Insecticidal potential of botanical extracts for management of, the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae)

Abstract

Background Bactrocera dorsalis (Hendel) poses a significant threat to global fruit production and quality, including in Pakistan, where it causes substantial losses. Traditional control methods have heavily relied on the indiscriminate and imprudent use of insecticides, leading to challenges such as insecticide resistance, environmental pollution, fruit contamination, and health risks. This study explores the insecticidal potential of seven selected botanicals: Artemisia vulgaris L., Capparis spinosa L., Mentha longifolia, Mentha piperita, Peganum harmala, Eucalyptus globulus, and Callistemon viminalis, each at three different concentrations (10mL, 20mL, and 30mL), against Bactrocera dorsalis (B. dorsalis). Two in vitro experiments involving the application of plant extracts mixed with protein bait and direct spray were conducted. Results Both experimental results demonstrated a direct correlation between the concentration of plant extract and the mortality of B. dorsalis. In the plant extract mixed with protein bait, results recorded after 96 h at 10 mL ranged from 8.667 ± 1.52–47.000 ± 3.00, at 20 mL from 18.667 ± 1.52–53.667 ± 6.02, and 30 mL from 26.000 ± 5.29- 67.667 ± 2.08. Meanwhile, for direct spray, mortality ranged from 2.333 ± 1.15–32.333 ± 6.80 at 10 mL, 1.000 ± 1.00–42.667 ± 7.02 at 20 mL, and 9.667 ± 2.30–61.333 ± 8.50 at 30 mL, respectively. The plant species exhibiting the highest toxic potential against the respective pests was C. viminalis, followed by A. vulgaris L. In contrast, the least toxic effect was observed in Eucalyptus globulus at all concentrations. The highest mean mortality and repellence % were recorded in C. viminalis and E. globulus in both experimental trials. The results revealed the highest efficacy of C. viminalis with an LC50 value of 9685.15 and 19,909.11 ppm, for the extract mixed with protein bait and sprayed, was obtained, respectively, the most toxic to the pest followed by the extracts E. globulus and C. spinosa L. Conclusion Based on our experimental results, it is concluded that C. viminalis and A. vulgaris L. are an effective alternative for the management of B. dorsalis.