Effects of Growth and Reproduction of Boring Pests on Volatile Components of Wheat

To find a new way to establish the early warning mechanism of pests,the changes of volatile substances in the process of wheat infestation by pests were investigated in this study. In order to investigate the effects of three main pests on wheat,requiring a density of 10/kg,the wheat volatile components were detected every 30 days. The results showed that 64 kinds of volatile substances were detected after the wheat was attacked by Sitophilus oryzae Linne (rice weevil),77 species of volatile substances were detected after the wheat was attacked by Sitophilus meamais Motschulsky maize weevil,and 69 species of volatile substances were detected after the wheat was attacked by Rhyzopertha dominica. The volatile components of the wheat samples infected with rice weevil,corn weevil and Rhyzopertha dominica were mainly hydrocarbons,alcohols,aldehydes,ketones and esters. With the extension of time,the content of alkanes decreased first and then increased,the content of olefin and ketones increased,the content of aldehydes decreased and the changes of alcohols and esters were not obvious. Olefin and ketone contents showed an overall upward trend,aldehydes content fluctuations decreased,alcohols and esters were relatively insignificant. Sixteen alkanes,nineteen alkanes,nonaldehyde,coconut aldehyde and two iso butyl ester in the volatile components of wheat infected with 3 kinds of moth eating pests decreased obviously. The content of red myrrh and cedenenene in the volatile components of rice and corn elephants showed an upward trend in the volatile components of wheat,and this trend was more obvious in the late stage of infection. The contents of twelve and thirteen alkanes in the volatile components of corn were significantly increased at 60 d.The content of these substances showed a marked change with the storage stability of wheat and these indicators could contributed to predict the quality change of the wheat during storage.