油菜蚤跳甲的为害分级及习性

在甘肃临夏县调查发现，春季油菜蚤跳甲的越冬成虫可潜藏在杨树的老翘皮下、地边土缝及田间表土中蛰伏。田间为害春油菜幼苗的成虫量随当时的气温而变化。田间成虫数量的调查结果往往不能代表实际的危害状况。通过对被害苗的详细调查归类，本文提出了油菜蚤跳甲为害的分级标准，建议以被害指数来表示该虫的危害程度，以便在综合防治中能准确的表示虫情。

Damage Grades and Habits of Psylliodes punctifrons Baly

：Psylliodes punctifrons Baly is one of main pests attacking spring-sown rape in the west of China. In the early spring, over wintered adults usually hide under the warped bark of poplar near the field, in the crack of a low bank of earth between fields and in the surface soil of the spring-sown rape field, while the air temperature is low. So ,the number of adults emerging in the field is affected by the air temperature. The damage to spring-sown rape should be expressed with damage index to the plant of the crop according to damage degree proposed by author in this paper.