淮北棉田害虫与捕食性天敌群落动态变化研究

对淮北棉田害虫和捕食性天敌群落动态变化进行了研究。田间系统调查共发现害虫35种,捕食性天敌24种;害虫优势种为棉蚜、烟粉虱、棉叶螨、棉盲蝽;捕食性天敌优势种主要为四点亮腹蛛、龟纹瓢虫、T-纹豹蛛、草间小黑蛛、八斑球腹蛛、华姬猎蝽、小花蝽、青翅隐翅虫。该区棉田害虫与捕食性天敌在棉株上的分布特点为:四点亮腹蛛、T-纹豹蛛、草间小黑蛛、八斑球腹蛛、小花蝽、青翅隐翅虫为下部>中部>上部;烟粉虱、棉盲蝽为上部>中部>下部;华姬猎蝽7月30日前为上部>下部>中部,8月9日后为下部>上部>中部;棉蚜在6月20日前为上部>下部>中部,在6月30日后为下部>上部>中部;棉叶螨前期主要分布在下部,后期向上转移;龟纹瓢虫在7月10日前为上部>中部>下部,7月20日之后为下部>上部>中部。群落均匀度在棉花生长发育前期较低,中期逐渐上升,后期又逐渐下降;集中度的变化趋势与均匀度相反;多样性在棉花生育中期最高。以物种为单位和以功能团为单位的群落多样性指数和均匀度指数呈高度正相关,相关系数(r)为0.9904。

Dynamics of insect pests and predatory enemy communities in cotton fields in north of the Huaihe River, Anhui Province

The dynamics of insect pest and predatory enemy communities in cotton fields in north of Huaihe River,Anhui Province was studied.35 species of insect pests and 24 species of predatory enemies were found.The dominant species of insect pests are Aphis gossypii,Bemisia tabaci,Tetranychus cinnabarinus,and Adelphocoris spp.,and the dominant species of predatory enemies are Singa pygmaea,Propylaea japonica,Pardosa T-insignita,Erigonidium graminicolum,Theridion octomaculatum,Nabis sinoferus,Orius similis and Paederus fuscipes.Among the dominant species,the distribution ratio of S.pygmaea,P.T-insignita,E.graminicolum,T.octomaculatum,O.similis and P.fuscipes on the cotton plants is:lower part >middle part>upper part;for B.tabaci and Adelphocoris spp.,it is:upper part>middle part>lower part;for N.sinoferus,it is:upper part>lower part>middle part before July 30,and lower part>upper part>middle part after Aug.9;for A.gossypii, it is:upper part>lower part>middle part before June 20,but lower part>upper part>middle part after June 30;for P.japonica,it is:upper part>middle part>lower part before July 10,but lower part>upper part>middle part after July 20.T.cinnabarinus mainly exists in the lower part of the cotton plant in the prophase and then moves up.The evenness of the communities is relatively low during the early development stage of the cotton plant,but rises gradually during the middle development stage and declines eventually during late development stage.The change trend of the enemy community concentration is inversely related to its evenness.During the middle development stage of cotton,the community is most diverse.Species community diversity and evenness index has significant relationship with the guild community diversity,the correlation coefficient is 0.9904.