Insect Pest Complex of Brinjal and the Role of Natural Enemies and Plant Diversification in their Management

Brinjal (Solanum melongena L.) is one of the most widely cultivated solanaceous vegetables in Asia, but its productivity is seriously constrained by a diverse complex of insect pests. Among them, the shoot and fruit borer (Leucinodes orbonalis Guenée) remains the most destructive pest across all major growing regions, while jassid (Amrasca biguttula biguttula), aphid (Aphis gossypii), whitefly (Bemisia tabaci), and epilachna beetle (Henosepilachna vigintioctopunctata) are of moderate importance. Several studies across India and abroad have revealed that the seasonal incidence of these pests is strongly influenced by temperature, rainfall, relative humidity, and other abiotic factors, with L. orbonalis showing multiple population peaks during warm and humid periods. Natural enemies play a vital role in regulating brinjal pest populations, with predators such as coccinellids (Cheilomenes sexmaculata, Coccinella septempunctata), chrysopids (Chrysoperla carnea), spiders, syrphid flies, and parasitoids including Bracon spp. and Eriborus argentiopilosus contributing significantly to biological control. However, their abundance is also influenced by climatic conditions and crop management practices. Plant diversification through intercropping and border cropping has emerged as a promising strategy to suppress pest incidence and enhance natural enemy populations. Intercrops such as coriander, cowpea, onion, cluster bean, and marigold, as well as border crops like maize and pigeon pea, have been shown to reduce L. orbonalis infestation by 30–70% while simultaneously conserving beneficial fauna. This review consolidates research findings on the pest complex, seasonal incidence, role of natural enemies, and plant diversification strategies in brinjal ecosystems. It emphasizes the importance of integrating ecological principles into pest management to reduce dependence on chemical insecticides and promote sustainable brinjal cultivation.