1a. Objectives (from AD-416):
The ultimate goal of this research is to utilize behaviorally-based technologies originally developed for plum curculio (PC) in apples as a model system for PC in other fruit crops including peaches and blueberries, and to develop similar approaches for another temperate weevil, the cranberry weevil (CBW) in blueberries. We will: 1) Isolate and identify candidate olfactory stimuli associated with host- and mate-finding for CBW using headspace volatile collections, gas chromatography coupled with electro-antennogram detection (GC-EAD) and mass spectrometry (GC-MS). We expect to refine, both qualitatively and quantitatively, components of the CBW pheromone and host-plant volatile cues to optimize field efficacy by testing additional, possibly synergistic, chemical cues; 2) Optimize effective deployment strategies for known PC and novel CBW olfactory stimuli including both attractants and repellents to manipulate host- and mate-finding behavior, and promote aggregation of adults within spatially precise locations within peaches (PC) and blueberries (PC, CBW). In addition, we will evaluate a push-pull approach using a combination of attractant and repellent stimuli for PC. We expect to develop methods to optimize deployment of attractants and repellents to better time insecticide sprays in the field; 3) Evaluate efficacy of combinations of multiple management approaches for optimal weevil control in fruit crops. We expect to develop novel multi-component strategies for weevil control in peach and blueberries, including: a) an attract-and-control approach consisting of a combination of behavioral and reduced-risk chemical tactics (PC and CBW), b) a combination of behavioral and biological (entomopathogenic nematodes) control tactics (PC), and c) a combination of all three approaches (behavioral, chemical, and biological) (PC); 4) Actively promote outreach and information exchange among interested stakeholders, crop consultants, state IPM research and extension programs, and federal researchers. We will disseminate information about the semiochemical-based monitoring and management technologies in fact sheets, bulletins, websites, scientific publications, and at grower and scientific meetings.
1b. Approach (from AD-416):
We will utilize an ‘attract and kill’ strategy developed for PC in apples, i.e. the baited trap tree strategy, to manage PC in peaches and blueberries, and CBW in blueberries. We will include promising strains of entomopathogenic nematodes to target larval stages and use only reduced risk insecticides to manage adults.
3. Progress Report:
Ths project addresses two historically problematic, multi-regional temperate weevil pests of fruit crops, the plum curculio (PC) and the cranberry weevil, with the ultimate goal of developing, evaluating, and implementing novel low-risk multi-tactic strategies to monitor and manage these pests, and promoting long-term sustainable IPM in multiple fruit crops in the U.S. We will optimize effective deployment strategies for known PC olfactory stimuli including both attractants and repellents to determine if the successful attract-and-kill strategy for PC in apple, known as the trap tree approach, can be translated to other crops attacked by this insect, namely peach and blueberry. To date, begun to measure the degree of aggregation that occurs in peach canopies and blueberry bushes baited with two key attractants, the fruit volatile benzaldehyde and the PC aggregation pheromone, grandisoic acid. We have seen moderate aggregation so far and plan to continue these studies over the course of several field seasons. We also will target adults with insecticides demonstrating curative activity against eggs and adults, and evaluate entomopathogenic nematode strains previously identified as effective against PC larvae in apple orchards.