为了节省劳力和经济用药,一般确定防治螟虫的原则:在上一代螟虫集中为害而下一代分散的情况下,就狠治上一代,争取不治或少治下一代;在上一代造成枯心苗而下一代造成白穗的情况下,就狠治上一代的枯心苗,争取少治或不治下一代的白穗。 江苏省三化螟虫每年发生三代。水稻品种布局大致可分为以中稻为主的早、中、晚稻混栽地区,和以晚稻为主的中、晚稻并存地区。三化螟在这种情况下,全年的为害规律是:第一代高度集中,第二代高度分散,第三代又相对集中。第一代主要集中在部分早播秧田和最早栽插的大田中为害。一般 In order to save labor and economic medicine, the principle of stem borer control is generally established: in the case of the next generation of dispersal of the previous generation of stem borers, the previous generation should be ruthlessly managed to fight for the next generation or to the next generation; The next generation caused the case of white spike, the cruel rule of the previous generation of withered seedlings, fight less rule or rule the next generation of white spike. Three generations of stem borers in Jiangsu Province occur three generations each year. Rice varieties can be broadly divided into medium-sized rice-based early, middle and late rice mixed planting areas, and late rice-based co-existence of late rice. Borer in this case, the annual pattern of damage are: the first generation of highly concentrated, the second generation of highly dispersed, the third generation is relatively concentrated. The first generation was mainly concentrated in some early-sowing seedlings and planting the earliest in the field damage. general