Exploring an odor-baited “trap bush” approach to aggregate Plum curculio (Coleoptera: curculionidae) injury in blueberries

Authors: RODRIGUEZ-SAONA, C - Rutgers University; NIELSEN, A - Rutgers University; Shapiro Ilan, David; TEWARI, S - Corteva Agriscience; KYRYCZENKO-ROTH, V - Rutgers University; FIRBAS, N - Rutgers University; Leskey, Tracy

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/2/2019
Publication Date: 4/19/2019
Citation: Rodriguez-Saona, C., Nielsen, A., Shapiro Ilan, D.I., Tewari, S., Kyryczenko-Roth, V., Firbas, N., Leskey, T.C. 2019. Exploring an odor-baited “trap bush” approach to aggregate Plum curculio (Coleoptera: curculionidae) injury in blueberries. Insects. 10(4):113. https://doi.org/10.3390/insects10040113.
DOI: https://doi.org/10.3390/insects10040113

Interpretive Summary: Plum curculio is a key insect pest in various perennial fruit crops including apples, pears, peaches, plums, cherries and blueberries. The insects are generally controlled using broad spectrum chemical insecticides. However, due to environmental and regulatory concerns, reduction in chemical insecticide usage is needed. Research toward alternative control measures is warranted. In previous research conducted in apples, a “trap-tree” approach was used to substantially reduce the amount of pesticides applied to the crop. In the trap-tree approach, a natural chemical attractant is used to lure the majority of plum curculio to selected trees on the perimeter of the orchard. These sentinel trees are then sprayed with insecticides thereby killing off the bulk of the pests and protecting the interior of the orchard. Insecticide usage is substantially reduced because relatively few trees are sprayed per acre. In this study, we determined whether the trap-tree (or more appropriately, trap-bush) approach could be utilized in a blueberry cropping system. The trap-bush method was tested in four commercial orchards in comparison with plots without trap-bushes. The results indicated that plum curculio aggregate when presented with trap-bushes in blueberry fields. Therefore, odor-baited trap bushes can be used in blueberries to manipulate plum curculio movement behavior, i.e., to aggregate adult insects, without compromising injury in field interiors. As a result, insecticides could be targeted only to a few (perimeter-row) bushes within fields rather to entire fields and the total amount of insecticide used will be greatly reduced.

Technical Abstract: This 2-year (2013–2014) study assessed the efficacy of an odor-baited “trap bush” approach to aggregate plum curculio, Conotrachelus nenuphar, adult injury, i.e., number of oviposition-scared fruit, in four commercial highbush blueberry farms in New Jersey (USA). In each farm, we compared fruit injury in bushes baited with grandisoic acid and benzaldehyde along the perimeter of trap-bush plots versus unbaited bushes in control plots. We also measured the amount of fruit injury in neighboring bushes (i.e., spillover effect) and in the plots’ interior. In both years, the amount of fruit injury by C. nenuphar adults was greater on and near odor-baited bushes in trap-bush plots compared with those on and near unbaited bushes in control plots, indicative of aggregation. Injury in unbaited bushes neighboring trap bushes was often greater than unbaited bushes in control plots, providing some evidence for a spillover effect. However, no difference in fruit injury was found between interior trap-bush and control plots. These results suggest that odor-baited trap bushes can be used in blueberries to manipulate C. nenuphar adult foraging behavior, i.e., aggregate adults, without compromising injury in field interiors. Thus, insecticides could be targeted only to a few (perimeter-row) bushes within fields rather to entire fields.