后斑小瓢虫对竹茎扁蚜的控害潜能

Control Potential of the Predator Scymnus(Pullus) posticalis(Coleoptera: Coccinellidae) against Pseudoregma bambusicola(Homoptera: Hormaphididae)

【目的】通过室内测定后斑小瓢虫[Scymnus（Pullus）posticalis（Coleoptera：Coccinellidae）]对竹茎扁蚜[Pseudoregma bambusicola（Homoptera：Hormaphididae）]的最佳捕食密度、最大捕食量、干扰系数、瞬时攻击率、处理时间等参数,研究后斑小瓢虫对竹茎扁蚜的控害潜能,通过后斑小瓢虫生命表的测定,探明利用竹茎扁蚜饲养后斑小瓢虫的种群增长趋势,为开发利用后斑小瓢虫防治竹茎扁蚜提供科学依据。【方法】在温度（23±1）℃,相对湿度70%~73%条件下,采用塑料盒定时定量饲养观察方法测定后斑小瓢虫对竹茎扁蚜的捕食功能,测试后斑小瓢虫自身密度的干扰效应;使用DPS软件,分别用Holling-Ⅱ型、汪世泽Holling-Ⅲ型功能反应新模型和金开正捕食者-猎物功能反应统计模型等昆虫生态学方法进行拟合,分析后斑小瓢虫对竹茎扁蚜的最佳捕食密度、最大捕食量、干扰系数、瞬时攻击率、处理时间等参数,研究后斑小瓢虫对竹茎扁蚜种群的调节作用;通过在林间设置纱网笼罩饲养法测定后斑小瓢虫实验种群生命表,研究后斑小瓢虫内禀增长力等种群数量特征。【结果】在实验室特定条件下,捕食功能反应测定得出后斑小瓢虫3龄幼虫和成虫对竹茎扁蚜平均日捕食量最大可达75头和81头,表明后斑小瓢虫3龄幼虫和成虫对竹茎扁蚜具有较强的捕食能力;后斑小瓢虫自身密度的干扰效应测定结果反映,后斑小瓢虫释放比例为1∶38.8时可以达到最大的控害效能;生命表参数测定结果表明,室内饲养雌成虫的存活率可以达到63%,经过1个世代种群可以增长85.3638倍,在试验温度范围内种群周限增长率（λ）均大于1,后斑小瓢虫在实验室内饲养的种群成几何级数增长。通过生命表参数比较和功能反应模型分析,表明后斑小瓢虫对竹茎扁蚜具有较强的取食及繁殖能力,对竹茎扁蚜种群具有较强的控制能力。【结论】用竹茎扁蚜饲养的后斑小瓢虫种群成几何级数增长;后斑小瓢虫对竹茎扁蚜具有较大的控害潜能。

【Objective 】In order to understand the potential control capacity of Scymnus（Pullus） posticalis against Pseudoregma bambusicola, the optimum predator density, the maximum predatory amount, interference coefficient,instantaneous attack rate and treating time of S.（P.） posticalis fed on Pseudoregma bambusicola were studied. By measuring the life table of S.（P.） posticalis,I investigated the population growth trend of S.（P.） posticalis after feeding with P. bambusicola,to provide a scientific basis for utilizing S.（P.） posticalis to control P. bambusicola.【Method】Under laboratory conditions（temperature（23 ± 1） ℃,relative humidity（70%- 73%）,feeding with fixed time and fixed quantity in plastic cases was conducted to observe and measure the predation of S.（P.） posticalis on P.bambusicola,and to test S.（P.） posticalis ’s interference effect of its own density. With the application of Data Processing System,I used methods of insect ecology,such as the model of Holling-Ⅱ,the new model of Holling-Ⅲfunctional response developed by Wang Shize,and statistic model of functional response of predator to prey developed by Jin Kaizheng,for matching. Furthermore,I analyzed parameters of the optimum predator density,the maximum predatory amount,inference factor,instantaneous attack rate and treating time of P. bambusicola being preyed by S.（P.）posticalis,for studying the regulating effect of S.（P.） posticalis on P. bambusicola. I also used the rearing method of setting veil screen in the forest to measure the life table of experimented S.（P.） posticalis,in order to study S.（P.）posticalis’ s quantitative characteristic of inner increase capacity. 【Result】Under the controlled conditions,the predatory function responses showed that the average predation was able to amount 75 max per day for the 3rdinstar S.（P.）posticalis on P. bambusicola,and 81 max per day for adult S.（P.） posticalis,both the 3rdinstar and adult S.（P.）posticalis were strong predators of P. bambusicola. The interference effect test on S.（P.） posticalis’ s density showed that the pest control capacity of S.（P.） posticalis could reach the maximum when the release ratio was 1 ∶ 38. 8; and the parametric measure result of life table showed that the survival rate of indoor rearing female imagoes was able to reach63%,and after a generation,the population increased by 85. 3638 times. Meanwhile,within the test temperature range,when the reproductive rate（λ） was larger than 1,the population of lab reared S.（P.） posticalis increased in a geometric ratio. By comparing the parameters on life tables,and analyzing the models of functional response,it was shown that S.（P.） posticalis was a strong predator of P. bambusicola,and it had strong reproductive ability,and S.（P.） posticalis had strong pest control capacity against the population of P. bambusicola. 【Conclusion 】This study indicated that the population of S.（P.） posticalis fed with P. bambusicola grew exponentially,and it had a great potential of preventing and controlling P. bambusicola.