根據各地三(san)化(hua)(hua)螟冬(dong)后蟲源基數調查，結合全(quan)區今春農(nong)情及氣候特(te)點，參考歷史(shi)資料綜合分(fen)析(xi)，預計第(di)一(yi)代(dai)三(san)化(hua)(hua)螟發(fa)(fa)生程度為偏(pian)輕、局(ju)部(bu)中(zhong)(zhong)(zhong)(zhong)等，輕于上(shang)年(nian)與常年(nian)。發(fa)(fa)生面(mian)積約100萬(wan)畝(mu)。發(fa)(fa)生主(zhu)要(yao)區域是桂中(zhong)(zhong)(zhong)(zhong)、右江(jiang)河谷及桂西(xi)(xi)北(bei)的(de)局(ju)部(bu)，其(qi)中(zhong)(zhong)(zhong)(zhong)武宣(xuan)、柳江(jiang)、環江(jiang)、巴馬、大化(hua)(hua)、凌云(yun)、田林等縣局(ju)部(bu)稻區將偏(pian)重發(fa)(fa)生。桂東南稻區第(di)一(yi)代(dai)成(cheng)蟲盛發(fa)(fa)期(qi)(qi)在(zai)3月(yue)中(zhong)(zhong)(zhong)(zhong)旬(xun)(xun)(xun)至(zhi)4月(yue)中(zhong)(zhong)(zhong)(zhong)旬(xun)(xun)(xun)，比去(qu)(qu)年(nian)偏(pian)遲6天左(zuo)右；右江(jiang)河谷、桂西(xi)(xi)北(bei)稻區第(di)一(yi)代(dai)成(cheng)蟲盛發(fa)(fa)期(qi)(qi)在(zai)3月(yue)下旬(xun)(xun)(xun)至(zhi)4月(yue)下旬(xun)(xun)(xun)初，比去(qu)(qu)年(nian)偏(pian)遲3~6天；其(qi)它稻區4月(yue)上(shang)旬(xun)(xun)(xun)至(zhi)5月(yue)上(shang)旬(xun)(xun)(xun)，比去(qu)(qu)年(nian)稍遲。螟蛾主(zhu)要(yao)集中(zhong)(zhong)(zhong)(zhong)在(zai)秧(yang)田及早移(yi)植田發(fa)(fa)生、為害。
主要依據
1 有效蟲源面積 統計49個(ge)縣（市、區）2010年第四代三化螟發生面積152.47萬畝，分別比上年同期、歷年平均減少27.51%、50.12%；加權平均殘(can)蟲量為(wei)437.89頭/畝，分別比上年同期、歷年平均減少18.94%、43.88%。
2 冬(dong)后蟲源基(ji)數 統計40個縣（市(shi)(shi)、區(qu)）加權平(ping)(ping)均(jun)冬(dong)后密度為311.56頭/畝，分別比上年(nian)同期(qi)、歷年(nian)平(ping)(ping)均(jun)減少(shao)50.44%、70.60%。其中來(lai)賓、柳州兩市(shi)(shi)9個縣（市(shi)(shi)、區(qu)）加權平(ping)(ping)均(jun)冬(dong)后密度為666.72頭/畝，分別比上年(nian)同期(qi)、歷年(nian)平(ping)(ping)均(jun)減少(shao)41.54%、74.13%。
3 氣(qi)候(hou)因子 2011年(nian)(nian)(nian)1月(yue)(yue)(yue)全區(qu)平(ping)(ping)(ping)均氣(qi)溫(wen)(wen)6.9℃，比(bi)常(chang)年(nian)(nian)(nian)同(tong)(tong)(tong)(tong)期(qi)偏(pian)(pian)(pian)低(di)4.3℃，為(wei)1951年(nian)(nian)(nian)以來同(tong)(tong)(tong)(tong)期(qi)第2低(di)；平(ping)(ping)(ping)均降(jiang)雨(yu)量(liang)(liang)20.6mm，比(bi)常(chang)年(nian)(nian)(nian)同(tong)(tong)(tong)(tong)期(qi)偏(pian)(pian)(pian)少(shao)(shao)(shao)5.5成(cheng)(cheng)。2月(yue)(yue)(yue)全區(qu)平(ping)(ping)(ping)均氣(qi)溫(wen)(wen)13.7℃，比(bi)常(chang)年(nian)(nian)(nian)同(tong)(tong)(tong)(tong)期(qi)偏(pian)(pian)(pian)高1.2℃；平(ping)(ping)(ping)均降(jiang)雨(yu)量(liang)(liang)35.1mm，比(bi)常(chang)年(nian)(nian)(nian)同(tong)(tong)(tong)(tong)期(qi)偏(pian)(pian)(pian)少(shao)(shao)(shao)3.9成(cheng)(cheng)。統計42個縣（市、區(qu)）各類型(xing)田加(jia)權(quan)平(ping)(ping)(ping)均死(si)亡率為(wei)11.86%，分別比(bi)上(shang)(shang)年(nian)(nian)(nian)同(tong)(tong)(tong)(tong)期(qi)、歷年(nian)(nian)(nian)平(ping)(ping)(ping)均增36.16%、5.70%。