4种农业措施对三化螟种群动态的控制作用

我国南方稻区是水稻三化螟主发生区。近年来，受农业机械化、产业结构调整、农田水利建设等影响，三化螟发生与为害呈现新的特点。本项研究分别在广东粤北、粤中和粤西，通过田间试验布局和调查，系统研究了隔离育秧、稻菜轮作、浸桩旋耕和烧桩4种农业措施对三化螟种群动态的控制作用。研究结果表明，隔离育秧、稻菜轮作和浸桩旋耕对于三化螟发生具有明显控制作用，而烧桩对三化螟控制效果不明显。隔离育秧与塑盘育秧、露地育秧这两种耕作方式相比，第2代本田白穗率、第4代白穗率、越冬虫口密度分别降低了43.4、53.7、14.0倍和14.4、11.0、4.7倍；稻菜轮作区与非稻菜轮作区比较，第2代本田白穗率、第4代白穗率和越冬虫口密度分别降低了24.4、43.3、152.3倍；浸桩旋耕与非浸桩旋耕区比较，第2代本田白穗率、第4代白穗率和越冬虫口密度分别降低了3.7、2.7、8.9倍；烧桩处理则仅比对照田三化螟存活率略低14.9%。轻简化和机械化将是未来水稻种植主流，本文对于指导生产实践中三化螟防治具有重要意义。

Effects of four different agricultural prevention and control measures on rice yellow stem borer Tryporyza incertulas (Walker)(Lepidoptera: Pyralidae )

Southern China is the main occurrence area of rice yellow stem borer (YSB, Tryporyza incertulas (Walker)). In this area, new features of the outbreak and damage of YSB has occurred that caused by many factors such as agricultural mechanization, industrial restructuring and construction of water conservancy, etc. in recent years. Four agricultural measures had been accomplished for controlling the population of YSB in three localities of Guangdong province such as Fogang (northern), Gaoyao (central) and Leizhou (western), during Feb. 2008 to Feb. 2010. Just as isolated planting (which required some equipments for rice nursery plant in greenhouses, it was different with film cover nursery and outdoor nursery), rice-vegetable crops rotation (a pattern of planting vegetables for one year after planting rice for one year, and accomplished the rotation between vegetables planting and rice planting), rice stubble soaked with water and rotary tiller technique (rice field was irrigated in spring, and the rice stubble were soaked in which YSB individuals left would be killed. The soil of rice field will be rotary tilled by using rotary tillers), and burning rice stubble (burn the rice stubbles to kill the residual pests and improving the soil fertility of rice fields). The results indicated that the agricultural measures such as isolated planting, rice-vegetable crop rotation, rice stubbles soaked with water and rotary tilling, had significant effects on controlling the population of YSB, while there was no significant effect on controlling the population of YSB by using the measure of burning rice stubble. The whitehead rate of 2nd and 4th generations, and population density of over winter YSB in the rice fields by measure of isolated planting had declined 43.4, 53.7, 14.0 times and 14.4, 11.0, 4.7 times, respectively, compared to those by measure of scattered planting and natural planting. The 2nd and 4th generations whitehead rate, and population density of over winter YSB in the rice fields by using the measure rice-vegetable crop rotation had respectively declined 24.4, 43.3, 152.3 times compared with that of non rice-vegetable crop rotation zones. The 2nd and 4th generations whitehead rate, and the population density of over winter in the rice fields by used rice stubbles soaked with water and rotary tiller technique had respectively declined 3.7, 2.7, 8.9 times compared with non rice stubbles soaked with water and rotary tiller technique zones, However, the survival rate of YSB in rice fields by using the measure of burning rice stubble was only 15% lower than that of control experiment. Light and simple cultivation technique and mechanization of rice planting would become more and more popular in the near future. To explore new agricultural measures would be meaningful for the management strategies of YSB.