Allochthonous blue spruce in central Europe serves as a host for many native species of sawflies (hymenoptera, symphyta)

Abstract

In air-polluted mountain areas of the Czech Republic, including the Ore Mountains, pure forest stands of introduced blue spruce (Picea pungens) were established in the 1980's. We studied the Symphyta (Hymenoptera) fauna in the canopies of these trees at four sites and in the canopies of adjacent Picea abies trees at one of these sites by beating tree branches. For the first time, Nearctic blue spruce is reported as a host for 17 European species of Symphyta (sawflies). Diprionids in the genus Gilpinia were the most abundant sawflies on P. pungens and were more abundant on P. pungens than on the native Picea abies. Spruce pamphiliids in the genus Cephalcia were also more abundant on P. pungens than on P. abies, while the abundances of representatives of the tenthredinid genera Pikonema, Pachynematus, and Pristiphora were similar on P. pungens and P. abies. Our results indicate that many species of European spruce Symphyta are able to use the allochthonous species P. pungens as a host.