<正>用２．５、５．０、１０．０、２０．０、５０．０、１００．０ｍｇ／ｋｇ灭幼脲水溶液处理的野蔷薇枝条连续饲喂云斑天牛成虫，测定了成虫取食量消长和子代卵孵化率消长。根据成虫取食量与子代卵孵化率的关系，统计不同期距条件下成虫取食量消长与子代卵孵化率消长的符合率。期距５、１０、１５、２０、２５天时，符合率分别为３６．２３％、５７．９７％、４１．７９％、６５．５７％、３２．８３％。结果表明：灭幼脲对云斑天牛不育作用的效应期为１０～２０天。初步认为：灭幼脲对成虫的不育效应系成虫体内灭幼脲入卵所致，灭幼脲入卵时期为卵黄发生期。灭幼脲作为成虫不育剂使用时适用于卵子发生在成虫期进行的昆虫，施药时间应在卵黄发生之前。

Adult Batocera horsfieldi （Hope） were fed continuously with rose branches treated with diflubenzuron （DFB） at a concentration of 2．5、5．0、10．0、20．0、50．0、100．0mg／kg． The relationship between dynamic state of adults foodintake and that of progenyeggs hatchability was evaluated in the laboratory． When the concentration of DFB aqueous solution varied from 2．5mg／kg to 100．0mg／kg， the adults foodintake was inversely proportional to progenyeggs hatchability． On the basis of relationship mentioned above, we calculated the rate of the concordance between the dynamic state of adults foodintake and that of progenyeggs hatchability under conditions of different intervals． When the interval was 5、10、15、20d and 25d， the rate of concordance was 36．23％、57．97％、41．79％、65．57％、32．83％，respectively． It was concluded that the effective phase of chemosterilization by DFB in B． horsfieldi was about 10～20d． The results also showed that ingestion of DFB by progenyeggs was the main cause of sterile activities of DFB on the adult． The critical period when DFB in the hemolymph got into progenyeggs was the vitellogenesis stage． Insects whose oogenesis appeared in adult stage were apt to be sterilized by DFB． The optimal treating season was before the vitellogenesis stage．