Parasitoid Coccobius azumai is an important biological agent against Hemiberlesia pitysophilahzd pine armored scale imported from Japan in the late 1980s and released in Fujian pine forest of China. This paper analyzed the dispersal ability, post-release parasitic ratio and the driving factors of parasitoid population using a series of observations in selected pine forests in Fujian Province of China for the period 2007-2009. The parasitoid population dispersed much slowly in the field and spread at an approximate velocity of 200 m per year. Even though jerk dispersal of the population was occasionally observed in the field experiment, generalized linear model analysis showed that a displacement dispersal trend which increased with the time of release. The interaction of forest stand and dispersal time significantly influenced population dispersal. High parasitoid release initially, ♀:♂=7: 1 mixture and release in the upper/middle forest slopes enhanced population dispersal. Linear regression analysis revealed that C. Azumai parasitic ratio on H. Pitysophila adult females significantly decreased with increasing distance from parasitoid population dispersal site. Parasitic ratios were 41.8%, 34.7%, 19.8%, 11.0% and 3.8% for initial release intervals of 0, 50 m, 100 m, 150 m and 200 m, respectively. No significant effects of the number of initial release and sex-mix pretreatment were observed on parasitic ratio at 100 m site. It suggested that interaction of high pest-controlling efficiency and low dispersal capability of parasitoid population was disadvantageous to parasitoid stability and sustaining in the field. The long-term efficient control was not sustainable for present releases in small geographic ranges. An effectively considerable measure was to release parasitoids at greater number of sites with reasonable spatial intervals in large geographic ranges, and periodically do so at logical time intervals. In order to fully utilize the parasitoids, useful and detailed methods of release were suggested, involving spatial layouts of release sites, complementary releases, parasitoid collection modes, initial released number and sex-mix pretreatment.%为充分利用花角蚜小蜂控制松突圆蚧,通过3年的野外定位观察,研究了其扩散能力,扩散后寄生率及其影响因素.结果表明:花角蚜小蜂扩散力弱,1年约扩散200m,在林间可跳跃式扩散,但其扩散距离总体上随时间延长而增大,林分条件和时间的交互作用也对其扩散有极显著影响；较大的初始放蜂量、7∶1的雌雄配比预处理、在中坡或上坡放蜂等有利于其扩散.放蜂1年后花角蚜小蜂对松突圆蚧雌成蚧的寄生率随扩散距离增大而显著降低,在放蜂点及与其相距50m、100m、150m和200m处的寄生率分别为41.8%、34.7%、19.8%、l 1.0%和3.8%；初始放蜂量和雌雄配比对该蜂扩散至100 m处的寄生率未见明显影响.这说明,花角蚜小蜂较强控害作用和较弱扩散力相互作用的结果不利于其野外种群的稳定,依赖局部放蜂难以实现对松突圆蚧的持久控制,而大面积、空间间隔合理的多点放蜂、时间间隔的有序补充放蜂是一条值得考虑的途径.最后,就放蜂点布局、补充放蜂、蜂源采集、初始放蜂量和放蜂的雌雄配比等方面提出了完善花角蚜小蜂利用措施的建议.
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