1a. Objectives (from AD-416):
1) Identify behaviorally active semiochemicals for invasive insect species such as the coffee berry borer and the coconut rhinoceros beetle and other invasive pests to be determined in collaboration with cooperator. 2) Synthesize the pheromones and other semiochemicals as needed and validate attractiveness in lab and field bioassay. 3) Identify optimal ways to utilize identified behaviorally active semiochemicals such as early detection and/or mass-trapping. 4) Develop systems approaches against fruit flies that allow movement from quarantine areas.
1b. Approach (from AD-416):
Our approach is to collect authentic pheromones from live ‘calling’ females and/or clipped abdominal tips and or plant kairomones from host plants and using headspace collection and or tip extraction to identify the chemicals present using GC-MS. Electrophysiological studies will be employed to identify biologically active constituents using GC-EAD on insect antenna. Those with activity will be tested and formulated for testing in a flight tunnel bioassay or other laboratory apparatus and if possible in the field. Next the pheromone and/or semiochemical will be synthesized and lures used to conduct field evaluations. Specifically, we would like to correlate capture of targeted invasive species to field populations and damage levels in the different cropping systems unique to Hawaii. Lastly we hope to use semiochemicals in potential control tactics. Identify and deploy systems approaches for fruit flies.
3. Progress Report:
The goal of the project is identification and field use of semiochemicals of invasive pests in Hawaii which directly contributes to objective 2 of the in-house project, "Identify attractants from host and non-host plants and determinephysiological and environmental factors affectivng or modulating pest behavior". We have continued our studies on identification of semiochemicals for invasive insect pests in Hawaii. Behavioral studies on coconut rhinoceros beetle suggest that compounds from coconut may be behaviorally active and might be used in combination with the aggregation pheromone in the field. Headspace trapping from coconut trees and soil mulch is continuing as well as electroantennogram studies of the beetle antenna. Our studies on coffee berry borer has focused on headspace identification and electroantennogram evaluation of volatile components from fresh and dries coffee cherries, bark, leaves and beetles. Beetles have been found to respond to several compounds identified in headspace trapping of volatiles. The work is being replicated and repeated to ensure consistency of the response. We have also been looking at behavior of beetles to coffee berries of different ripeness to determine what differences if any exist in the volatile profiles and behavior of beetles. Studies have resumed on the identification of additional semiochemicals from little fire ant in Hawaii and improving the trap for this invasive pest. We have completed the studies on tomato forced infestation. Our results suggest that green tomatoes are poor host of Mediterranean fruit fly but that infestability increases with increased ripeness of tomatoes. However commercially harvested green tomatoes do not seem to be a significant risk in trade. We are also evaluating a new semiochemical lure that may be attractive to Queensland fruit fly based on earlier evaluations.