Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/27/2015
Publication Date: 11/27/2015
Publication URL: http://handle.nal.usda.gov/10113/61700
Citation: Cooper, W.R., Horton, D.R. 2015. Effects of elicitors of host plant defenses on pear psylla (Cacopsylla pyricola: Psyllidae). Entomologia Experimentalis et Applicata. 157:300-306.
Interpretive Summary: Pear psylla is the key insect pest of pear in the United States. This insect is primarily controlled using insecticides, and ongoing research seeks to discover new ways to manage this pest. Defense elicitors are foliar treatments which activate plant defenses leading to broad-spectrum immunity to numerous pests. Scientists at the USDA-ARS laboratory in Wapato, Washington tested the effects of three elicitors of plant defenses against pear psylla. They found that the commercial elicitors, Actigard, Employ, and ODC each reduce numbers of pear psylla by altering adult preference and increasing nymph mortality. These results suggest that defense elicitors may be useful tools for the control of pear psylla in commercial pear orchards.
Technical Abstract: Pear psylla, Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae), is a key pest of cultivated pear (Pyrus communis L.) in North America and Europe. We examined the effects of foliar applications of three commercially available chemical elicitors of host-plant defenses, Actigard, Employ, and ODC, on survival, development, feeding, and egglaying of C. pyricola. All three defense elicitors reduced the number of nymphs present on Bartlett or D’Anjou pear 30 days after releasing 10 adults on the trees. Choice assays showed that females settled and oviposited on untreated trees more often than on trees treated with any of the three defense elicitors. Results of no-choice assays confirmed that the effects of Actigard, Employ, and ODC on C. pyricola were due to activation of systemic plant responses that led to reduced oviposition preference and nymph survival. However, results did not provide evidence that plant responses to elicitors led to reduced nymphal feeding rates or development. Results of our laboratory studies suggest that commercial