Project Overview

Reports

Commodities

• Fruits: peaches

Target Pests

Practices

• Pest Management: behavioral control, competition, pesticide resistance management, precision pesticide use, traps

Plum curculio, Conotrachelus nenuphar (Herbst) (PC) is a key insect pest in Southeastern peach production that infests fruit and significantly decreases yield. Currently, there is a lack of IPM approaches for PC management in the Southeast. As a result, peach growers mainly follow the calendar-based spray programs and heavily rely on repeated applications of conventional broad-spectrum insecticides with up to 12 sprays per season for this one pest (Foshee et al. 2008, Akotsen?Mensah et al. 2011). However, frequent broad-spectrum insecticide applications can cause insecticide resistance issues, non-target effects (e.g. eliminating pollinators) and detrimental effects on the environments and human health. Previous research in Northern apples has shown that insecticide input could be greatly reduced by adopting the “attract-and-kill” technique where insecticide applications focused only on the apple trees baited with PC attractants (i.e. an apple volatile—benzaldehyde and the PC aggregation pheromone—grandisoic acid) instead of the entire apple orchard (Leskey et al. 2008). With an efficient attractant, plum curculios are attracted and aggregated on the particular baited trees, so that insecticide applications can precisely target and kill the pest on the baited trees. However, the attract-and-kill technique is still unavailable for Southeastern peaches, because the efficient PC attractants are unavailable. Thus, there is a need to look into the correlation between PC infestation trends and the variations of volatile emissions from peach fruit and foliage at different peach developmental stages throughout a growing season. Knowing this correlation can not only help identify potential peach volatiles as PC attractants for the attract-and-kill technique, but also predict PC infestations based on the peach developmental stages.   

The long-term goal of our project is to facilitate the development of PC IPM programs for Southeastern peaches where insecticide use is reduced by adopting the attract-and-kill technique and conducting insecticide applications that coincide with PC infestations instead of relying on the traditional calendar-based schedule. The objectives of the proposed study are (1) to identify the volatiles that peach fruit and foliage emit at different peach developmental stages throughout a growing season and (2) to investigate PC infestation trends at different peach developmental stages throughout the growing season. Although previous research has identified the volatile compounds emitted from harvested peach fruit and foliage by conducting gas chromatographic analyses, and studies have also shown that PC exhibits varied levels of attraction to different fruit volatiles in laboratory tests, previous studies did not investigate the variations of peach volatile emissions throughout a growing season or monitor the PC infestations corresponding to those volatile emissions in peach orchards (Kemp et al. 1971, Spencer et al. 1978, Horvat et al. 1990, Leskey et al. 2001). Thus, we will weekly collect peach fruit and foliage volatiles by enclosing fruit or foliage with non-absorbent bags and vacuuming out the volatiles for gas chromatographic analyses. In addition, while collecting peach volatiles in the orchards, we will monitor PC infestations by assessing the PC oviposition scars on the fruit, or sampling PC abundances on the trees by jarring the tree branches when the fruit is present yet early in the season.

By the completion of the proposed project, we will obtain the knowledge of the correlation between PC infestation trends and the variations of volatile emissions throughout a peach growing season. Based on the findings of our research, future research can not only develop PC attractants for the attract-and-kill strategy, but also design novel insecticide spray programs where insecticide applications better coincide with PC infestations, and thus prevent excessive insecticide use. Overall, the proposed study will provide the pest information needed for enhancing the development of future PC IPM programs in southeastern peaches.