梨吉丁虫(Lampra limbata Gebl.)为梨、苹果、杏、樱桃、山楂的枝干害虫之一,我校梨树自1956午栽植以来连年受害,损失甚重。据了解此虫在南昌、永修、清江、上饶、贵谿、赣县、新干、崇仁等县亦有发生。在我校主要为害梨树,苹果上偶有发现。1961年以来我们对此虫进行了调查研究,所得结果报导于下。 为害情况及虫口密度 据历年调查,我校梨园1,350亩均受此虫为害,死树达5,000多株,占全部梨树22％,有二个果区(170亩)遭到毁灭。61年7月调查的结果如表1。 表1说明,无论虫株率及虫口密度都极严重。从树龄来看,三年生以下的梨树为害较轻,虫道分布在主干上较主枝上多;六午生树,主枝、主干大致相似,有些主枝上的虫数还超过了主干;无论三年生或六年生树, Lampra limbata Gebl. Is one of the pests of pears, apples, apricots, cherries and hawthorn. The pear tree of our school has suffered from successive years since it was planted in 1956, with heavy losses. It is understood that the pests in Nanchang, Yongxiu, Qingjiang, Shangrao, Guixi, Gan County, Xinjiang, Chongren counties have also occurred. Occur in my school mainly pear, apple occasionally found. We investigated this pest since 1961 and the results are reported below. Harm and Insect Density According to the survey over the years, 1,350 mu of pear orchard in our school were affected by this pest. There were over 5,000 dead trees, accounting for 22% of all pear trees. Two fruit trees (170 mu) were destroyed. The results of the survey in July 61 are shown in Table 1. Table 1 shows that no matter the worm rate and insect population density are very serious. From the tree age point of view, pears under three years of age less harmful insects, insects distributed in the trunk than the main branch more; six trees, the main branch, the trunk is generally similar to some of the main branch of the number of worms over the trunk ; Regardless of three-year or six-year-old trees,