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

Abstract

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.