Host associated behavior, ecology, and fitness of the plum Curculio conotrachelus nenuphar (Coleoptera: Curculionidae) in peach and blueberry

Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae) is a frugivorous weevil native to eastern North America. In most of its range, it is considered an oligophagous species, mainly utilizing Rosaceous tree fruit as feeding and oviposition hosts. However, in the mid-Atlantic region of the United States, C. nenuphar is also considered a significant pest of the Ericaceous host blueberry. Using blueberry as an oviposition site is a behavior only sporadically observed in the rest of C. nenuphar’s range. It was not known if this blueberry-utilizing population was behaviorally or physiologically distinct from the broader tree fruit-utilizing group, nor was it known if C. nenuphar host choice was mediated by natal host fidelity or preference-performance relationships. In this research, I compare these two groups’ behavior and development on different hosts. Our results show that New Jersey C. nenuphar in peach and blueberry disperse similarly, by moving from a wooded edge into the field interior, however C. nenuphar in peach may spend more time in the orchard border and move between the border and interior more freely. This behavioral observation may have implications for integrated pest management based on targeted insecticide applications. Behavioral and physiological results show that C. nenuphar exhibits some host fidelity to collected hosts. Both host groups preferred the odor of their collected host in olfactometer experiments, and both preferred to oviposit in that host when given a choice. When given no choice, blueberry C. nenuphar were able to utilize peach or blueberry equally well as oviposition sites. Peach C. nenuphar however, laid significantly fewer eggs on blueberry, even when no other host was available. Blueberry C. nenuphar larvae were found to have high fitness in either host, performing as well in peach as in their collected blueberry. However, peach C. nenuphar acted in accordance with the preference-performance hypothesis, experiencing a significant decrease in their larvae’s fitness when attempting to use blueberry as an oviposition host and avoiding it commensurately. Overall, our observations validated the hypothesis that blueberry and peach C. nenuphar are behaviorally and physiologically distinct in terms of host preference and larval survival but behaved similarly in their dispersal into hosts. In this thesis, we discuss these results, as well as the evolutionary implications thereof.Ph.D.Includes bibliographical reference