Location: Subtropical Horticulture Research2010 Annual Report
1a. Objectives (from AD-416)
The long-term objective of this project is to develop trapping and control components and systems for integrated pest management of exotic pest insects in the Caribbean, Central and South America that pose a threat to U.S. agriculture.
1b. Approach (from AD-416)
Research will consist of field and laboratory studies to determine the life history, distribution and host range of exotic insect pests; to identify semiochemicals; and to conduct studies on the behavioral and physiological roles of semiochemicals on these pests and associated biocontrol organisms. Strategies will include development of attractant-based technologies and systems for detecting, delimiting and monitoring exotic pest insects, and for establishing and enhancing management programs for these insects.
3. Progress Report
Relationship between physiological age and fruit fly antennal response to 3-methyl-1-butanol. SHRS scientists previously found that 3-methyl-1-butanol (MB) is attractive to female caribflies in laboratory bioassays. MB is a volatile chemical emitted from bacteria, a food source for adult flies. Research was conducted to quantify caribfly antennal response to MB, including dose response curves, potential additive effects with known attractants, and effect of fly age on antennal response. Unlike other food-based attractants, MB was found to elicit a consistently high antennal response regardless of female physiological state. Field tests will be conducted to determine if this high antennal response to MB is correlated with increased capture of caribflies when deployed in traps with known attractants. Field tests of mass trapping and bait stations for Caribfly population suppression. The second year of an ongoing study tested a new version of the caribfly bait station that had an improved visual cue and an increased attractant release rate. The greatest suppression of adult fly numbers was obtained in the mass trapping treatment, and fruit from that block had the lowest level of larval infestation. The block with the improved bait station also had fewer adults trapped than the untreated control, but larval infestation was not reduced. Response of sterile male medflies to rasped bark from several host and non-host trees. Studies were initiated to test response of male medflies to chemicals from bark rasped from avocado trees that contain chemicals reported to have a strong behavioral effect. Sterile males were used for these studies. Response to bark from four avocado genotypes was compared with response to bark from two trees reported to show high level and low level short-range attraction for males. Response to the four avocado varieties was intermediate, and correlated with EAG response to the six types of bark. Chemical analysis is ongoing to identify semiochemicals responsible for medfly response. Behavior of male medflies in response to exposure to plant essential oils. Studies were initiated to test response of male medflies to plant essential oils. Response to previously untested essential oils, including essential oils used in traps for the redbay ambrosia beetle, was compared with response to essential oils previously reported to have strong behavioral effects on males. Short-range attraction bioassays using sterile males were used to determine optimal dose for each oil. Long-range attraction was tested with flight cage tests using sterile males, using different trap and lure dose combinations. Parallel field tests were conducted in Honduras under an SCA to test response of wild medflies. Chemical analysis is ongoing to identify semiochemicals responsible for medfly response. Field evaluation of two lures and two trap types for capture of redbay ambrosia beetle. Forest entomologists identified manuka oil and phoebe oil as baits for monitoring the redbay ambrosia beetle (RAB). Our initial field tests suggested that phoebe oil was more attractive than manuka oil and research has been initiated to evaluate efficacy.
1. Attraction of redbay ambrosia beetle to host wood and essential oil lures. The redbay ambrosia beetle (RAB) is the vector of laurel wilt, a lethal vascular disease of avocado that seriously threatens the avocado industry. Development of attractant-based trapping systems for this pest is a critical need for both growers and regulatory agencies. ARS Researchers at Miami, FL, conducted laboratory and field tests to compare attraction of RAB to bolts of wood from avocado with attraction to manuka lures and phoebe lures (two types of essential oil lures recommended for this pest). There was no strong preference among avocado cultivars representative of the three horticultural races, and RAB preferred to bore into cut/wounded surfaces of host wood. RAB captures with phoebe lures were comparable to captures with host wood, but captures with manuka lures were very low. This information has been used by action agencies in their monitoring programs to improve detection and monitoring for this important new pest.
Heath, R.R., Vazquez, A., Schnell, E.Q., Kendra, P.E., Epsky, N.D. 2009. Dynamics of pH modification of an acidic protein bait used for tropical fruit flies (Diptera: Tephritidae). J. of Econ. Entomol. 102(6):2371-2376.