Work

Bioactivity of essential oils against the vine mealybug Planococcus ficus and its associated ant Brachymyrmex patagonicus

Year: 2026

Type: article

Abstract: Planococcus ficus (Hemiptera: Pseudococcidae) is a major vineyard pest, frequently protected and dispersed by ants, which complicates its management. The aim of this study was to evaluate the insecticidal and repellent effects of essential oils (EOs) from Aloysia polystachya , Pimenta haitiensis , Curcuma longa , Cymbopogon nardus , Illicium verum , Pimenta racemosa , Pinus ponderosa , and Syzygium aromaticum against P. ficus and its associated ant, Brachymyrmex patagonicus . Fumigant toxicity assays revealed that A. polystachya , C. nardus , I. verum , and P. racemosa EOs caused 100% mealybug mortality after 48 h. In surface contact tests, S. aromaticum and C. longa were the most effective, whereas direct spraying assays identified C. longa and P. racemosa as the most active EOs at 24 h. Essential oils of C. longa , P. racemosa , and S. aromaticum also exhibited repellent activity against mealybugs. Additionally, EOs disrupted ant behavior, causing hyperactivity and disorientation. Treated areas significantly reduced movement time, stopped time, and distance walked, while increasing ant speed compared to controls, with P. ponderosa , P. racemosa , and S. aromaticum being the most effective. Overall, C. longa and P. ponderosa did not exhibit phytotoxic effects on grapevine leaves at the tested dose under laboratory conditions, whereas P. racemosa and S. aromaticum caused only low to moderate phytotoxicity. These results suggest that, with appropriate dose optimization and formulation strategies, these EOs represent promising candidates for the development of alternative bio-based plant protection products against P. ficus and its associated ant. Further field studies are required to validate these results under real-world conditions and optimize their application within integrated pest management programs.

Source: Journal of Natural Pesticide Research

DOI: 10.1016/j.napere.2026.100210