武清县首次发现瑞典麦秆蝇为害春玉米自１９９７年５月中旬以来，在我县春玉米苗上发现一种新的虫害，植株被害后，症状表现为：整株植株变粗畸形；顶部叶片残缺；出现大量分蘖；有的心叶枯死、顶部叶片残缺散乱，或发生不同程度的皱缩，有的叶片上有不规则形纵裂孔或白色... Wuqing County found for the first time that Swedish corn flies damage spring maize Since mid-May 1997, a new pest was found on spring maize seedlings in our county. After the plants were killed, the symptoms were as follows: the whole plants became rough and deformity; the top Leaves incomplete; a large number of tillering; some heart leaves withered, the top blade fragmentation, or varying degrees of shrinkage, and some leaves irregularly shaped longitudinal holes or white ...