Studies on the community characteristics of major arthropods in summer maize fields

This study is to integrate pest management （IPM） of maize insect pest. The paper reports the current condition of species diversity of maize field in Nanning, Guangxi Province. All exper/mcntal materials were collected dur/ng the stages of tasseling, blister, milk, maturity and after reaping respectively from 5 plots from April to July, 2007. The Shannon-Wiener index（H）, Simpson index（H＇）, Brillouin index（J）, species evenness（E） and richness index （Dmc） were used into analysis of abundance and distribution characteristics of communities and populations of major arthropods in maize fields. Result showed that a total of 19 arthropods, belonged to 10 orders and 18 families, were obtained from maize fields. Of which there are 12 pest insects, 3 natural enemy insects, 2 spiders and 2 middle insects. All of the community diversity indices were the highest in maize fields after reaping. No significant difference was found between other 4 various stages i.t. tasseling, blister, milk and maturity stages. The results of this study will help to carry out the IPM of maize field pest insect.

农田昆虫类群组成与玉米大斑病发生联系研究

【目的】探讨农田内玉米大斑病Exserohilum turcicum发生与昆虫类群组成之间联系,昆虫体壁对玉米大斑病病原物携带情况。【方法】结合病虫害野外调查、病原物室内培养分离、生理生化及分子生物学鉴定方法确定昆虫体壁携带玉米大班病病原物。【结果】通过对农田内玉米大斑病发生时期的昆虫类群组成调查,发现农田内的昆虫群落物由9目,45科,60种昆虫昆虫所组成,包括双翅目、鞘翅目、鳞翅目、半翅目、膜翅目、蜉蝣目、脉翅目、直翅目及革翅目。其中,双翅目为优势类群,其次为鞘翅目和鳞翅目。通过室内对虫体壁病原物进行镜检、分离纯化及病原物DNA序列测定比对,发现农田内昆虫体壁携带玉米大斑病病原物。鞘翅目2种昆虫独角蚁形甲Notoxus monoceros和双斑萤叶甲Monolepta hieroglyphica携菌率显著高于双翅目昆虫(P<0.05),但携菌昆虫种类少于双翅目。玉米大斑病爆发期农田内昆虫数量与玉米大斑病发病等级相关性分析结果表明,昆虫种类随着玉米大斑病病情的加重而呈现正相关关系。【结论】农田内昆虫类群组成与玉米大斑病病原物存在一定关联,昆虫体壁携带玉米大斑病病原物对玉米大斑病传播作用不明显。