Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2008
Publication Date: 12/15/2008
Citation: Behle, R.W., Cosse, A.A., Dunlap, C.A., Fisher, J., Koppenhofer, A. 2008. Developing Wax-Based Granule Formulations for Mating Disruption of Oriental Beetles (Coleoptera: Scarabaeidae) in Turfgrass. Journal of Economic Entomology. 101:1856-1863. Interpretive Summary: Mating disruption has the potential to provide an environmentally friendly method to control the Oriental beetle, a pest of turf grass, ornamental plants, and berries, if a suitable delivery system can be developed. The chemical structure of the pheromone is well suited for controlled release from wax-based granules. Under laboratory conditions, we showed that manipulating the granule size and pheromone load in soy wax granules produced samples that released pheromone at a level greater than that released by female beetles and by lures used in traps. This basic information is important to support colleagues and industrial partners who are working to develop an economical control product for the Oriental beetle, and for researchers who are striving to develop mating disruption technologies and theories for control of other insect pests.
Technical Abstract: Laboratory experiments were conducted to generate basic information about the volatility of oriental beetle, Anomala orientalis Waterhouse, synthetic mating pheromone, (Z) and (E)-7-tetradecen-2-one, in order to develop wax-based granule formulations to disrupt mating of this pest infesting turfgrass. Rubber septa are used to bait traps to evaluate treatments in field experiments; therefore, septa impregnated with pheromone were evaluated as well. Rubber septa loaded with 10, 100, and 300 micrograms/septa provided steady rates of pheromone release (zero-order) over 4 weeks of evaluation (total = 1.1, 9.0, and 26.9 micrograms/4 weeks, respectively). Septa with 1,000 micrograms/septa had a significant decline in the rate of pheromone release for this 4-week exposure time (total = 119 micrograms/4 weeks). A proprietary wax granule (25% w/w pheromone in granules weighing 0.044 gram/granule provided steady rate of pheromone release (total = 2347 micrograms/4 weeks/granule) that exceeded the rate of rubber septa. Experimental granules were made by dripping molten soywax and pheromone solutions into a pan granulator of excess perlite. Experimental granules (0.016 gram/granule made of soywax with higher pheromone loads (10% w/w) approached zero-order release (steady state) (total = 69 micrograms/4 weeks/granule) while smaller granules (0.004 gram/granule with less pheromone (0.1% w/w) provided first-order release profiles (decreasing rate with longer exposure time) (total = 0.35 micrograms/4 weeks/granule). A field trial demonstrated the potential of granular formulations to provide effective mating disruption as measured by trap shutdown for up to 4 weeks where turfgrass was treated. Documenting pheromone release profiles for these experimental granules and rubber septa provides valuable information that will support future field evaluations of mating disruption as a control strategy.