论文部分内容阅读
为探求害虫防治时期,和发生数量方面的防治标准,以三化螟(Tryporyza incertulas (Wlk.)、二化螟(Chilo suppressalis Wlk.)和稻瘿蚊(Pachydiplosis oryzae Wood-mason)三种水稻钻心害虫为材料,探討钻心类害虫防治标准的規律,提出如下意見: 1.关于防治时期的标准,認为可将施药时虫态的发育进度百分率数字,换算为概率单位,在概率单位为4—6时,相当于15.87—84.13％时的害虫相对发生数量,占全世代总发生数量的68.268％,可見在該段短时間(一般約十数天)的虫数,代表了虫羣的大半数,可看作标准的盛发期,在此时間数列范围內,似可作为防治时期的标准。 2.关于发生数量的防治标准,以三化螟及稻瘿蚊为例进行討論:認为应以幼虫侵入作物后至老熟(或蛹化)期間,每虫所能造成的被害株数为基础,求出幼虫密度的防治标准,然后根据調查时的不同虫态,再伸算各該虫态的防治标准。本文列举了各虫态密度防治标准的計算公式,并以广州及南京两地的三化螟和广东信宜的稻瘿蚊为例,作出在各种具体条件下,虫口密度防治标准检索表。
In order to explore the pest control period and the number of occurrence and prevention standards, three kinds of rice, including Tryporyza incertulas (Wlk.), Chilo suppressalis Wlk. And Pachydiplosis oryzae Wood-mason Pests as materials to explore the law of the type of drilling center pests and put forward the following opinions: 1. Regarding the standard of prevention and control period, it is considered that the percentage of developmental progress percentage of the state of insects at the time of application can be converted into the unit of probability and the unit of probability is 4 -6, equivalent to 15.87-84.13% of pests when the relative number of occurrence, accounting for 68.268% of the total number of generations, we can see in this short period of time (usually about ten days) number of insects, representing the swarm Most of them can be regarded as the standard Shengfa period, within the time series, it may be used as the standard of prevention and control period. (2) On the occurrence of the number of prevention and control standards to the rice stem borer and rice gall midge mosquito as an example for discussion: It is suggested that the larvae density should be determined based on the number of harms that each larvae can cause after larvae invade the plants to mature (or pupal), and then according to the different insect states at the time of investigation, The worm control standards. This article lists Control standard density instars formula, and the yellow stem borer to both Nanjing and Guangzhou Xinyi and the gall midge, for example, be made in a variety of specific conditions, population density control standards retrieval table.