茶毛虫低位侧向分布习性及其在防治中的应用

在茶毛虫(Euproctis pseudocospersa Strand)生态学研究中,观察到阶梯形茶园中的茶毛虫四龄前幼虫有规律地分布在茶丛两侧中下部叶片背面。在近20多天内,其垂直和水平活动范围相对稳定。以茶毛虫侧向分布规律为依据,设计了茶毛虫低位侧向快速喷药防治技术,改进了过去全丛喷雾为两侧中下部快速喷雾,并根据茶丛高度及幼虫龄期调节步速和喷幅,以提高防治效果。测定了5种杀虫剂不同剂量对茶毛虫及蜘蛛的影响和茶丛不同部位雾滴密度,建立了实施快速喷雾防治技术。可减少用药量约3/4;降低茶蓬面芽叶受药量;与常规方法防治效果相当,而工效提高约3倍。经3年小区试验和大面积推广示范,证明较经济有效,适于山区茶园应用。

UTILIZATION OF THE DISTRIBUTION HABITS OF THE CATERPILLAR EUPROCTIS PSEUDOCONSPERSA STRAND IN CHEMICAL CONTROL

Observations about the distribution habits of the tea caterpillar were conducted in Nangzheng County of Shaanxi Province. The results showed that the larvae before 4th instar distributed regularly on the under surface of the leaves in the middle and lower part of the bilateral tea rows, and the vertical and horizontal movements of the larvae keep relatively stable within the mentioned area within about 20 days. A quick sdraying technique of lateral canopy surface treatment was thus designed for the caterpillar control. The spray cloud was introduced directly onto the limited mentioned area, instead of. the conventional whole plant spray. Application rates and deposition densities of spray droplets of 5 insecticides used were determined and the control efficacies reported. Only one fourth of the conventional application dosage of pesticide was enough for control by the application techniques here described, and the pesticide-contamination of bud-tea could be decreased obviously.