Gonocerus acuteangulatus

Systematic position: Gonocerus acuteangulatus belongs to the order Hemiptera and the family Coreidae. These insects, commonly known as leaf-footed bugs or squash bugs relatives, are characterized by their flattened body shape and prominent, sharp-angled pronotal lobes.

Host plants: This pest is known for its polyphagous nature, feeding on a variety of plants. However, it is primarily recognized as a significant pest in hazelnut (Corylus) orchards. It can also be found on several forest trees, including oak and hawthorn, which serve as alternative food sources and breeding grounds.

Biology and life cycle: The bug completes one generation per year. Adult insects overwinter in sheltered locations such as leaf litter, hedges, or under bark. As spring temperatures rise, adults emerge to feed on developing buds and shoots. Mating follows, and females deposit eggs on the host plants, leading to the development of nymphs during the summer months.

Nature of damage and economic impact: Damage is caused by both adults and nymphs piercing the pericarp of the developing hazelnut fruit. This feeding activity results in aborted kernels, internal necrosis, and often causes the nuts to drop prematurely. Infested nuts are typically hollow or shriveled, rendering them unfit for market use and significantly impacting the grower's profitability.

• Removing overwintering sites by cleaning orchard floors;
• Monitoring populations through visual inspection and pheromone traps;
• Applying targeted insecticides during the nymphal development stage if thresholds are exceeded;
• Managing hedgerows and nearby wild host plants to minimize migration into the orchard.