Preference and Performance of the Pine-Tree Lappet Dendrolimus pini on Various Pine Species

Abstract

Global commercial and recreational transport may lead to the unintentional invasion of insect species, which in turn may pose a threat to native organisms. In this study, we aimed to assess whether the economically important pest of Pinus sylvestris L., moth Dendrolimus pini L. (DP), is able to feed on nine other pine species, and how this will affect its survival, performance, growth, and development. We carried out food choice tests and a no-choice laboratory feeding experiment. We found that this insect mostly preferred its prime host, but also Pinus cembra L., Pinus contorta Douglas ex Loudon, Pinus nigra J.F.Arnold, and Pinus ponderosa Douglas ex C.Lawson. The performance test revealed a host-specific response of DP to the host plant. This response was manifested in a large variation in body mass as well as in a decrease or increase in life-history traits, such as fecundity, and wing morphology parameters. However, the larvae’s choice of particular hosts corresponded to the results of the performance test. Larvae more willingly selected food allowing better results in their performance. Larvae achieved better values of growth and development when fed on European and North American pine species or on species with two- and three-needle fascicles. In addition, attractants and repellents in needles of different pine species were chemically analyzed. Variations in the secondary metabolite composition as well as the specific leaf area of different pine species effectively explained the results found in the insects, but the content of sugars and nitrogen remains to be elucidated. We speculate that DP poses a serious threat to large areas of pine forests, if transferred, as it can survive and develop on many economically important tree species in North America and Europe.