Articles by Niklas Björklund

Adult pine weevils (Hylobius abietis (L.)) feed on the tender bark of branches and roots of mature conifer trees and on the stem bark of conifer seedlings. Their feeding on mature trees does not cause any economic damage, but their feeding on planted seedlings is so devastating that the pine weevil is considered one of the most important forest pest insects in Europe. We asked whether the pine weevil prefers seedlings over other regularly utilized food sources. This question is of particular interest because new approaches to seedling protection are based on decreasing any preference for seedlings by using less palatable plants or by enhancing their defence (by genetic selection or by methyl jasmonate treatment). In a laboratory choice experiment we tested pine weevil feeding preferences for seedlings compared with branches and roots from mature trees (separately for Norway spruce and Scots pine). Pine weevils preferred roots, but not branches, of Norway spruce over seedlings of the same species. With Scots pine there were no clear preferences, but the weevils showed a tendency to prefer roots over seedlings. These results provide support for seedling protection approaches that attempt to redirect pine feeding from planted seedlings to other food sources.

• Fedderwitz, Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, SE-750 07 Uppsala, Sweden E-mail: frauke.fedderwitz@slu.se
• Björklund, Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, SE-750 07 Uppsala, Sweden E-mail: niklas.bjorklund@slu.se
• Ninkovic, Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, SE-750 07 Uppsala, Sweden E-mail: velemir.ninkovic@slu.se
• Nordlander, Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, SE-750 07 Uppsala, Sweden E-mail: goran.nordlander@slu.se