TOXICOLOGICAL ASSESSMENT OF CERTAIN ACARICIDES ON VARROA DESTRUCTOR AND HONEY BEES, APIS MELLIFERA UNDER LABORATORY AND FIELD CONDITIONS

Konper, . Hanan M. A; Seddik,, M. A; Amer,, S. M; Anter, M. A

doi:10.21608/mjapam.2025.421160.1051

TOXICOLOGICAL ASSESSMENT OF CERTAIN ACARICIDES ON VARROA DESTRUCTOR AND HONEY BEES, APIS MELLIFERA UNDER LABORATORY AND FIELD CONDITIONS

Document Type : Original Article

Authors

¹ Department of Apiculture, Plant Protection Research Institute, Agricultural Research Center, Dokki, 12619 , Giza, Egypt.

² Department of Plant Protection, Faculty of Agriculture, Al-Azhar University, Cairo

10.21608/mjapam.2025.421160.1051

Abstract

The present study evaluated the acute contact toxicity and field efficacy of four acaricides: coumaphos, tau-fluvalinate, oxalic acid, and the thymol-based formulation Varoviga against Varroa destructor and honey bee workers (Apis mellifera) at varying concentrations. Laboratory bioassays demonstrated clear differences among the tested compounds. After 12 and 24 hours of exposure, coumaphos consistently exhibited the highest potency against mites, with LC₅₀ values of 2.28 and 1.34 µg/mL, respectively, while maintaining selectivity toward honey bees (LC₅₀ = 27.33 and 18.24 µg/mL). Oxalic acid and tau-fluvalinate showed moderate toxicities to V. destructor (LC₅₀ = 25.89–21.26 µg/mL and 32.96–24.69 µg/mL, respectively), whereas Varoviga® was the least effective (LC₅₀ = 157.95–124.67 µg/mL). For honey bees, the toxicity ranking differed: coumaphos was most toxic (LC₅₀ = 27.33–18.24 µg/mL), followed by oxalic acid (86.81–71.42 µg/mL), tau-fluvalinate (334.71–296.07 µg/mL), and Varoviga® (526.26–443.16 µg/mL). These findings confirm that although synthetic acaricides provide strong control of mites, they may also pose significant risks to bee health if misused or applied in excessive amounts. Field trials corroborated laboratory findings, with coumaphos producing the highest mite drop, closely followed by oxalic acid. Tau-fluvalinate and Varoviga were less effective, but they still significantly reduced infestations compared to untreated controls. The combined results emphasize the importance of balancing acaricidal potency with honey bee safety and highlight the potential of integrating natural products, such as oxalic acid and thymol formulations, into honey bee treatment programs to enhance sustainability and delay the development of resistance.

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