Abstract: 【Aim】 Insect cuticular hydrocarbon profiles have been actively studied in insect chemotaxonomy. Liquid injection with solvent is commonly used technique for extraction and sample introduction. This study explored an easier and simpler extraction and sample introduction technique using solid injection. We discussed the feasibility of the technique in rapid identification of fruit flies. 【Methods】The cuticular hydrocarbon profiles of adult Bactrocera dorsalis (Hendel) were compared using thermal separation probe (TSP) (a solid phase injection device) and a liquid injection technique. Then the cuticular hydrocarbon profiles from head, thorax, abdomen, forewings, and legs of the fruit fly using solid injection were compared with those from the whole body extracts using liquid injection. Finally the cuticular profiles of the adult specimen preserved for various time periods were analyzed. 【Results】 The results showed that cuticular hydrocarbon components obtained from adult wing using solid injection (39 components) were higher than those obtained using liquid injection (36 components). The quantities of cuticular hydrocarbons from both wings and legs obtained using solid injection were 0.18-23.37 and 0.03-4.13 ng/μg, respectively. They were extremely significantly higher than those obtained using liquid injection (0.05-3.93 and 0.01-0.68 ng/μg from wings and legs, respectively) (P<0.01). The hydrocarbon amount from the wings was significantly higher than that from the legs (P<0.01). The detection sensitivity for cuticular hydrocarbon analysis using solid injection was 1.7-10.8 times as high as that obtained using liquid injection. The cuticular hydrocarbon composition of wings, legs, and thorax using solid injection was similar to that of whole body using liquid injection. Specimens preserved for 30 d in desiccator were not significantly different from fresh specimens in the composition and content of wing hydrocarbons (P>0.05). However, the compositions of wing hydrocarbons from specimens preserved for 30, 60 and 150 d were significantly different (P<0.05). 【Conclusion】 Solid injection technique can be used as an alternative method for cuticular hydrocarbon analysis of B. dorsalis, and adult wing is a good sampling part for the solid injection method. It is more sensitive than liquid injection method. The technique provides the technical basis for rapid identification of fruit flies during border inspection and quarantine.

Key words: Bactrocera dorsalis, solid injection, liquid injection, wings, cuticular hydrocarbons