Abstract:Strobilomyia melaniola (Fan) is the dominant species among the 6 species of maggots damaging larch seed cones in Da Xinganlin, northeastern China.The emergence starts inearly May and lasts until middle of June with peak emergence in mid-May. Ovipositions occurs in late May, 2-3 weeks after supplementary feeding on flowers for newly emerged flies to mature. The examination of cone phenology with development of the fly revealed a close synchrony of the process. Cone water content is found to be amain factor affecting egglaying, whereas larvae enter cones to feed when cone tissues are soft and succulent. Relations of both emergence and oviposition with daily temperature, soil temperature and rain fall are also presented in the paper.