Effects of synthetic methyl salicylate and natural herbivore induced plant volatiles on aphids and predators in bean plants

Abstract

Methyl salicylate (MeSA), which is released by plants after herbivore attack, not only attractant effect on natural enemies but also effect behaviour of pest arthropods. These compounds release by plants which is named herbivore induced plant volatiles (HIPVs). In this study, the population of aphids and predators in synthetic MeSA applied and mite infected bean plants in order to naturally stimulate MeSA, linalol etc. release were investigated. This study was conducted in field conditions with three replicates and following treatments MeSA alone, MeSA+mite release, mite release and untreated control in both year 2011 and 2012. Vials include 2 ml MeSA were used in every plot and renew every week. Randomly selected 15 bean leaves from each plot were examined under stereomicroscope and aphids and predators were counted. In 2011 and 2012, aphid abundance of Control (0.76 +/- 0. 04; 2 +/- 0.2) and mite release (0.67 +/- 0.08; 0.17 +/- 0.02) plots were higher than MeSA (0.1 +/- 0.02; 0) and mite release+MeSA (0.1 +/- 0.02; 0.17 +/- 0.02) plots. In 2011 coccinellids were high in MeSA plots, Orius sp. and syrphids were high in mite release+ MeSA plots. In this study MeSA is not only repellent effect on aphids but also attractant effect on predators and improve the effectiveness of natural enemies in field. In future, MeSA could be used for the support of biological control against aphids in plant protection.