Journal of Chemical Ecology

, Volume 31, Issue 8, pp 1733–1746

Methyl Salicylate, a Soybean Aphid-Induced Plant Volatile Attractive to the Predator Coccinella septempunctata

Article

DOI: 10.1007/s10886-005-5923-8

Cite this article as:
Zhu, J. & Park, KC. J Chem Ecol (2005) 31: 1733. doi:10.1007/s10886-005-5923-8

Abstract

Induced volatiles provide a signal to foraging predatory insects about the location of their prey. In Iowa, early in the growing season of soybean, Glycine max, many predacious seven-spotted lady beetles, Coccinella septempunctata, were observed on plants with heavy infestations of soybean aphid, Aphis glycines. We studied whether the attraction of this beetle is caused by the release of specific volatile compounds of soybean plants infested by aphids. Volatile compounds emitted by soybean plants infested by aphids were compared with those of undamaged, uninfested, and artificially damaged plants. Gas chromatography–mass spectrometry analyses revealed consistent differences in the profiles of volatile compounds between aphid-infested soybean plants and undamaged ones. Significantly more methyl salicylate was released from infested plants at both the V1 and V2 plant growth stages. However, release patterns of two other induced plant volatiles, (d)-limonene and (E,E)-α-farnesene, differed between the two plant growth stages. Gas chromatographic–electroantennographic detection of volatile extracts from infested soybean plants showed that methyl salicylate elicited significant electrophysiological responses in C. septempunctata. In field tests, traps baited with methyl salicylate were highly attractive to adult C. septempunctata, whereas 2-phenylethanol was most attractive to the lacewing Chrysoperla carnea and syrphid flies. Another common lady beetle, the multicolored Asian lady beetle, Harmonia axyridis, showed no preference for the compounds. These results indicate that C. septempunctata may use methyl salicylate as the olfactory cue for prey location. We also tested the attractiveness of some selected soybean volatiles to alate soybean aphids in the field, and results showed that traps baited with benzaldehyde caught significantly higher numbers of aphids.

Key Words

Glycine maxsoybean volatileinduced plant volatilemethyl salicylateattractionenhanced biological controlseven-spotted lady beetleAphis glycines

Copyright information

© Springer Science + Business Media, Inc. 2005

Authors and Affiliations

  1. 1.MSTRS Technologies, Inc.AmesUSA
  2. 2.Department of EntomologyIowa State UniversityAmesUSA
  3. 3.Department of EntomologyPennsylvania State UniversityUniversity ParkUSA