Electroantennogram and behavioral responses of Agrilus mali to the volatiles from Malus sieversii trees induced by pest and disease

Abstract

Objective This study aims to explore the electroantennogram and behavioral responses of Agrilus mali to the volatiles from Malus sieversii trees in different damaged states to provide reference for the research and development of highly effective attractants. Method The volatiles were collected by using dynamic headspace adsorption from branches and limbs of M. sieversii trees. Result There are total of 46 volatile compounds in 9 categories has been obtained, including alcohols, lipids, aldehydes, alkanes, alkenes, ketones, terpenes, ethers and others. Compared with healthy branches, the relative contents of eicosane and pentadecane increased in A. mali damaged branches, while the relative contents of 8 volatiles such as butenol, 2-methylacrolein, heptadecane, heneicosane, cycloheptatriene, cyclohexanone, α-pinene and chamomile decreased. Fourteen compounds were added such as cis-3-hexenol, hexanal, decanal, nonanal, (+)-limonene etc. In Valsa mali damaged branches, pentadecane, heptadecane, 3,7-dimethyldecane, eicosane and α-pinene increased, and heneicosane, cyclohexanone, cycloheptatriene, azulene decreased. Twelve compounds were added such as cis-3-hexenol, butyl butyrate, hexanal, (+)-α-pinene, (+)-limonene, etc. Compared with the volatilides released from healthy limbs, the relative contents of cis-3-hexenol, α-pinene, (−)-α-pinene and camphene were increased in A. mali damaged limbs, and hexanal, cycloheptane, β-pinene, cycloheptatriene, azulene contents decreased. Seventeen compounds were added such as 3-octene-2-alcohol, butyl butyrate, decanal pentadecane, (+)-aromadendrene, etc. In Valsa mali damaged limbs, hexanal increased, and cis-3-hexenol, acrolein, cyclohexanone, α-pinene, (−)-α-pinene, β-pinene and azulene decreased. Eleven compounds were added such as benzaldehyde, pentadecane, dipentene, etc. EAG responses and behaviour of A. mali towards volatiles released by host were tested. The results showed that strong EAG reactants could be produced in the antennae of male and female adults of A. mali, these compounds were (−)-α-pinene, nonanal, (+)-α-pinene, benzaldehyde, decanal, butyl acrylate. A. mali were attracted by (−)-α-pinene, α-pinene, (+)-β-pinene, β-pinene, decanal, nonanal in the behavior bioassay. Conclusion According to the results of EAG responses and behavioral orientation, the (−)-a-pinene, nonanal and decanal had good attraction to the adult of Agrilus mali.[Ch, 1 fig. 3 tab. 27 ref.]