根據全省(sheng)(sheng)冬后基數調查，結(jie)合歷(li)史(shi)資料(liao)、全省(sheng)(sheng)水稻(dao)生產(chan)區域特點及未來天(tian)氣(qi)趨勢綜(zong)合分析，今(jin)年(nian)一(yi)代二化螟預(yu)計在(zai)全省(sheng)(sheng)大部稻(dao)區大發生，如(ru)防治不力，早稻(dao)枯(ku)鞘率(lv)可能達到20%，中稻(dao)枯(ku)鞘率(lv)可能達到30%以上，造成缺苗。具體預(yu)報如(ru)下(xia)：
一、發生程度
預計一代二(er)化(hua)螟在(zai)鄂東、江漢平(ping)原大發(fa)生（5級），主(zhu)要危害早(zao)(zao)稻(dao)和中(zhong)稻(dao)秧(yang)田(tian)。早(zao)(zao)稻(dao)大田(tian)平(ping)均畝卵量在(zai)500塊以(yi)上，中(zhong)稻(dao)秧(yang)田(tian)平(ping)均畝卵量將達750塊以(yi)上。鄂北、鄂西北稻(dao)區、鄂西南(nan)稻(dao)區中(zhong)等偏(pian)重發(fa)生（4級），主(zhu)要為害中(zhong)稻(dao)。
二、發生期
預(yu)計江漢(han)平(ping)原(yuan)(yuan)中南(nan)部、鄂東(dong)南(nan)、鄂東(dong)沿江稻區成(cheng)(cheng)蟲羽化(hua)盛期(qi)(qi)(qi)４月(yue)(yue)(yue)18日(ri)(ri)(ri)~5月(yue)(yue)(yue)9日(ri)(ri)(ri)，卵孵(fu)盛期(qi)(qi)(qi)4月(yue)(yue)(yue)30日(ri)(ri)(ri)~5月(yue)(yue)(yue)19日(ri)(ri)(ri)， 發生(sheng)期(qi)(qi)(qi)比(bi)去(qu)(qu)年早2~3天(tian)，與常年持平(ping)。鄂北、鄂西(xi)稻區成(cheng)(cheng)蟲羽化(hua)盛期(qi)(qi)(qi)5月(yue)(yue)(yue)9日(ri)(ri)(ri)~5月(yue)(yue)(yue)24日(ri)(ri)(ri)，卵孵(fu)盛期(qi)(qi)(qi)5月(yue)(yue)(yue)19日(ri)(ri)(ri)~6月(yue)(yue)(yue)5日(ri)(ri)(ri)，發生(sheng)期(qi)(qi)(qi)與去(qu)(qu)年持平(ping)。江漢(han)平(ping)原(yuan)(yuan)、鄂東(dong)一代二化(hua)螟將會出現兩個(ge)明(ming)顯的孵(fu)化(hua)峰，5月(yue)(yue)(yue)3日(ri)(ri)(ri)~5月(yue)(yue)(yue)6日(ri)(ri)(ri)，5月(yue)(yue)(yue)12日(ri)(ri)(ri)~5月(yue)(yue)(yue)15日(ri)(ri)(ri)。
三、主要依據
（一）冬(dong)后(hou)殘(can)蟲(chong)基(ji)數(shu)高(gao)。據4月殘(can)蟲(chong)量剝查(cha)：江漢平(ping)(ping)原冬(dong)后(hou)每(mei)畝(mu)活(huo)蟲(chong)基(ji)數(shu)180-17656頭(tou)，加(jia)權(quan)平(ping)(ping)均4992.76頭(tou)，比(bi)(bi)(bi)去(qu)年(nian)(nian)(nian)(nian)略(lve)低，但當陽、天門(men)、黃(huang)陂等地基(ji)數(shu)大幅增加(jia)，如當陽平(ping)(ping)均每(mei)畝(mu)活(huo)蟲(chong)量達到17656頭(tou)，比(bi)(bi)(bi)去(qu)年(nian)(nian)(nian)(nian)增加(jia)了235%，比(bi)(bi)(bi)歷(li)年(nian)(nian)(nian)(nian)增加(jia)141%；天門(men)加(jia)權(quan)平(ping)(ping)均每(mei)畝(mu)活(huo)蟲(chong)基(ji)數(shu)達到11458.32頭(tou)，比(bi)(bi)(bi)去(qu)年(nian)(nian)(nian)(nian)增加(jia)了52.17%，比(bi)(bi)(bi)歷(li)年(nian)(nian)(nian)(nian)增加(jia)61%。