipid gallwasps (Hymenoptera: Cynipidae) of the Oriental and eastern Palearctic regions, and their associated communities

Abstract

Cynipid gallwasps comprise around 1300 species worldwide, predominantly in temperate regions of the Holarctic. The vast majority of species are recorded either from the Nearctic or the Western Palearctic, both of which are long-standing centers of research on the taxonomy and biology of this group. In contrast, the eastern Palearctic fauna is little studied, but potentially extremely rich. The known gallwasps of eastern Asia fall primarily into three tribes: the oak gallwasps (Cynipini), the rose gallwasps (Diplolepidini) and the cynipid inquilines (Synergini). Recorded species richness for all cynipid groups in the eastern Palearctic is probably significantly underestimated, and we predict that this will be particularly true for gallwasps associated with oaks in the subgenera Quercus and Cyclobalanopsis, and perhaps for related host plants in the Fagaceae. We summarize what is known for all gallwasp tribes in the region extending from Pakistan to Japan and south to Indonesia, and highlight contributions that work in this region has made to understand the biology of this group as a whole. We focus in particular on the oak gallwasps, for which patterns in regional diversity across the Holarctic are best understood.