Chemical Ecology of Chestnut Weevils and Other Agroforestry Pests
Chestnut weevils are the single greatest threat to the commercial growth of the emerging chestnut industry. Historically, chestnut weevils have destroyed entire chestnut harvests. In the Midwest United States, the most important chestnut weevil species is Curculio sayi, the lesser chestnut weevil. There are no effective means of monitoring the weevils' dispersal and orientation behaviors. Without a reliable monitoring technique to 
determine adult chestnut weevil emergence and their movement into and out of the orchards, chestnut growers will be unable to determine economic injury levels to nuts and if and when a chemical control tactic should be implemented. The overall goal of this research project is to establish some biological data regarding the chemical ecology of weevils towards chestnut plant volatiles (such as orientation mechanisms and preferences). Some overall objectives include: (1) identifying the major volatile components of chestnut; (2) evaluating adult chestnut weevil behavioral responses to plant volatiles (such as through wind tunnel and Y-tube olfactometer bioassays); and (3) to evaluate adult chestnut weevil physiological responses, through electroantennagraphy (EAG), to chestnut volatiles in order to provide a more comprehensive view of the chestnut weevil's relationship to its host tree.
Sublethal Effects of Ecdysone Agonists on Tortricid Moth Biology
Tebufenozide and methoxyfenozide belong to a novel class of insect growth regulators, bisacylhydrazine ecdysteroid agonists, that mimic 20-hydroxyecdysone and induce a premature, lethal molt, especially in lepidopterous larvae. Most previously reported studies have examined the effects of these compounds on the larval (target) stage, with very lit
tle having been published that examined the effects of adult exposure to these compounds. The overall goal of this project was to determine what effects adult exposure to ecdysone agonists would have on some major tortricid moth pest reproduction and sexual attractiveness and responsiveness. The moth species examined during this project have been the codling moth (Cydia pomonella), oriental fruit moth (Grapholita molesta), redbanded leafroller (Argyrotaenia velutinana) and obliquebanded leafroller (Choristoneura rosaceana).
Some key results from these studies are:
- When adult moths are exposed to treated surfaces, continuously or for only 24 h, significant reductions in mean fecundity and fertility occurred.
- Depending on moth species, exposure to methoxyfenozide affected mean reproduction through both emale and male exposure.
- Treated males were less responsive to calling females as were nontreated males, and that exposure to treated surfaces affected male responsiveness more so than female attractiveness.
- In the field, untreated female moths were more attractive to nontreated wild male moths that treated females, and that wild males exposed to treated tree surfaces were significantly less responsive to sex pheromone traps than were nontreated wild males.