鄂(e)東每(mei)畝(mu)活(huo)蟲(chong)基(ji)數(shu)2656-4850頭(tou), 加(jia)權(quan)平(ping)(ping)均3741.77頭(tou)，比(bi)(bi)(bi)去(qu)年(nian)(nian)(nian)(nian)降(jiang)低49.43%；鄂(e)北隨州、襄樊平(ping)(ping)均畝(mu)活(huo)蟲(chong)基(ji)數(shu)1051.2頭(tou)，與去(qu)年(nian)(nian)(nian)(nian)基(ji)本持平(ping)(ping)，比(bi)(bi)(bi)常年(nian)(nian)(nian)(nian)增加(jia)38%。鄂(e)西南加(jia)權(quan)平(ping)(ping)均每(mei)畝(mu)活(huo)蟲(chong)數(shu)2107.77頭(tou),是去(qu)年(nian)(nian)(nian)(nian)同期的72.18倍。鄂(e)西北十堰(yan)每(mei)畝(mu)活(huo)蟲(chong)基(ji)數(shu)0-5520頭(tou)，平(ping)(ping)均1451.61頭(tou)，比(bi)(bi)(bi)去(qu)年(nian)(nian)(nian)(nian)同期降(jiang)低57.3%。
（二(er)）發育(yu)進(jin)度：江漢(han)平原仙(xian)桃市4月(yue)22日(ri)剝(bo)(bo)查(cha)，冬閑田老(lao)(lao)熟(shu)(shu)幼(you)(you)蟲(chong)(chong)(chong)187頭(tou)，化(hua)(hua)蛹(yong)(yong)(yong)(yong)(yong)(yong)率(lv)35.65%，其中(zhong)(zhong)預(yu)蛹(yong)(yong)(yong)(yong)(yong)(yong)至(zhi)6級(ji)蛹(yong)(yong)(yong)(yong)(yong)(yong)所占(zhan)比(bi)(bi)例(li)(li)(li)分(fen)別(bie)(bie)為(wei)(wei)5.36%、11.67%、14.83%、4.41%、4.10%、0.63%、0；小麥(mai)田老(lao)(lao)熟(shu)(shu)幼(you)(you)蟲(chong)(chong)(chong)82頭(tou)，化(hua)(hua)蛹(yong)(yong)(yong)(yong)(yong)(yong)率(lv)22.12%，其中(zhong)(zhong)預(yu)蛹(yong)(yong)(yong)(yong)(yong)(yong)至(zhi)6級(ji)蛹(yong)(yong)(yong)(yong)(yong)(yong)所占(zhan)比(bi)(bi)例(li)(li)(li)分(fen)別(bie)(bie)為(wei)(wei)5.31%、8.85%、5.31%、1.77%、3.54%、2.65%、0；油菜田老(lao)(lao)熟(shu)(shu)幼(you)(you)蟲(chong)(chong)(chong)39頭(tou)，化(hua)(hua)蛹(yong)(yong)(yong)(yong)(yong)(yong)率(lv)為(wei)(wei)20%，1～6級(ji)蛹(yong)(yong)(yong)(yong)(yong)(yong)所占(zhan)比(bi)(bi)例(li)(li)(li)分(fen)別(bie)(bie)為(wei)(wei)2%、4%、10%、2%、4%、0。