Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/13/2017
Publication Date: 3/17/2017
Citation: Giacomuzzi, V., Mattheis, J.P., Basoalto, E., Angeli, S., Knight, A.L. 2017. Survey of conspecific herbivore-induced volatiles from apple as possible attractants for Pandemis pyrusana (Lepidoptera: Tortricidae). Pest Management Science. doi:10.1002/ps.4548. Interpretive Summary: Characterizing the compounds released by plants can help in the discovery of new insect pest attractants that can improve management for growers. Researchers at the USDA, ARS, Yakima Agricultural Research Laboratory, Wapato, WA in collaboration with researchers at Free University of Bozen, Bolzano, Italy and the USDA, ARS Laboratory in Wenatchee, WA have characterized the volatiles released by intact and larval-infested apple and then field-tested various chemical combinations to identify new attractants for both moth sexes of Pandemis pyrusana, an important moth pest of orchards in western U.S. Information from this research supports the continued effort to develop even more effective lures that can be used in trap-based monitoring program for important moth pests in tree fruits.
Technical Abstract: Studies were conducted to identify volatiles released by apple, Malus domestica Borkhausen, foliage subjected to herbivore feeding. The volatiles released upon herbivore attack could be attractive to adult leafroller, Pandemis pyrusana Kearfott when combined with acetic acid. First, volatiles released from intact foliage untreated or sprayed with a commercial formulation of Aureobasidium pullulans (de Bary) and from treated and untreated foliage with actively-feeding larvae were collected by dynamic air entrainment and characterized by gas chromatography-mass spectrometry. The most abundant volatiles released following herbivore-feeding were four green leaf volatiles (GLVs) and acetic acid. Nineteen volatiles were found to be released in significantly higher amounts from foliage with herbivore damage than from intact leaves, including GLVs, aromatics, terpenes, (Z)-jasmone, and acetaldehyde. Application of A. pullulans to intact foliage significantly increase the release of benzaldehyde and benzyl alcohol. The combination of spraying the yeast followed by sustained herbivore injury significantly increased the levels of methyl salicylate and phenylacetonitrile compared with herbivory alone. Levels of acetic acid were not significantly different among treatments. When the aromatics were tested in combination with acetic acid, only phenylacetonitrile and 2-phenylethanol caught similar and significantly more total and female moths than acetic acid alone. The addition of either (E)-4,8-dimethyl-1,3,7-nonatriene, (E)-ß-ocimene, or (Z)-3-hexenyl acetate to traps baited with acetic acid and either 2-phenylethanol or phenylacetonitrile did not increase moth catches. Moth catches in traps baited with acetic acid and one of 12 apple volatiles were not significantly higher than in traps with acetic acid alone, and were always significantly lower than in traps with acetic acid and 2-phenylethanol. We propose that the combination of acetic acid and either aromatic volatile is attractive to both sexes of P. pyrusana as a cue for food resources available for adult feeding.