Seasonal Activity of Plum Curculio (Coleoptera: Curculionidae) in Southeastern Peach Orchards

Authors: TZU-CHIN, LIU - University Of California, Riverside; Cottrell, Ted; BLAAUW, BRETT - University Of Georgia

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/14/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Plum curculio is a key pest in Southeastern peach orchards when it infests fruit and decreases yield. In Northeastern apples, plum curculio was found to have an “edge effect”, where more plum curculio are present next to a forested border than in the center of an orchard, and that flying or walking depended on air temperatures. Studies investigated whether plum curculio in Southeastern peach orchards exhibit the edge effect and whether they primarily walk or fly to host trees. We found that plum curculio do not show an edge effect in Southeastern peaches. Additionally, plum curculio in Southeastern peaches did not exhibit a primary mode of movement and the numbers of flying plum curculio and walking plum curculio were not significantly correlated in the field. These results emphasize that using plum curculio monitoring tools that only capture either flying or walking plum curculio might not be ideal for plum curculio sampling in the Southeast. Overall, our findings indicate that plum curculio in Southeastern peaches and Northeastern apples do not exhibit the same behaviors.

Technical Abstract: Plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), is a key pest in Southeastern peach production by infesting fruit and decreasing yield. In Northeastern apples, plum curculios were found to have an “edge effect”, where more plum curculio are present next to a forested border than in the center of an orchard, and that their propensity to fly or walk depended on air temperatures. We conducted field studies over three seasons (2019 to 2021) to investigate whether plum curculio in Southeastern peach orchards exhibit the edge effect and determine their primary mode of movement (flying or walking). Our results revealed that plum curculio did not exhibit the edge effect in Southeastern peaches. Thus, unlike Northeastern apples where plum curculio exhibit the edge effect, the reduced-input application program where insecticide sprays mainly target a few perimeter-row trees instead of the whole orchard for plum curculio management is not recommended for Southeastern peaches. Additionally, we observed that plum curculio in Southeastern peaches did not exhibit a primary mode of movement, and in most of the sampling weeks, the numbers of flying plum curculio and walking plum curculio were not significantly correlated in the field. These results emphasize that using plum curculio monitoring tools that can only capture either flying or walking plum curculio might not be ideal for plum curculio sampling in the Southeast. Overall, our findings indicate that plum curculio in Southeastern peaches and Northeastern apples do not exhibit the same behavior (i.e., edge effect and propensity to fly or walk).