Epsilon Archive for Student Projects

Abstract

The pine weevil (Hylobius abietis (L.)) is one of the most destructive pests in Swedish conifer plantations. Many efforts have been made to reduce its damage by the use of insecticides, planting site preparation, physical barriers and other management practices. A number of studies show the importance of ants in pest management in different systems. In this study I test the hypothesis that a high density of ants reduces damage on conifer seedlings by the pine weevil.

The study was conducted on two clearcut areas in the Lunsen forest S of Uppsa-la, Sweden. In total, 900 Norway spruce seedlings (Picea abies (L.) Karst.) were planted (divided into plots with 25 seedlings) and different measures of the weevil’s damage were assessed, i.e. proportions of attacked and girdled seedlings, and mean feeding area. Densities of the ant species Formica polyctena and Myrmica ruginodis were obtained weekly by pitfall traps placed in each planting plot. No significant relationship between ant density and weevil damage was found when tested by means of the Spearman’s correlation. Results elucidating the process of pine weevils damaging seedlings are reported.