Abstract:

【Aim】 To clarify the effects of the volatiles from Vigna angularis and V. radiata seeds on the olfactory behavior of adult Callosobruchus chinensis, and to lay a theoretical foundation for the selection of behavioral regulators of C. chinensis. 【Methods】 The volatile compounds from the seeds of V. radiata Jinlv 1 and V. angularis Fenxiaodou 3 were collected and identified by solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Based on the electroantennogram (EAG) and olfactory selective behavioral responses, the compounds and formulations with attractiveness were selected, and field trapping experiments were conducted. 【Results】There were 18 common volatile compounds from V. angularis and V. radiata seeds, mainly including aldehydes, ketones, alkenes, alkanes, alcohols, esters and aromatic hydrocarbons, and the four substances with high content, 6-methylhept-5-en-2-one, hexanal, nonanal and decanal, could cause strong EAG responses in C. chinensis adults, while decane, trans-caryophyllene, 2-methylnaphthalene and cyclohexylbenzene caused relatively weak EAG responses. Olfactory selective behavioral response test showed that hexanal had obviously repellent effects on both female and male adults of C. chinensis, while 6-methylhept-5-en-2-one, nonanal and decanal showed attractiveness to female and male adults of C. chinensis. The results of multi-component laboratory behavioral reaction tests showed that when the mix ratio of 6-methylhept-5-en-2-one and nonanal was 1׃2.6, the selection rates of female and male adults reached more than 70%, indicating relatively better attraction effect. However, the selection rates of female and male adults were not up to 60% when 6-methylhept-5-en-2-one and decanal were mixed in a ratio of 1׃3.2, indicating poor attraction effect. 【Conclusion】 The main volatile compounds of V. angularis and V. radiata, 6-methylhept-5-en-2-one, nonanal and decanal, have good attraction activity against female and male adults of C. chinensis, they may play an important role in the olfactory recognition process of C. chinensis, and can be used to develop behavioral regulators for this pest.

Key words: Callosobruchus chinensis; volatile compounds, electroantennogram, behavioral response, attractant