Performance of the potentially invasive Siberian moth Dendrolimus superans sibiricus on coniferous species in Europe.
The native range of the Siberian moth extends from the Pacific Ocean (Russian Far East, Japan and Northern Korea) across Siberia, Northern China and Mongolia to the Ural Mountains. At the beginning of the 21st Century, this species was documented west of the Ural Mountains in the Republic of Mari El, indicating range extension toward the west. The Siberian moth has recently been suggested for regulation as a quarantine pest for European and Mediterranean Plant Protection Organization member countries. However, no specific report on European host plants for this pest has been published so far. In the present study, larval host plant choice and performance was tested for the first time on coniferous tree species that are widely distributed and of commercial value in Europe. Based on dual-choice tests on neonates and mortality, developmental duration and relative growth rates of the first- to sixth-instar larvae, we found European larch Larix decidua to be the most suitable host for the moth larvae, whereas European black pine Pinus nigra and Scots pine Pinus sylvestris were the poorest hosts. The remaining conifer species tested, European silver fir Abies alba, Nordmann fir Abies nordmanniana, and Norway spruce Picea abies, were intermediate host plants. Douglas-fir Pseudotsuga menziesii, originating from North America, was chosen by the larvae to the same extend as European larch, and was also highly suitable for larval development. If the moth is introduced to European countries, it will become damaging in stands of European larch and Douglas-fir, mixed stands of fir and spruce; however, it will be less damaging in forests dominated by two-needle pines. We predict that Dendrolimus superans sibiricus will be able to survive and develop on the main European coniferous tree species, including non-native coniferous tree species, resulting in severe damage to large areas of forests.