Abstract:  【Aim】 Protaetia brevitarsis is an economically important agricultural insect pest in China. This study aims to identify volatile compounds from apple, grape and corn under two states (healthy and damaged by P. brevitarsis adults) that elicit electrophysiological responses in antennae of female adults of P. brevitarsis. 【Methods】 Fruit volatiles from three fruits, apple, grape and corn, were collected by dynamic headspace adsorption technique. The active compounds in fruit volatile samples were screened by gas chromatography-electroantennogram detection (GC-EAD) technique and further identified by gas chromatography-mass spectrometry (GC-MS) analysis. All EAD-active compounds were quantitated by internal standard method. The active volatile compounds released by healthy and P. brevitarsis damaged fruits were evaluated by principal component analysis (PCA) and cluster analysis (CA). 【Results】Twentythree, 23 and 25 volatile compounds from apple, grape and corn, respectively, were found to be able to trigger EAD responses in female adults of P. brevitarsis. The volatile compounds in six treatments were divided into five groups by CA based on PC1 and PC2, which originated from healthy apple, damaged apple, healthy grape+damaged grape, healthy corn and damaged corn, respectively. There existed apparent differences in the main volatile components among the three fruits. As compared to heathy fruits, damaged fruits released significantly lower amounts of seven esters (2-methylbutyl acetate, propyl 2-methylbutyrate, amyl acetate, methyl hexanoate, butyl butyrate, hexyl acetate and hexyl isovalerate), but significantly greater amounts of three alcohols (2-methylpropanol, 2-methylbutanol and cis-3-hexenol). 【Conclusion】 The volatile compounds from the three fruits that trigger significant EAD responses of adult P. brevitarsis are mainly alcohols and esters. Damage by P. brevitarsis causes significant increase in contents of most alcohols and decrease in contents of esters. The attractiveness of the 58 EAD-active compounds identified in this study needs to be assayed by further laboratory and field experiments.

Key words: Protaetia brevitarsis, apple, grape, corn, fruit volatiles, gas chromatography-electroantennographic detection