2011 Annual Report
1a.Objectives (from AD-416)
Identify chemical attractants (e.g., pheromones/kairomones and plant volatiles) for agriculturally important insect species (either pests or biocontrol agents for weed or insect pests) for which such knowledge is lacking or incomplete, determine the biological and environmental parameters for natural emission of the compounds, and synthesize or otherwise obtain them in quantities sufficient for field use. Characterize the behavioral responses toward the identified compounds under bioassay and field conditions, with special consideration to the development of practical management tools.
1b.Approach (from AD-416)
The overall goals of this proposed research are to identify compounds that are attractive to pest insects and beneficial insects and to develop these semiochemicals into practical applications such as monitoring tools and pest control strategies. The project focuses on insect species for which such information is lacking or incomplete. The target species belong to a diverse group of insects: The emerald ash borer (EAB), Agrilus planipennis, is a severe invasive buprestid pest of ash trees in North America. Host volatiles and essential oils contain several biologically active compounds useful for monitoring EAB. Purification and synthetic methods will be developed to obtain these target compounds in quantities necessary for field experiments. Three exotic parasitoids, Spathius agrili, Oobius agrili, and Tetrastichus planipennis have been released as possible EAB biocontrol agents. Semiochemicals involved in the parasitoid-host-tree complex will be identified focusing first on pheromones as attractants in monitoring the survival and establishment of newly released parasitoid populations. Diorhabda spp. are introduced biocontrol beetles for the invasive weedy tree, saltcedar (Tamarix spp.). Pheromone components for Diorhabda spp. are known, but the precise blend ratios for optimal attractiveness are still incomplete and will be further investigated. The lesser mealworm beetle (LMW), Alphitobius diaperinus is a global insect pest of commercially raised poultry. The pheromone blend of the LMW has recently been identified and can be synergized with poultry manure volatiles. However, knowledge on the correct blend composition is lacking. Optimized blends will be field-evaluated in order to develop a LMW control strategy. Users of the research results would be grower groups, regulatory agencies, land management agencies, businesses dealing with insect attractants, and other scientists.
The emerald ash borer (EAB) is an invasive beetle pest from Asia that is causing widespread mortality of ash trees in the U.S. and Canada. Three species of parasitic Hymenoptera originally reared from EAB in China have been released in the U.S. as possible biological EAB control agents. We have identified the pheromone of one of these parasitic wasps. This natural attractant could be used in monitoring systems to evaluate the establishment and spread of newly released populations of EAB biocontrol agents.
National surveys, performed by federal and state agencies, are to determine the presence of EAB in forests, woodlots, and urban areas. These surveys rely on traps baited with attractants that are placed in still healthy ash trees. The current attractants are based on attractive compounds released by stressed ash trees. Since these attractants are not commercially available they will have to be synthesized. However, synthesis of these compounds is not simple and not without considerable costs. We have confirmed the behavioral function of the earlier identified female-produced sex pheromone in field experiments in the U.S. and Canada. This pheromone could be used to increase the effectiveness of the attractants already in use for the monitoring of EAB.
The lesser mealworm (LMW) beetle has a cosmopolitan distribution. This species has become an important insect pest of commercially raised poultry. USDA, ARS Crop Bioprotection Research Unit scientists at the National Center for Agricultural Utilization Research, Peoria, IL, in collaboration with BASF Corp., are investigating natural attractants for LMW beetles to be used as baits in poultry facilities. The result of these investigations has led to the discovery of male-produced LMW pheromone and several food attractants. These attractants were tested in a wind tunnel bioassay where the beetles have to locate an upwind odor source. The wind tunnel bioassay allows the scientists to test the behavioral activity of potential attractants and optimize attractive blends that can be used in commercial poultry facilities for the control of LMW. A second behavioral bioassay, resembling a simplified poultry facility, is being developed to test LMW attractants in a more life-like environment.
Identification of the female-produced pheromone of the emerald ash borer (EAB). Earlier USDA, ARS Crop Bioprotection Research Unit scientists at the National Center for Agricultural Utilization Research, Peoria, IL, identified the chemical structure of the EAB sex pheromone, but behavioral evidence is needed to confirm the pheromone attractant label. Field studies in the U.S. and Canada, with help from U.S. and Canadian collaborators, confirmed that the sex pheromone is an attractant for EAB. This result will help in the detection of new populations of this destructive ash pest by using the pheromone to pinpoint the presence of EAB populations.
Identification of the male-produced pheromone of Spathius agrili. Spathius agrili is an imported natural enemy of the emerald ash borer (EAB) an invasive beetle pest from Asia that is causing widespread mortality of ash trees in the U.S. and Canada. USDA, ARS Crop Bioprotection Research Unit scientists at the National Center for Agricultural Utilization Research, Peoria, IL, have found a pheromone that works as an attractant for S. agrili. This biocontrol wasp is being released in large numbers throughout all the states that are affected by the EAB infestation. The pheromone will assist in determining the population densities of newly released population of S. agrili, thereby helping forest and woodlot managers in their assessment of EAB biological control.
Petroski, R.J., Vermillion, K., Cosse, A.A. 2011. Two-carbon homologation of aldehydes and ketones to a,ß-unsaturated aldehydes. Molecules. 16(6):5062-5078.
Rooney, A.P. 2011. Pheromone emergencies and drifting moth genomes. Proceedings of the National Academy of Sciences. 18(108):8069-8070.