<正>运用复合经营、保护与释放天敌等综合措施对杨树天牛进行了生态控制研究。结果表明：杨树复合经营、保护天敌与释放肿腿蜂的模式对杨树天牛的抑制效果最佳，其有虫株率、平均虫口密度和相对虫口密度较对照组分别下降66.0%、98.3%和4J.5%：释放肿腿蜂并与白僵菌结合的防治效果也明显提高。此外，肿腿蜂释放后可在杨树林间形成野外种群，并对杨树天牛具有很好的持续控制作用。据此，推荐在杨树种植区大面积实施复合经营，辅以释放肿腿蜂，以达到生态控制天牛的目的。

The common methods of extracting information of forest using ETM+remote sensing image were discussed in this paper. According to the analysis of eigenvalue and relativity, it was found that bands of TM3, TM4 and TM5 had small relativity and contain ample information. Bands of TM3, TM4 and TM5 were merged with PAN bands using Brovey transform. NDVIR was obtained by computing Normalized Difference Vegetation Index for bands of TM4R and TM3R of merged remote sensing image. Then the combination image of fusion remote sensing images and NDVIR image was classified by method of maximum likelihood. The forest cover rate was computed to be 38.63% according to the classification.