Submitted to: Environmental Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/20/2012
Publication Date: 6/30/2012
Citation: Ryall, K.L., Silk, P.J., Mayo, P., Crook, D., Khrimian, A., Cosse, A.A., Sweeney, J., Scarr, T. 2012. Attraction of agrilus planipennis fairmaire (Coleoptera: Buprestidae) to a volatile pheromone: effects of release rate, host volatile and trap placement. Environmental Entomology. 41(3):648-656. Interpretive Summary: Insect pests cause a significant damage to crops and forest, and monitoring their populations aids greatly to reducing the pesticide use and biological control. Monitoring the exact whereabouts of the invasive emerald ash borer beetle, currently destroying millions of ash trees in fifteen US states and two Canadian provinces, is difficult due to the large infested area, the relative tall trees, and smallness of the beetle. Attractant-baited traps have been used to monitor insect pest populations for a wide range of insect species, both in agricultural as well as in forestry settings. In the present study, we use field trapping as a technique to further investigate the behavioral responses of the emerald ash borer to the sex pheromone of this insect, alone and in combination with a volatile compound identified from the ash foliage. The results demonstrated that this combination of attractants can be used as a sensitive tool for detecting the presence of the emeralds ash borer in forests and urban wood lots. As such, the developed attractant might help in the control of this very destructive ash pest insect. The results of this study are of interest to entomologists and chemists involved in the research of potential pest control compounds, and to State and Federal agencies involved in monitoring and controlling emerald ash borer.
Technical Abstract: Attraction of emerald ash borer, Agrilus planipennis Fairmaire, to a volatile pheromone was demonstrated in three field experiments using baited green sticky traps. A dose-response curve was generated for male A. planipennis to increasing release rates of (3Z)-dodecen-12-olide, (3Z)-lactone, in combination with the green leaf volatile, (3Z)-hexenol. Only the lowest release rate (<2.50 µg/day) of (3Z)-lactone significantly increased captures of male A. planipennis. Effect of trap height, (3Z)-lactone, and (3Z)-hexenol and their interactions on the trap capture of A. planipennis was determined in a factorial experiment. Number of males per trap was significantly and positively affected by (3Z)-lactone, (3Z)-hexenol, and trap height whereas number of females per trap was affected by trap height only; none of the interactions were significant. As predicted, the greatest mean catch of males was in traps baited with (3Z)-lactone and (3Z)-hexenol placed high in the canopy. Electroantennogram tests on the bark volatile, 7-epi-sesquithujene, demonstrated the ability of male and female A. planipennis antennae to detect and respond to this compound, particularly the (+)-7-epi-sesquithujene isomer. Results from an olfactometer bioassay and field testing did not demonstrate attraction of either males or females to (+)-7-epi-sesquithujene but the field trapping experiment confirmed attraction of male A. planipennis to (3Z)-lactone. These data increase our understanding of the pheromone ecology of the invasive emerald ash borer, provide further confirmation of the behavioral activity of the female-produced lactone pheromone, and should increase the ability to detect A. planipennis infestations where they are present