环境对皖西大别山皱鞘双条杉天牛发生的影响

Influence of environmental factors on the occurrence of Semanotus bifasciatus sinoauster in Dabieshan Mountains of Western Anhui Province

皖西大别山林区 4月月候气温在 18 6～ 2 0 6℃时 ,皱鞘双条杉天牛Semanotusbifasciatussinoauster (Gressitt)卵孵化率为 74 74 %～ 82 35 %。通过抚育管理的纯林 ,每hm2 在 390 0株以下的 8a～ 16a生林分 ,抽样林分平均种群密度在 0 4 6头以下 ,有虫株率为 0 33%～ 14 5 0 % ,未抚育管理的纯林种群密度每株在 1 1头～ 1 6 1头、有虫株率为 2 1 6 7%～ 2 6 83%。而混交林极少 。

The results showed that the hatching rate of Semanotus bifasciatus sinoaustereggs was between 74.74% and 82.35% when the temperature in April was between 18.6 ℃ and 20.6 ℃?In the tending pure forests,the stands with (3900) trees or less at the age of 8-16 per hectare were sampled,the average population density of the pest was below 0.46 per tree and the attacking rate ranged from 0.33% to 14.50%.In the pure stands without tending the population density was from 1.10 to 1.61 per tree and the attacking rate ranged from 21.67% to 26.83%.But there were few in the mixed forests.