[目的]明确危害我国青岛地区3种针叶树的害虫是松针鞘瘿蚊Thecodiplosis japonensis,研究其形态特征、危害特点及扩散方式,以期为该虫的发生监测及防治提供理论基础.[方法]对采自黑松Pinus thunbergii和赤松P.densiflora上瘿蚊的卵、幼虫、蛹及成虫进行观察、拍照和比对.制做玻片观察幼虫剑骨片的形态特征.用扫描电子显微镜观察幼虫头部表面超微结构.提取其基因组DNA,利用通用引物扩增线粒体细胞色素氧化酶亚基Ⅰ(COⅠ)序列并测序,与NCBI数据库中已有序列比对.统计受害枝中单枝瘿瘤数量及每瘿瘤内幼虫数量,计算针叶被害率和每瘿瘤幼虫数目的相关性.观察交配、产卵行为并持续记录其生活史.[结果]老熟幼虫剑骨片和成虫翅脉的形态特征均符合Thecodiplosis japonensis的描述;基于COⅠ基因序列构建邻接法系统发育树(NJ树)显示,山东青岛瘿蚊样本与日本T.japonensis样本聚成一支,置信度为100％,明确了外来入侵种松针鞘瘿蚊已在我国山东黄岛地区定殖.目前该虫主要危害黑松Pinus thunbergii、赤松P.densiflora和油松P.tabulaeformis,幼虫在当年生松针基部为害形成虫瘿并在其中取食,使松针停止生长,而导致被害针叶较健康针叶显著缩短,逐渐枯黄脱落.[结论]本文首次明确在黄岛区危害3种松树树种的针叶造瘿类害虫为松针鞘瘿蚊,描述其生物学特性及危害特征.DNA比对结果对开发松针鞘瘿蚊分子快速鉴定技术提供依据,为疫情的早期监测提供理论基础和参考.“,”[Objectives] This study was to identify the pest attacking three pine species in Qingdao being Thecodiplosis japonensis,and to study its morphological characteristics,distribution and damage characteristics to provide references for its monitor, control and prevention. [Methods] The eggs, larvae, pupae and adults of T. japonensis on Pinus thunbergii and P. densiflora in Shandong province were observed, photographed and compared. The morphological characteristics of sternal “Y”shaped spatula of the mature larvae were observed. The head ultrastructure of the mature larvae was observed by scanning electron microscopy. The genomic DNA was extracted and amplified by the universal primers. The sequence of the mitochondrial cytochrome oxidase subunit I (CO ) was sequenced and compared with the sequence in the NCBI databaseⅠ . The number of attacked needles and larvae per gall of each collected branches were counted, the correlation between the damage rate of the needles and the number of larvae per gall was calculated. Observe mating and oviposition behavior, and record its life history continuously. [Results] The morphological characteristics of sternal “Y” shaped spatula of the mature larvae and wing veins of adults were consistent with the description of T. japonensis. Neighbor-Joining phylogenetic tree was built based on the CO gene sequences, and the result indicated that specimen from Qingdao were gathered in the sameⅠbranch with T. japonensis from Japan, with the bootstrap value of 100％. It is clear that the alien invasive species T. japonensis has been colonized in Huangdao area of Shandong province. T. japonensis attack P. thunbergii, P. densiflora and P. tabulaeformis mainly. Galls were formed by larvae feeding at the base of the needle in the current-year shoots. Infested needles stopped growing and becoming shorter than normal, and then withered and died gradually. [Conclusion] We proved that the pest damaging three pines in Huangdao district was T. japonensis, and described its biological characteristics in details. These results could provide references for the rapid identification of T. japonensis, and would provide the theoretical basis and reference for early monitoring.