The Effect of Food Bait with Boric Acid on the Mortality of Epuraea domina Reitter (Nitidulidae: Coleoptera) and Eco-Friendly Control Strategies

Abstract

Epuraea domina Reitter (Coleoptera: Nitidulidae), is a major flower-visiting pest causing significant economic damage to citrus orchards in Jeju, South Korea. During the flowering period, adults feed on nectar and pollen while scratching ovaries with their claws, leading to corky scars that degrade fruit quality and marketability. This study developed an eco-friendly management strategy using boric acid as a sustainable alternative to conventional chemical pesticides. Dietary toxicity was evaluated through two laboratory experiments: aqueous boric acid solutions (0.1–2.0%) and poison baits (0.5–6.0% boric acid mixed with dried citrus peel powder). Each treatment involved five replicates, with mortality recorded at 24, 48, and 72 hours post-exposure. Statistical analysis revealed that insecticidal efficacy was significantly dependent on both concentration and exposure duration. In both experiments, the 2.0% concentration demonstrated the highest efficacy, achieving over 96.0% mortality within 72 hours. Although lower concentrations exhibited slower initial toxicity, they reached high mortality levels as exposure time increased. These findings suggest that boric acid poison baits effectively suppress adult populations by targeting beetles at their breeding and emergence sites. Implementing this strategy within an Integrated Pest Management (IPM) framework offers a cost-effective and environmentally safe solution for reducing pest density during the critical flowering period. Ultimately, this approach enhances the productivity and quality of organic citrus farms while minimizing ecological impact.