Convex flea beetle

Systematic position. The convex flea beetle (Psylliodes convexior) is a member of the Coleoptera order and the Chrysomelidae family. This pest species is recognized for its ability to cause significant economic losses in various vegetable and oilseed crops, particularly during the early emergence stages of the plants.

Host crops. The pest primarily targets plants within the Brassicaceae family. Key agricultural hosts include cabbage, radish, mustard, rapeseed, and various turnip varieties. Additionally, the beetle thrives on wild cruciferous weeds, which serve as essential reservoirs for their populations throughout the cropping season.

Biology and life cycle. The life cycle consists of egg, larval, pupal, and adult stages. The adult beetles overwinter in soil or sheltered plant debris. In the spring, as temperatures rise, adults emerge to feed on seedlings. Females subsequently lay eggs in the soil, and the larvae feed on the roots or underground stems, which often leads to hidden, cumulative damage to the plant health.

Type of damage and economic impact. Adults create small, irregular shot-holes in the foliage, reducing the photosynthetic capacity of the leaves. Severe infestations can lead to total crop failure during the seedling stage. Larval damage to the root system is more insidious, causing wilting and stunted growth, which makes the plant more susceptible to secondary infections and environmental stress.

Protection measures. Effective control requires a comprehensive Integrated Pest Management (IPM) approach:

• Implementing strict crop rotation to disrupt the pest's life cycle.
• Applying mechanical soil cultivation to destroy overwintering sites.
• Maintaining field borders free of cruciferous weeds.
• Using systemic insecticidal seed treatments to provide early-season protection.
• Monitoring fields regularly and applying foliar sprays when the economic injury level is reached.