Effects of oilseed rape plant density on herbivores

摘要

In an experiment conducted in Pawowice near Wrocaw, Poland, during 2004-05, 2 cultivars of winter oilseed rape (Lisek and Titan) were grown in 15-m2 plots at a density of 40 and 120 seeds/m2. For both cultivars, the number of pollen beetles [Meligethes spp.] was higher under he lower sowing rate (40 seeds/m2). The total number of beetles was higher on Titan than on Lisek. Damage caused by stem weevils [Ceutorhynchus spp.] was greater on plants grown at a lower density. The total number of tunnels, length of tunnels, and percentage of plants with more than 2 tunnels was also greater under a lower plant density..