Abstract: This study examined the EAG (Electroantennogram) responses of Stilpnotia candida to a mix of host plant volatiles and to provide a foundation for the development of plant-derived attractants. During the peak period of adult eclosion, gas chromatography–mass spectrometry analyzed and identified the volatiles emitted by Populus × beijingensis found in Xizang. Based on the preliminary EAG experiments and the GC‒MS results, a blending scheme was developed. EAG and Y-tube-olfactometry were employed to measure the electrophysiological and behavioural responses of unmated males and females 24 h after eclosion 10 blends of volatiles derived from five host plants. The GC–MS analysis revealed 22 volatile compounds from Populus × beijingensis leaves, composed of esters, hydrocarbons, terpenoids, alcohols, phenols, and ether. The results indicated that all 10 blending schemes produced EAG responses in mature S. candida. The concentration thresholds were between 1 and 10 μg·μL^‒1, above the optimal concentration, and a corresponding decrease in EAG was observed. According to intergroup comparisons, mature S. candida had more pronounced EAG responses. Under different concentrations, there were significant differences in the EAG from male and female S. candida to each blending scheme. Behavioural response tests indicated that schemes 2, 7, and 8 exhibited significantly greater attractiveness to adult S. candida. The combined results from the EAG and behavioral response experiments demonstrated that unmated male and female adult S. candida have varying degrees of sensitivity to the volatile compounds from the 10 blending schemes specific to Xizangan Populus × beijingensis. Schemes 2, 7, and 8 showed robust EAG responses and attractive behavioural responses to both male and female adult S. candida.

Key words: Stilpnotia candida, Host volatiles, Gas chromatography-mass spectrometry, Electroantennogram, Y-tube-olfactometer