Abstract: 【Aim】 This study aims to clarify the types of antennal sensilla and electrophysiological responses of the adult Galeruca daurica to volatiles of host plants, so as to provide the necessary basis for further investigation on the mechanism of chemoreception in G. daurica. 【Methods】 The sensilla types on the antennae of G. daurica adults were observed using scanning electron microscopy (SEM). The volatiles were collected from the host plant Allium mongolium by headspace dynamic adsorption collection method, and the main components of volatiles were determined by GC-MS. The electrophysiological responses of G. daurica adults to the main volatile components of this host plant were determined by electroantennogram (EAG). 【Results】 There are five types of sensilla on the antennae of G. daurica adults, including sensilla trichodea (ST), sensilla chaetica (SC), sensilla basiconica (SB), sensilla campaniformia (SCa) and Bhm bristles (BB). Thirty-two volatile components were identified from A. mongolium. Among them, sulfur compounds accounted for 49.3%. EAG results showed that six compounds including diallyl sulfide, diallyl disulphide, (Z)-2-hexen-1-ol, 2-hexenal, methyl benzoate, and hexanal elicited relatively strong eletrophysiological responses in female adults of G. daurica, while only diallyl disulphide and 2-hexenal elicited relatively strong EAG responses in male adults. Moreover, most of the tested compounds elicited stronger EAG responses in female adults than in males. At the concentration of 1 mol/L, the tested six compounds except 2-hexenal could elicit the strongest EAG response in G. daurica adults. 【Conclusion】 Six compounds of A. mongolium can elicit strong EAG response of G. daurica adults, including diallyl sulfide, diallyl disulphide, (Z)-2-hexen-1-ol, 2-hexenal, methyl benzoate, and hexanal. The EAG responses of G. daurica adults to all these compounds except 2-hexenal increase with increasing concentrations.

Key words: Galeruca daurica; antennal sensilla, Allium mongolium, volatile, electroantennogram