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Final report
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Stink bugs infest numerous cropping systems, causing direct feeding damage to crops, as well as transmitting diseases. Bugs are difficult to sample effectively, and the goal of this project was to develop better methods of monitoring stink bugs, specifically, by using traps baited with pheromone attractants. The pheromone chemicals have been identified, but trap catches in preliminary field tests were low. Consequently, we designed a new type of trap for stink bugs based on what we have observed about the way that bugs respond to their pheromones. These traps worked well in native vegetation but not in field tomatoes, for reasons that are unclear. A different trap design was developed for use in tree crops, based on a screen skirt wrapped around the tree trunk or a major branch, that directed the bug upwards and into the trap. However, this design did not work well, and further development is required. As a second approach to increasing the effectiveness of pheromone-baited traps, we ran experiments to determine whether the attractiveness of the pheromone could be enhanced by mixing it with plant odors of one of stink bugs' favorite hosts, alfalfa. However, concentrations of alfalfa odor spanning three orders of magnitude did not result in any significant increase in attraction of bugs to traps. Our third objective also focused on developing more efficient baits. Specifically, growers do not care which species of stink bug is infesting their crop, because the damage caused by the various species and the methods used to control them are the same. Thus, all a grower cares about is how many stink bugs of all kinds are present in his crop. Thus, we tested whether we could combine the pheromone attractants of several species so that we could attract them all simultaneously. Our results indicate that this will be feasible for at least some species combinations.
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