4.2. Indicator volatile compounds
The volatile compounds found by comparing samples infested and non-infested by several insect species are shown in Table 1 (chromatogram of R. dominica used as example, see Fig. 6). The volatiles were generally identified as esters, aldehydes or hydro- carbons. As for S. oryzae, the indicator volatile compounds could not be detected by this method as there was no difference between infested and non-infested samples so they were excluded from sensitivity determination (Section 3.4)