Fine‐tuning the composition of the cranberry weevil (Coleoptera: Curculionidae) aggregation pheromone

Abstract

The cranberry weevil Anthonomus musculus Say is a key pest of highbush blueberries (Vaccinium corymbosum L.) and cranberries (Vaccinium macrocarpon Aiton) in the northeastern United States. Previous studies have reported A. musculus adult attraction to traps baited with the aggregation pheromone of the pepper weevil Anthonomus eugenii Cano, likely because these two weevils share similar pheromone blends that differ only in two components. The A. musculus aggregation pheromone contains (Z)‐2‐(3,3‐dimethylcyclohexylidene) 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); whereas A. eugenii produces a pheromone blend that includes (E)‐2‐(3,3‐dimethylcyclohexylidene) ethanol (E grandlure II) and (E)‐3,7‐dimethyl‐2,6‐octadienoic acid (geranic acid) in addition to the four A. musculus pheromone components. Here, we hypothesized that differences in pheromone composition between these two species influence A. musculus adult attraction to its aggregation pheromone. To test this, we studied the response of A. musculus to its pheromone blend with and without E grandlure II and geranic acid, a commercial A. eugenii pheromone lure and a no‐lure control in highbush blueberry and cranberry fields in New Jersey and Massachusetts, respectively. Regardless of crop type, A. musculus adults were more attracted to their four‐component pheromone blend and the blend plus geranic acid than the commercial A. eugenii pheromone and the no‐lure controls. The A. musculus pheromone blend plus E grandlure II and the A. eugenii pheromone blend also captured more A. musculus adults than the no‐lure control but not compared to the commercial A. eugenii pheromone. Further analysis showed that A. musculus adults are significantly (~27%) less attracted to their pheromone blend if it contains E grandlure II, although the addition of geranic acid did not affect their response. These findings may help guide future efforts towards the development of behaviour‐based tools to monitor and manage A. musculus.

Identification of sex-specific compounds in the invasive four-eyed fir bark beetle Polygraphus proximus

“…Several species of Anthonomus weevils also use (Z)-DMCHE, (Z)-DMCHA and (E)-DMCHA as parts of their aggregation pheromones. In these beetles, species-specificity seems to be achieved by different relative abundances of the pheromone components or by species-specific compounds such as grandisol, (E)-DMCHE or lavandulol, which are necessary for attraction in some species and repellants in other species (Tumlinson et al 1969;Eller et al 1994;Szendrei et al 2011;Innocenzi et al 2001;Rodriguez-Saona et al 2020). A similar situation is seen in the bark beetles Pityogenes quadridens and Pityogenes bidentatus, whose pheromone blends are similar but where (E)-DMCHE, chalcogran and grandisol are species-specific pheromone components which repel one species from the pheromone blend of the other (Byers et al 2013).…”

Advances in cranberry insect pest management: A literature synthesis

“…As a result, new methods of pest control needed to be developed, such as target-specific and more environmentallysustainable chemical control classes with different modes of action (Rodriguez-Saona et al, 2016) (Figure 3). Additionally, behavioral control methods, such as mating disruption, have been evaluated (Figure 3), with newer technologies allowing for better identification of pheromones of cranberry insect pests (Rodriguez-Saona et al, 2020a). Furthermore, there has been increasing research on biological and natural control, particularly on the use of entomopathogenic nematodes for soil insect pests (Hayes et al, 1999;Koppenhöfer et al, 2008;Ye et al, 2018;Foye and Steffan, 2019).…”

“…Other known insect pheromones, but not widely used, are those for A. musculus (Szendrei et al, 2011;Rodriguez-Saona et al, 2020a), C. parallela (Polavarapu and Lonergan, 1998), C. topiaria (Dixon and Hillier, 2005), D. oxycoccana (Fitzpatrick et al, 2000), the cranberry blossomworm, Epiglaea apiata Grote (Lepidoptera: Noctuidae) (Zhang and Polavarapu, 2003), Hoplia equina LeConte (Coleoptera: Scarabaeidae) Weber et al, 2005), the white grub Phyllophaga georgiana Horn (Coleoptera: Scarabaeidae) (Robbins et al, 2009), and the cranberry root grub, Lichnanthe vulpina Hentz (Coleoptera: Scarabaeidae) (Robbins et al, 2006). There are many potential reasons for their limited use, including their cost, lack of efficacy, and limited availability due to the narrow distribution of the pest.…”

“…There are many potential reasons for their limited use, including their cost, lack of efficacy, and limited availability due to the narrow distribution of the pest. For example, the major components of the A. musculus aggregation pheromone have been identified and evaluated using yellow sticky cards in cranberries (Szendrei et al, 2011;Rodriguez-Saona et al, 2020a); yet, the pheromone blend remains inefficient and needs improvement, likely because additional components might be missing. Populations of D. oxycoccana that live on blueberries (Vaccinium corymbosum L.) are theorized to have a different sex pheromone than those that subsist on cranberries (Cook et al, 2011;Fitzpatrick et al, 2013), which might mean that the two populations are cryptic species (Cook et al, 2011;Cook et al, 2012); however, the high cost of pheromone production might challenge their use for monitoring D. oxycoccana populations (Fitzpatrick et al, 2013).…”