Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2020
Publication Date: 6/1/2020
Citation: Rodriguez-Saona, C., Alborn, H.T., Oehlschlager, C., Calvo, C., Kyryczenko-Roth, V., Sunil Tewari, S., Sylvia, M.M., Averill, A.L. 2020. Fine-tuning the composition of the cranberry weevil (Coleoptera Curculionidae) aggregation pheromone. Journal of Applied Entomology. 2020;144:417–421. https://doi.org/10.1111/jen.12752.
DOI: https://doi.org/10.1111/jen.12752

Interpretive Summary: The cranberry weevil is a key pest of highbush blueberries and cranberries in the northeastern USA. In collaboration with a research group at Rutgers University, a scientist at the USDA-ARS Chemistry Research Unit in Gainesville, FL previously identified and field tested the aggregation pheromone of the cranberry weevil. An aggregation pheromone typically attracts large numbers of the insect to a food source. The pheromone differs from that of the closely related pepper weevil in that it lacks two constituents of the pepper weevil’s pheromone (E grandlure II and geranic acid). Here, we present results of field studies testing the attraction of cranberry weevil to its aggregation pheromone blend with and without the addition of E grandlure II and geranic acid. We found that the addition of E grandlure II (a crucial component of the pepper weevil pheromone) significantly reduced the attraction of the pheromone blend and thus acts as an interspecific inhibitor to the cranberry weevil. We also found that adding geranic acid had no detectable effect. The results from this study improves our understanding of pheromone specificity of Anthonomus weevils and will guide future efforts towards optimizing the cranberry weevil aggregation pheromone to improve its field efficacy.

Technical Abstract: The cranberry weevil, Anthonomus musculus Say (Coleoptera: Curculionidae), is a key pest of highbush blueberries (Vaccinium corymbosum L.) and cranberries (Vaccinium macrocarpon Aiton) (Ericaceae) in the northeastern USA. Previously, the A. musculus aggregation pheromone was identified as a blend of (Z)-2-(3,3-dimethyl-cyclohexylidene) ethanol (Z grandlure II), (Z)-(3,3-dimethylcyclohexylidene) acetaldehyde (grandlure III), (E)-(3,3-dimethylcyclohexylidene) acetaldehyde (grandlure IV), and (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol). A related weevil, Anthonomus eugenii Cano (pepper weevil) produces a pheromone blend that includes (E)-2-(3,3-dimethyl-cyclohexylidene) ethanol (E grandlure II) and (E)-3,7-dimethyl-2,6-octadienoic acid (geranic acid) in addition to the A. musculus pheromone components. Here, we conducted field studies in New Jersey and Massachusetts (USA) to test the attraction of A. musculus to its aggregation pheromone blend with and without E grandlure II and geranic acid. We demonstrated that A. musculus adults are less attracted to their aggregation pheromone blend if it contains E grandlure II, though the addition of geranic acid did not affect their response. Our findings indicate that E grandlure II in the A. eugenii pheromone likely acts as an interspecific inhibitor to A. musculus. The results from this study may help guide future efforts towards optimizing the A. musculus aggregation pheromone that could improve its field efficacy.