【摘要】 梨笠圆盾蚧Ｑｕａｄｒａｓｐｉｄｉｏｔｕｓｐｅｒｎｉｃｉｏｓｕｓ（Ｃｏｍｓｔｏｃｋ）是枣林的重要微小害虫，在山西一年发生２代，以第２代的２龄若虫于１—３年生的枝条上越冬，次年３月下旬开始活动，雌雄若虫均为两龄，第２代和第１代成虫分别于５月上旬和７月中旬开始羽化，５月下旬和８月上旬分别产出第１代和第２代若虫。雌雄性比分别为１：０．２６和１：０．３５。本文也研究了寄主不同部位、不同方位与各代虫口密度、自然死亡率的变化规律；若虫在叶面的分布规律；寄主枝龄与寄生密度对种群的影响；各虫态发生的起迄日期；发育进度与温湿度的关系；发育所需天数。为测报成虫羽化盛期和产仔盛期提供了理论依据更多还原

【Abstract】 The scale insect Quadraspidiotus perniciosus (comstock) is one of the important pests of jujube.In Shanxi Province,this insect has two generations a year and overwinters as 2nd instar nymph of the 2nd generation on the branch.The overwintering nymphs begin to harm the host in late March the following year.The nymphs of male and female have two instars.The adults of the second and the first generations emerge in early May and in mid-July,respectively.The sex ratios of the two generations are 1:0.26 and 1:0.35,respectively.The ralationship between the population density and natural death rate and the different parts and directions of the host plant are also investigated.Besides,the distribution of the nymphs on the jujube leaf,the effect of the branch age and the density of the pest on the fluctuation of the population,the forecasting to the occurance of the nymphs and adults,and the temperature and moisture on the development of the pest,and the methods of control are also studied.更多还原