3月(yue)(yue)(yue)上(shang)(shang)旬全區(qu)各地旬平(ping)(ping)(ping)均氣(qi)溫(wen)(wen)偏(pian)(pian)(pian)低(di)，日照時數偏(pian)(pian)(pian)少(shao)(shao)(shao)，降(jiang)雨(yu)量(liang)(liang)除了西部(bu)偏(pian)(pian)(pian)少(shao)(shao)(shao)外(wai)其(qi)它地區(qu)偏(pian)(pian)(pian)多(duo)。據氣(qi)象臺預報，3月(yue)(yue)(yue)下旬至4月(yue)(yue)(yue)上(shang)(shang)旬，全區(qu)大部(bu)地區(qu)氣(qi)溫(wen)(wen)比(bi)常(chang)年(nian)(nian)(nian)同(tong)(tong)(tong)(tong)期(qi)偏(pian)(pian)(pian)高0.1~1℃，與常(chang)年(nian)(nian)(nian)同(tong)(tong)(tong)(tong)期(qi)相比(bi)，降(jiang)雨(yu)量(liang)(liang)桂南大部(bu)偏(pian)(pian)(pian)少(shao)(shao)(shao)1~2成(cheng)(cheng)，桂北大部(bu)偏(pian)(pian)(pian)多(duo)1~2成(cheng)(cheng)。低(di)溫(wen)(wen)陰(yin)雨(yu)天氣(qi)會導致越(yue)冬三(san)化(hua)螟化(hua)蛹和羽化(hua)的延遲，發生(sheng)量(liang)(liang)會相對減少(shao)(shao)(shao)。
4 農事活動(dong) 截止3月10日(ri)，全(quan)區(qu)已浸播(bo)早稻(dao)種子1025.62萬(wan)公斤，占應播(bo)量的40.98%，同(tong)(tong)比(bi)(bi)(bi)分別多61.79萬(wan)公斤、2.32個百分點，其(qi)中梧州(zhou)(zhou)、北海、玉林市早稻(dao)種子浸播(bo)已逾(yu)八成。全(quan)區(qu)已犁耙田433.50萬(wan)畝，整秧田58.97萬(wan)畝。全(quan)區(qu)早稻(dao)插(cha)秧進度較去(qu)年同(tong)(tong)期(qi)(qi)稍慢，北海、貴港(gang)、玉林和(he)崇左市開始插(cha)秧，已插(cha)早稻(dao)0.28萬(wan)畝，同(tong)(tong)比(bi)(bi)(bi)少(shao)0.29萬(wan)畝。除梧州(zhou)(zhou)、北海、防城港(gang)等市水(shui)庫(ku)(ku)蓄水(shui)量比(bi)(bi)(bi)去(qu)年同(tong)(tong)期(qi)(qi)減少(shao)外(wai)，其(qi)它11個市的水(shui)庫(ku)(ku)蓄水(shui)量均比(bi)(bi)(bi)去(qu)年同(tong)(tong)期(qi)(qi)有所(suo)增加。其(qi)中崇左、百色(se)、河(he)池、來賓、柳州(zhou)(zhou)市分別比(bi)(bi)(bi)去(qu)年同(tong)(tong)期(qi)(qi)增0.84、0.70、0.49、0.22、0.13億(yi)立(li)方(fang)米。3月上旬統計：全(quan)區(qu)水(shui)庫(ku)(ku)有效(xiao)蓄水(shui)量為35.04億(yi)立(li)方(fang)米，占有效(xiao)庫(ku)(ku)容的35.30%，比(bi)(bi)(bi)上年同(tong)(tong)期(qi)(qi)增3.47億(yi)立(li)方(fang)米，比(bi)(bi)(bi)歷(li)年平均減少(shao)7.38億(yi)立(li)方(fang)米。
防治意見
3月(yue)下旬初至4月(yue)中旬初為防(fang)治第(di)一代三化螟(ming)的關鍵(jian)時段，各級植保技(ji)術(shu)人員要堅持(chi)田間(jian)調查(cha)，針對當地(di)蟲情，因地(di)制(zhi)宜制(zhi)定防(fang)治策略，開展分類指導。
1 農(nong)業(ye)防治 指導農(nong)民群眾抓緊時(shi)機(ji)在三化(hua)(hua)螟(ming)成蟲羽化(hua)(hua)前開展耙漚滅(mie)螟(ming)，盡可能(neng)利(li)用(yong)機(ji)耕以加速禾(he)蔸的腐爛(lan)，提高滅(mie)螟(ming)效果。
2 人工摘除卵(luan)塊 指導農民人工摘除秧田的三(san)化螟(ming)卵(luan)塊，降低(di)第一代三(san)化螟(ming)蟲源基數。
3 燈光誘(you)殺(sha) 成蟲(chong)發生期(qi)間，用頻振式殺(sha)蟲(chong)燈誘(you)殺(sha)成蟲(chong)。
4 化學防治 對于達防治指標的田塊，應掌握在卵孵高峰期進行，選用安全、高效、經濟、對口農藥。
