不同熟期大豆豆杆黑潜蝇的危害特征分析

Analysis of Injurious Feature of Melanagromyza sojae on Soybean in Different Mature Period

调查结果表明,豆杆黑潜蝇在江苏沿海地区大豆田一年发生4代,不同熟期大豆的受害程度依次为秋大豆>夏大豆>春大豆;该虫的为害大体可分为过渡、扩散和重发3个阶段。豆杆黑潜蝇在大豆播后30～40d首先侵入大豆主茎,播后50～60d才钻入叶柄和分枝,豆株各部位受害程度表现为主茎>叶柄>分枝;从大豆不同播期的虫株率、虫孔数、单株虫道数以及虫道长度等来看,均表现为春大豆<夏大豆<秋大豆,即播种越迟,受害越重;对于同样的品种和播期而言,前茬为空白茬口豆田的受害程度要显著低于前茬有作物的豆田。

The investigative results show that Melanagromyza sojae reproduces four generations every year in soybean fields in the coastal area of Jiangsu province. The injured degree of soybean in different mature period is arranged as follows: autumn soybean>summer soybean>spring soybean, namely the later soybean is sowed, the more seriously it is injured. The injurious period of this pest insect consists of transition, spread and serious occurrence stages. M. sojae bores the main stem after 30～40 days following sowing, and injured the leaf stalk and branch on the 50th～60th day after sowing. The injured degree of the main stem is heavier than that of the leaf stalk, and the latter is heavier than that of the branch. As far as the same soybean variety sowed at the same time is concerned, the injured degree of soybean without previous crop is significantly lighter than that of soybean with previous crops.