Location: Subtropical Horticulture Research2013 Annual Report
1a. Objectives (from AD-416):
1. Find semiochemicals that lead to products for detection, behavioral disruption, attraction to insecticidal baits, or surveillance of redbay ambrosia beetle, tephritid fruit flies, cocoa pod borer, and other pests that threaten food security. 2. Test novel quarantine treatments for phytosanitary applications on imported and exported fruit or other commodities. 3. Develop practical systems for integrated pest management that reduce the threat of importation of exotic pests from foreign tropical and subtropical environments.
1b. Approach (from AD-416):
Research will consist of field and laboratory experiments to determine the behavior, chemical ecology of and novel quarantine treatments for insect pests that can be used in the development of control techniques. Strategies will include the development of new detection and delimitation tools, use of biosafe insecticides in baits and discrete feeding stations, and discovery of components in the insect's biology that can be exploited for formation of control measures for exotic insect pests that affect plant production.
3. Progress Report:
Chemical analysis of avocado mapping population study for potential marker-assisted breeding of avocado cultivars resistant to redbay ambrosia beetle. Studies were continued to quantify the terpenoid content of parent and progeny avocado trees, specifically the chemicals suspected to be attractants for the redbay ambrosia beetle. The goal of this research is to identify the variation of amounts of attractive chemicals, to link this information to the genetic map that is being developed by collaborators at SHRS as part of a marker-assisted breeding program for pest-resistant avocado cultivars for commercial production. Laboratory and field tests of sugar baits for caribflies. Laboratory wind tunnel tests and field tests are ongoing to test the effect of age on fermenting sugar baits on attraction of caribflies. This study follows research conducted previously that determined EAG response of female caribflies to these baits. This information will be used to identify new attractants for caribflies. Field tests of synthetic lures for pest drosophilid fruit flies. Field tests are ongoing to test synthetic lures for pest the drosophilid African fig fly. Field tests were conducted to test combinations ten chemicals identified from wine and vinegar that have been found to be successful for other pest drosophilids. Results of this research may lead to development of a synthetic lure for detecting new infestations of this pest or monitoring established populations. EAG analysis of medfly response to synthetic chemicals identified from essential oils. Laboratory studies are ongoing to quantify EAG response of sterile male medflies to five chemicals identified from plant essential oils. These oils have been found to be attractive to sterile and wild medflies in laboratory and field trials conducted previously. Field and laboratory evaluations of cubeb bubble lure for redbay ambrosia beetle (RAB). Comparative research with plant essential oils identified cubeb oil as a new attractant for RAB (see accomplishment below). Tests are ongoing to evaluate a commercially available formulation of cubeb oil (bubble lure). These tests will include (1) field trials to determine efficacy and longevity of cubeb bubble lures relative to manuka and phoebe oil lures, (2) volatile collections followed by gas chromatography-mass spectroscopy to quantify lure emissions over time, and (3) electrophysiology studies to assess RAB olfactory responses.
1. Identification of cubeb oil as an improved attractant for RAB. RAB is a recently established wood-boring beetle that vectors laurel wilt, a lethal disease of avocado and other trees in the Lauraceae. No RAB pheromones have been identified to date, and the current monitoring tool (manuka oil lure) is suboptimal due to short field life (2-3 weeks in Florida). Improved lures are critically needed for early detection of this invasive pest. ARS scientists (Miami, FL) conducted a series of field and laboratory tests to evaluate attraction and EAG responses of RAB to seven plant essential oils, including manuka. Of the oils evaluated, cubeb oil (an extract from berries of Piper cubeba) showed the most promise as a new attractant for RAB. In initial field trials, the commercial cubeb bubble lure captured significantly more RAB than the commercial manuka lure, and was effective for detection of RAB for at least 8 weeks.
Niogret, J., Epsky, N.D., Schnell, E.Q., Schnell, R.J., Heath, R., Meerow, A.W., Kendra, P.E. 2013. Analysis of sesquiterpene distributions in leaves, branches, and trunks of avocado (Persea americana Mill.). American Journal of Plant Sciences. Am. J. Plant Sci. 4 (4): 922-931.