A severe outbreak of the pine-tree lappet, Den-drolimus pini (L.), was unexpectedly discovered in 2012 on a small, fairly isolated island in the Stockholm archipelago (Fig. 1). This is the first outbreak of D. pini recorded in Sweden during the last 70 years, although the species occurs in moderate densities in conifer forests over southern and central Sweden. In this paper we present data and pictures documenting this rare outbreak after briefly presenting the basic biology of the species and its outbreak history in Europe. In addition, we raise and try to answer questions that naturally arose as a consequence of this rare event.
展开▼
