The efficacy of allyloxy-4 propoxybenzene (3c{3,6} against Varroa destructor mites in honey bee (Apis mellifera) colonies from Maryland, U.S.A

Authors: Cook, Steven; Johnson, Josephine; Rogers, Curtis; Sachs, Ian; FENG, XINYI - Simon Fraser University; PLETTNER, ERIKA - Simon Fraser University

Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2023
Publication Date: 5/28/2024
Citation: Cook, S.C., Johnson, J.D., Rogers, C.W., Sachs, I.E., Feng, X., Plettner, E. 2024. The efficacy of allyloxy-4 propoxybenzene (3c{3,6} against Varroa destructor mites in honey bee (Apis mellifera) colonies from Maryland, U.S.A. Journal of Insect Science. 24(3):9. https://doi.org/10.1093/jisesa/iead111.
DOI: https://doi.org/10.1093/jisesa/iead111

Interpretive Summary: Varroa destructor (Acari: Varroidae) are harmful ectoparasites of Apis mellifera honey bees, and are believed to be the greatest threat to the health and well-being of the beekeeping industry, particularly in North American and Europe. Beekeepers have dwindling number of treatment options against the mites due to Varroa gaining resistance to many of the conventional pesticides used for its control, thus novel treatment options would be welcomed. In this study we describe results from a field trial conducted in Maryland, USA, using the compound 1-allyloxy-4-propoxybenzene (3c{3,6}), which has demonstrated efficacy against mites in previous laboratory and field trials conducted elsewhere. The compound had minimal effect on exposed honey bees, and a calculated efficacy against mites of ~78.5%, indicating that this compound shows promise as a varroicidal treatment. However, recovery of mite populations post-treatment suggest dosing and/or application regimen may need to be modified in the future to boost long-term efficacy.

Technical Abstract: Varroa destructor (Acari: Varroidae) is a harmful ectoparasite of Apis mellifera honey bees causing widespread colony losses in Europe and N. America. To control populations of these mites, beekeepers have an arsenal of different treatments, including both chemical and non-chemical options. However, non-chemical treatments can be labor intensive, and Varroa has gained resistance to some conventional pesticides, and the use of other chemical treatments is restricted temporally (e.g., cannot be applied during periods of honey production). Thus, beekeepers require additional treatment options for controlling mite populations. The compound 1-allyloxy-4-propoxybenzene (3c{3,6}) is a diether previously shown to be a strong feeding deterrent against Lepidopteran larvae or a repellent against mosquitoes. The compound 3c{3,6} showed promise as a novel acaricide from laboratory and early field trials. Here we test the effect of the compound, applied at 8 g/brood box on wooden release devices, on honey bees and Varroa in field honey bee colonies located in Maryland, USA, using a thymol-based commercial product as a positive control. 3c{3,6} had minimal effect on honey bee colonies, but more tests are needed to determine whether it affected egg production by queens. 3c{3,6} had an estimated efficacy of 78.5% while the positive control thymol product showed an efficacy of 91.3%. 3c{3,6} is still in the development stage, and dose or application need to be revisited.