麻天牛是胶东麻区对大麻产量和品质威胁最大的一种害虫。过去曾用化学农药防治,但由于该虫活动范围大,寄主又不专一,收效不大。近年来根据该虫生活规律在农业栽培技术方面进行了一些改革,取得了较为显著的防治效果。一、对麻天牛生活习性的观察: 据1957年冬观察,麻天牛在越冬期间对低温有相当顽强的抵抗能力,在自然越冬的情况下,越冬幼虫可以忍耐-24℃的低温。该虫在胶东地区一年发生一代,越冬幼虫在五月下旬至六月上旬化蛹,六月中、下旬羽化,开始出现成虫。成虫需要补充营养,边食害麻株边产卵。七月上旬开始孵化成幼虫,在麻稈内食害髓和木质部,八月中、下旬幼虫移动到麻株根部准备越冬。二、防治办法: 1.提早播种:胶东群众为躲避春旱,适应大 Jatropha is the most harmful pest in the Jiao Dong area for its yield and quality. In the past, chemical pesticides were used for prevention and treatment. However, due to the wide range of activity of the insects and the lack of specificity of the hosts, the results were not very effective. In recent years, some changes have been made in the agricultural cultivation techniques according to the law of the pest’s life, and more significant prevention and control effects have been achieved. First, the observation of the living habits of hemp cattle: According to the winter of 1957 observed that during the wintering, hemp has a very tenacious resistance to low temperature, in the case of natural wintering, overwintering larvae can endure the -24 ℃ low temperature. The insects in the Jiaodong area a generation a year, overwintering larvae in late May to early June pupation, mid-June, late emergence, adult began to appear. Adults need to add nutrients, while infestation of hemp while spawning. In early July hatch into larvae, burying marrow and xylem in the stalk, in mid-August, late larvae move to the hemp roots ready for winter. Second, control methods: 1. Early sowing: Jiaodong people to avoid spring drought, adapted to large