随着玉米品种全面杂交化,晚熟玉米几乎绝播,二、三代玉米螟趋向于棉田危害。产业结构调整以后,棉田面积大量缩减,往往导致它集中危害。1984年以前,我区植棉面积为5.5万亩,现在仅植2万亩,减少了63.6%,近二年来棉田受害加剧。其二代主要危害棉株茎叶和部分早蕾,三代除危害蕾外,主要蛀食青铃,造成大量烂铃,棉花的品质、产量均下降。据近几年调查,蛀铃率为1.21～21.2%,严重田块高达64%,危害程度接近或超过红铃虫。如何防治好棉田三代玉米螟,已成为本地迫切需要解决的课题。三代的发生期(我地一般是在8月份)正与棉株开花结铃高峰期吻合,其时棉株高大,田间阴蔽度加剧,有利于其产卵危害,加上世代不整齐,发生期拉长,产卵峰次多,药剂防治一般都难以奏效,为了能有效控 With the full hybridization of corn varieties, late maturing corn almost completely sowing, the second and third generations of corn borers tend to damage the cotton field. After the adjustment of the industrial structure, a substantial reduction in the area of ​​cotton fields often leads to its concentration on the hazards. Before 1984, the area of ​​cotton in our district was 55,000 mu, and now it has only planted 20,000 mu, a decrease of 63.6%. The cotton fields have been harmed in the past two years. The second generation of the main harm cotton plant stems and leaves and some of the early buds, three generations in addition to harmful buds, the main eaten green bell, causing a large number of rotten bell, cotton quality, yield declined. According to the survey in recent years, the rate of boll boll was 1.21 ~ 21.2%, and the number of serious plots was as high as 64%. The damage degree approached or exceeded that of red bollworm. How to prevent and control the three generations of cotton field cotton borers, has become an urgent issue to be solved. The occurrence of the third generation (I usually in August) and the cotton boll flowering peak period coincide, when the cotton plant tall, field shade degree is conducive to their spawning hazards, together with the generation of irregularities occur Extensions, spawning times, drug control generally difficult to work, in order to effectively control