桂花上桔全爪螨种群消长规律及与环境因子的关系

本文研究了结全爪螨种群在桂花上的消长规律及与环境因子的关系。桂花桔全爪螨种群一年中有４个高峰，其为害最高峰在４月中旬～５月上旬及５月中旬～６月上旬，环境因子温度、相对湿度、光照时数、降雨量及天敌对卵量影响较小，对幼、葳、成螨的数量影响较大，其中天因子的影响尤为显著，螨量与光照时数呈负相关的关系。螨量与环境因子的逐步回归方程：ｙ５＝０．２５６２＋０．０５８４ｘｒ２－０．１３２ｘｓ１＋０．１１７２ｘ３

THE LAW OF GROWTH AND DECLINE OF THE POPULATION OF CITRUS RED MITE PANONYCHUS CITRI MCG.IN FIELD AND THE RELATIONSHIP OF THE POPULATION DENSITIES WITH ENVIRONMENTAL FACTORS

The paper studies the law of growth and decline of the population densities of citrus red mite Panonychus citri McG. on Osmanthus fragrans and its relationship with environmental factors. There are four peak periods of population densities in one year, of which two peaks(mid April to early of May and mid-May to early of June) are the highest. The effect of environmental factors, namely temperature, relative humidity, light hours, rainfall and predatory enemies(Phytoseius and Anysitis),is not obvious to egg densities; but it is obvious to densities of larva, nymph and adult.The influence of predatory enemies is the greatestofall.The mite densities are in inverse proportion to light hours. The regression formulas about the densities(No./leaf)of the red mite(Y5), except for eggs, are buit as follows: Y5=0. 2562+0. 0.584xT2(temperature of the previous day of investigation)-0. 1320xs1(light hours of the same day)+ 0. 1172x31(numbers of major natural predator mites)(R=0.5761)