2012 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. This highly cryptic insect is detected in the field with the use of traps baited with natural attractants (e.g. ash tree volatiles), which are placed in ash trees. Chemical control of the beetles is not feasible due to the large area involved (15 U.S. states and 2 Canadian provinces). However, biological control with natural enemies might be more successful. Three species of none-stinging parasitic wasps, originally reared from EAB in China, have been released in the U.S. as possible biological EAB control agents.
Earlier on we have identified the pheromone of EAB, and together with scientists from the Canadian Forest Service and Animal and Plant Health Inspection Service (APHIS), we now have demonstrated that very small amounts of this pheromone mixed together with a single ash volatile compound is highly attractive to adult EAB insects in the field. This newly developed attractant mixture could be a more cost efficient and more attractive alternative to the current ash oils that are used in the national survey programs.
Tools are needed in order to determine if newly released parasitic wasps have been established in the field release areas. Earlier we have identified the pheromone of one of the three imported parasitic wasps, which can be used as a monitoring tool. This natural attractant could be used in monitoring systems to evaluate the establishment and spread of newly released populations of EAB biocontrol agents. We now have identified the pheromone of a native parasitic wasp that has adapted to EAB as a host and populations of this wasp have seen a dramatic increase in Michigan over the last few years. This new pheromone attractant can be used to follow its progress as a native natural enemy of EAB and check if populations of this native parasitoid also exist in other U.S. states.
New chemical attractants for the detection of the Emerald Ash Borer. Sex pheromones (chemicals produced by insects to attract mates) are needed in pest management programs to detect, track, and monitor insect populations. The emerald ash borer (EAB) is an invasive insect pest that is causing severe damage to ash trees in North America. ARS scientists in the Crop Bioprotection Research Unit in Peoria, IL, identified the EAB sex pheromone and showed that it can be mixed with a chemical produced by ash trees to make a highly effective attractant for adult EAB insects. In addition, this newly developed attractant mixture is more cost-efficient than the ash oils that are currently used. As a result, efforts to detect and control EAB populations will be greatly improved.
New tools to harness biocontrol agents of the Emerald Ash Borer. The emerald ash borer (EAB) is an invasive beetle pest from Asia that is causing widespread mortality of ash trees in the United States. Methods to control this major insect pest are urgently needed. Spathius floridanus is a newly discovered natural enemy of the EAB that is native to the United States and a potential biocontrol agent for the EAB. However, tools are needed to detect and subsequently monitor populations of this species if it is to be successfully developed as a biocontrol agent. ARS scientists in the Crop Bioprotection Research Unit in Peoria, IL, have found a pheromone that works as an attractant for this species. This pheromone, as well as other chemical attractants developed by researchers in Peoria, will be used to track S. floridanus in the field and monitor its effectiveness in controlling EAB infestations.
Rooney, A.P., Xue, B., Roelofs, W.L. 2012. Genome-wide screening and transcriptional profile analysis of desaturase genes in the European corn borer moth. Insect Science. 19:55-63. DOI: 10.111/j.1744-7917.2011.01427.x.
Cosse, A.A., Petroski, R.J., Zilkowski, B.W., Vermillion, K., Lilito, J.P., Cooperband, M.F., Gould, J.R. 2012. Male-produced pheromone of Spathius agrili, a parasitoid introduced for the biological control of the invasive emerald ash borer, Agrilus planipennis. Journal of Chemical Ecology. 38(1):389-399.
Crook, D., Khrimian, A., Cosse, A.A., Frazer, I., Mastro, V. 2012. Influence of trap color and host volatiles on capture of the emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae). Journal of Environmental Entomology. 105:429-437.