Biological Control and Host Plant Resistance as Pillars of Integrated Pest Management in Cabbage (Brassica oleracea var. capitata): A Global Review

Cabbage and allied brassicaceous crops are among the most economically important vegetables cultivated globally, yet they are subjected to severe yield losses caused by a diverse assemblage of insect pests. Conventional chemical control, whilst effective in the short term, has engendered widespread insecticide resistance, environmental degradation, and negative consequences for non-target organisms and human health. Against this backdrop, biological control strategies and the deployment of resistant plant varieties have emerged as pivotal components of sustainable pest management. This review synthesises evidence from peer-reviewed literature on (i) the major insect pest species threatening cabbage production worldwide, (ii) the efficacy and limitations of biological control agents including parasitoids, predators, entomopathogenic microorganisms, and botanical biopesticides, and (iii) the mechanisms and applications of host plant resistance in Brassica species. Special attention is given to the glucosinolate myrosinase defence system, the role of physical plant traits, and advances in molecular and biotechnological breeding. The review further discusses the integration of biological control and resistant varieties within comprehensive integrated pest management (IPM) frameworks, including trap cropping, habitat manipulation, and pheromone-based monitoring. Key findings indicate that whilst substantial progress has been made in individual biological control tactics, the greatest sustainable gains are achieved through multi-component IPM programmes that harness the complementarity of diverse pest management tools. Critical challenges persist regarding the inconsistent field performance of biopesticides under varying environmental conditions, the potential for resistance evolution to plant-derived defences, and the limited adoption of IPM in smallholder farming systems.