松大蚜Cinarasp.数量变动的初步探讨

初步研究结果表明,松大蚜种群数量在一年内有两次明显的变动。春季虫口数量最多,但初孵若蚜在迁移过程中造成大量死亡,保存率并不高。夏季虫口急剧下降,甚至达到难以找到的程度;秋季虫口回升,但总量远不及春季。研究初步认为夏季高温是影响虫口急剧减少的主要因素。对林间若蚜数量的调查分析,表明其在林中呈负二项式分布。已知天敌有食蚜蝇、瓢虫、草蛉、蚜茧蜂、褐蛉、粉蛉、蜘蛛等。以食蚜蝇、瓢虫、草蛉为主,食蚜蝇的作用最大。

PRELIMINARY REPORT ON A STUDY OF THE POPULATION DYNAMICS OF THE PINE BIG APHIS (CINARA SP. )

This preliminary study showed that two distinct changes occured in the population of pine big aphis within one year.The largest population of this aphis appeared in the spring season,but preservation rate was low,because death rate of young nymphs in first intar was very high in migration.In Summer its population dropped down rapidly,sometimes it was difficult to find,population increased again in Autumn,but was far less than that in Spring.Right temperature in Summer is assumed to be the main factor for the fall in population.By analysis of a numerical survery of the nymphs it was discovered that the destribution of Cinara sp on the trees was of negative binomial type.Many species are knewn to be natural enemies of Cinara sp.,they are,Syrphid flies,lady beetles,green lacewings,small parasitic wasps and spiders,among these,lady beetles,greenwings and Syrphid flies are more important in control of aphis population,especially the last one,co-worker in 1980,co-worker in 1981,