Entomologia Experimentalis et Applicata (2009) 130, 215-221

Yong Liu, Wan-Lei Wang, Guang-Xi Guo and Xiang-Long Ji (2009)
Volatile emission in wheat and parasitism by Aphidius avenae after exogenous application of salivary enzymes of Sitobion avenae
Entomologia Experimentalis et Applicata 130 (3), 215-221
Abstract: Enzymes in the saliva of the English green aphid, Sitobion avenae (F.) (Homoptera: Aphididae), may be responsible for inducing indirect defence in wheat. In this study, we examined the effects of exogenous application of three salivary enzymes of S. avenae, namely, polyphenol oxidase, pectinase, and cellulase, on the release of volatiles from wheat and the attractiveness of these volatiles to the parasitoid Aphidius avenae Haliday (Hymenoptera: Aphidiidae). In greenhouse experiments, parasitism of S. avenae on plants surrounded by pectinase-treated plants and aphid-damaged plants was significantly higher than parasitism of aphids on plants surrounded by cellulase- and polyphenol oxidase-treated plants. In Y-tube olfactometer tests, female A. avenae significantly preferred the volatiles collected from pectinase-treated plants and aphid-damaged plants. Gas chromatography-mass spectrometry analysis showed that two kinds of semiochemicals, sulcatol and sulcatone, were identified only in pectinase-treated plants and aphid-damaged plants. In field experiments, parasitism of S. avenae by A. avenae was significantly higher on plants sprayed with a mixture of sulcatol and sulcatone than parasitism on plants sprayed with volatiles collected from cellulase- and polyphenol oxidase-treated plants. These results show that pectinase in S. avenae watery saliva can trigger wheat plant indirect defence, and play a crucial role in interaction between wheat, wheat aphid, and A. avenae.
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Link to article at publishers website
Database assignments for author(s): Yong Liu

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
resistance/tolerance/defence of host
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Sitobion avenae	Wheat (Triticum)
Aphidius picipes (parasitoid)	Sitobion avenae	Wheat (Triticum)