|Giacomuzzi, Valentino - Free University Of Bozen-Bolzano|
|Cappellin, Luca - Harvard University|
|Khomenko, Iuliia - Fondazione Edmund Mach|
|Biasioli, Franco - Fondazione Edmund Mach|
|Schutz, Stefan - Gottingen University|
|Tasin, Marco - Swedish University Of Agricultural Sciences|
|Angeli, Sergio - Free University Of Bozen-Bolzano|
Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2017
Publication Date: 12/1/2017
Citation: Giacomuzzi, V., Cappellin, L., Khomenko, I., Biasioli, F., Schutz, S., Tasin, M., Knight, A.L., Angeli, S. 2017. Emission of volatile compounds from apple plants infested with Pandemis heparana larvae, antennal response of conspecific adults, and preliminary field trial. Journal of Chemical Ecology. 42:1265-1280.
Interpretive Summary: Effective, low-cost monitoring of tree fruit pests is an important component of developing integrated programs which can minimize the use of insecticides. Researchers at the USDA, ARS, Yakima Agricultural Research Laboratory, Wapato, WA in collaboration with researchers at Free University of Bozen, Bolzano, Italy characterized the volatiles released by apple damaged by insect larvae. A subset of these chemicals were tested in the field and two compounds in combination with acetic acid were attractive for both moth sexes of an important moth pest of orchards in Europe that is now introduced into North America. 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: This study investigated the volatile emission of apple foliage that were either uninjured, mechanically-injured, or exposed to larval feeding by Pandemis heparana (Lepidoptera: Tortricidae). Volatiles were collected by closed-loop-stripping-analysis and characterized by gas chromatography-mass spectrometry in three time periods: after 1 hour and again 24 and 48 hours later; and continuously with proton transfer reaction – time of flight-mass spectrometry (PTR-ToF-MS) over a 72-h period. In addition, the volatile samples were analyzed by gas chromatography-electroantennographic detection (GC-EAD) using male and female antennae of P. heparana. Twelve compounds were detected from uninjured foliage compared with 23 from mechanically-injured, and 30 from P. heparana-infested foliage. Interestingly, six compounds were only released by P. heparana-infested foliage. The emission dynamics of many compounds measured by PTR-ToF-MS showed striking differences according to the timing of herbivory and the circadian cycle. For example, the emission of green leaf volatiles began shortly after the start of herbivory and increased over time independently from the light-dark cycle. Conversely, the emission of terpenes and aromatics showed a several-hour delay in response to herbivory and followed a diurnal rhythm. Methanol was the only identified volatile showing a nocturnal rhythm. Consistent GC-EAD responses were found for sixteen compounds, including five aromatics. A field trial in Sweden demonstrated that phenylmethanol, 2-phenylethanol, phenylacetonitrile, and indole lures placed in traps were not attractive to Pandemis spp. adults, but 2-phenylethanol and phenylacetonitrile when used in combination with acetic acid were attractive to both sexes.