Chemical defense against cruciferous pests in spring rapeseed and mustard crops
Abstract
The cruciferous bug complex comprises several species, including the painted or harlequin bug (Eurydema ventralis Kol), pentatomid rape bug (E. oleraracea L.), and mustard bug (E. ornata L.). These insects belong to the Hemiptera order, Shield bug family (Pentatomidae), and Cruciferous bug genus (Eurydema). Among them, the predominant species is the cabbage bug, whereas the mustard bug held dominance solely in 2007, remaining absent from records since 2012. These bugs are widely distributed across the entire territory of Ukraine, causing damage to crops in both their adult and larval stages. They use their proboscis to puncture leaf surfaces and floriferous shoots, extracting plant juices. These feeding sites result in the formation of light spots, tissue death, and eventual loss of tissue leading to irregularly shaped holes. The bugs' presence also negatively impacts seed quality, as damaged seeds lead to dropped flowers and ovaries, culminating in reduced seed quality. Notably, the bugs' harmfulness escalates significantly during periods of dry and hot weather.