Abstract: Essential oils of Larix gmelinii (Ruprecht) Kuzeneva fresh needle leaves were extracted by simultaneous distillation extraction(SDE) method with hexane as solvent and analysized by gas chromatography-mass spectrometry(GC-MS).The insecticidal activities of the mixture and pine sawdust wood vinegar on Lymantria dispar 2nd instar larvae were studied.The results showed that the yield of essential oil was 0.93%,and 63 components were identificated with the GC content of 98.11%.The highest GC content compound was 3-carene (12.13%),and the second was 2,4-bis(1-methyl-1-phenylethyl)-phenol (10.71%).The GC content of disparlure,(+)-(7R,8S)-7,8-epoxy-2-methyl-octadecane,was 0.10%.The corrected mortality of five times distilled water of mixture of essential oils of Larix gmelinii fresh needle leaves and pine sawdust wood vinegar(volume fraction 1:9) on Lymantria dispar 2nd instar larvae was 83.33% in 24h by spraying method insecticidal activity experiment.It's better than to that of wood vinegar liquid five times dilution,and it kept invariant for 72 h.The insecticidal activity of pine sawdust wood vinegar was enhanced by mixing with the essential oils.

Key words: Larix gmelinii (Ruprecht) Kuzeneva, essential oil, pine sawdust wood vinegar, Lymantria dispar