楸树为云台山区速生、优质用材树种,被称为“北方的杉木”,深受群众喜爱,是云台山区今后发展的树种之一。惟近年来遭受楸螟为害很严重,据调查我场苗圃移植苗被害率达6.6％。朝阳林区幼林和成林被害率达72％,萌芽更新林和苗木受害更重。被害的楸树造成枯梢,枝条丛生,树势衰弱。为了寻求有效的防治方法,我们对这一害虫曾进行了观察和防治试验,现将初步的结果报告如下:一、生活习性每年发生二代,11月上旬以老熟幼虫(体长1.4—1.7厘米)在被害枝条中越冬。春暖后开始在枝条髓部危害,粪屑留存在虫道的上下部,虫道长6—12厘米。4月下旬开始化蛹前,先在虫道上端咬一个圆形羽化孔,并吐丝封闭,羽化时成虫破丝被飞出,飞翔能力可达 Catalpa tree is fast-growing, high-quality timber species in Yuntai Mountain, known as the “northern fir”, loved by the masses, is one of the tree species for the future development of Yuntai Mountain. However, in recent years, the catastrophic damage of M. sorbifolia was very serious. According to the survey, the damage rate of transplanting seedlings in our field reached 6.6%. Chaoyang forest young forest and forest damage rate of 72%, sprout regeneration forest and seedlings harmed. Catastrophe caused by the murky tree shoots, branches clusters, weak trees. In order to seek an effective control method, we have carried out observation and prevention and control tests on this pest. The preliminary results are reported as follows: First, the second generation occurs in the habits and habitats, and the mature larvae (body length 1.4-1.7 Cm) Wintering branches in the victim. After the spring began to damage the branches of the pulp, feces left in the upper and lower parts of the worm, worm length 6-12 cm. Before the start of pupation in late April, a circular feathering hole is bite at the upper end of the larvae, and the silk is closed. When the feathering occurs, the adult silkworm is ejected and the flying ability is up