Are the moth larvae able to withstand tree fall caused by wind storm?

Abstract

Wind storms play an important role in structuring European forests, however, the direct effects of strong wind on insects roosting in tree canopies are poorly known. In this study we assess the proportion of moth larvae which remain on Norway spruce (Picea abies [L.] Karst.) trees which have fallen during high winds. Next, we contribute to the knowledge of potential importance of such larvae in forests fragmented by local wind damage. We studied the effects of wind in spruce forest in the West Carpathians in March 2013. Branches were sampled from randomly chosen fallen and standing (undamaged) spruce trees in April 2013. Larvae or emerged moths were obtained from branches in the laboratory using photoeclectors. Assemblages of larvae were analysed at community level using several approaches. In total, 11 species of Lepidoptera were found on the branches, 10 of them overwinter as larvae and one as eggs. No differences were observed between abundance and species richness of larval assemblages on fallen and standing trees. Assemblages were very similar; there was no difference detected between standing and fallen trees. Overwintering larvae can successfully complete their development on wind-felled trees; hence, the emerged moths may contribute to greater infestation of standing spruce trees surviving wind disturbance.

Keywords

• norway spruce, moth larvae, wind storm, mountain forest, forest protection, central europe