Pests of Oilseed Rape and Parasitoids of the Cabbage Aphid Brevicoryne Brassicae L. in Eastern Algeria

This study reports the first comprehensive survey of insect pests associated with oilseed rape (Brassica napus L., InVigor variety) in the Guelma region, eastern Algeria, with a focus on the parasitism of the cabbage aphid Brevicoryne brassicae (Linnaeus, 1758). Sampling was conducted over a 6-hectare plot using yellow traps (pre-flowering), beating (full bloom), and direct sampling (post-flowering). The pest complex included the pollen beetle Brassicogethes aeneus (Fabricius, 1775), the flea beetle PsyUiodes chrysocephala (Linnaeus, 1758), Ceutorhynchus spp., Tropinota spp., the bird cherry-oat aphid Rhopalosiphum padi (Linnaeus, 1758), the green peach aphid Myzus persicae (Sulzer, 1776), and B. brassicae. During fruit maturation, two dominant primary parasitoids of B. brassicae were recorded: Diaeretiella rapae (McIntosh, 1855) and Lysiphlebus testaceipes (Cresson, 1880). Hyperparasitoids, including Pachyneuron aphidis (Bouche, 1834), Asaphes vulgaris (Walker, 1834), and Syrphophagus sp., were also detected and may reduce the effectiveness of biological control.