Edge distributions of Ceutorhynchus assimilis and its parasitoid Trichomalus perfectus in a crop of winter oilseed rape (Brassica napus).

摘要: The edge distributions of Ceutorhynchusassimilis and its parasitoid Trichomalusperfectus within a crop winter oilseed rape were investigated between May July using yellow water-traps arranged on grid system. A randomisation test, which compared the observed arrangement trap counts with permuted arrangements, was used to quantify tendency C. assimilisto congregate at edges as it migrated into crop; this declined during season. Trichomalus perfectus distributed only early phase immigration in May, occurred later than host. It is considered that simple means quantifying insect spatial distribution could prove useful tool precision targeting insecticides.