鄂東羅田、蘄(qi)春、紅安剝(bo)(bo)查(cha)，冬閑田老(lao)(lao)熟(shu)(shu)幼(you)(you)蟲(chong)(chong)(chong)98頭(tou)，化(hua)(hua)蛹(yong)(yong)(yong)(yong)(yong)(yong)率(lv)為(wei)(wei)39.9%，其中(zhong)(zhong)預(yu)蛹(yong)(yong)(yong)(yong)(yong)(yong)至(zhi)5級(ji)蛹(yong)(yong)(yong)(yong)(yong)(yong)所占(zhan)比(bi)(bi)例(li)(li)(li)分(fen)別(bie)(bie)為(wei)(wei)6.8%、6.8%、10.4%、11.1%、4.3%、0.6%；小麥(mai)田老(lao)(lao)熟(shu)(shu)幼(you)(you)蟲(chong)(chong)(chong)22頭(tou)，化(hua)(hua)蛹(yong)(yong)(yong)(yong)(yong)(yong)率(lv)為(wei)(wei)51.1%，預(yu)蛹(yong)(yong)(yong)(yong)(yong)(yong)至(zhi)3級(ji)蛹(yong)(yong)(yong)(yong)(yong)(yong)所占(zhan)比(bi)(bi)例(li)(li)(li)分(fen)別(bie)(bie)為(wei)(wei)20%、11.1%、13.3%、6.7%、；油菜田老(lao)(lao)熟(shu)(shu)幼(you)(you)蟲(chong)(chong)(chong)33頭(tou)，化(hua)(hua)蛹(yong)(yong)(yong)(yong)(yong)(yong)率(lv)為(wei)(wei)46.8%，預(yu)蛹(yong)(yong)(yong)(yong)(yong)(yong)至(zhi)4級(ji)蛹(yong)(yong)(yong)(yong)(yong)(yong)所占(zhan)比(bi)(bi)例(li)(li)(li)分(fen)別(bie)(bie)為(wei)(wei)9.7%、12.9%、12.9%、8.1%、3.2%。鄂北(bei)襄州區4月(yue)22日(ri)剝(bo)(bo)查(cha)，幼(you)(you)蟲(chong)(chong)(chong)46頭(tou)，化(hua)(hua)蛹(yong)(yong)(yong)(yong)(yong)(yong)率(lv)3.34%，其中(zhong)(zhong)預(yu)蛹(yong)(yong)(yong)(yong)(yong)(yong)至(zhi)6級(ji)蛹(yong)(yong)(yong)(yong)(yong)(yong)所占(zhan)比(bi)(bi)例(li)(li)(li)分(fen)別(bie)(bie)為(wei)(wei)16.67%、0、0、1.67%、0、0、0，羽(yu)化(hua)(hua)率(lv)1.67%。
（三(san)）水稻(dao)耕作制度和栽培(pei)措施有(you)利其發(fa)生。近年來全省大(da)(da)(da)力(li)推廣(guang)輕(qing)簡栽培(pei)技術，水稻(dao)機(ji)收面(mian)積擴大(da)(da)(da)，冬種油菜小麥又(you)給(gei)二(er)(er)化(hua)螟(ming)提(ti)供了補充食源(yuan)(yuan)，大(da)(da)(da)大(da)(da)(da)有(you)利于二(er)(er)化(hua)螟(ming)的越冬存(cun)活，提(ti)高了有(you)效蟲源(yuan)(yuan)基數(shu)。冬閑田面(mian)積的擴大(da)(da)(da)，對蟲源(yuan)(yuan)基數(shu)和發(fa)育(yu)進度產生了很(hen)大(da)(da)(da)的影(ying)響，造成一代二(er)(er)化(hua)螟(ming)的發(fa)生期拉長。
（四(si)）氣候(hou)對水稻(dao)二化(hua)螟的(de)發生無不利(li)影(ying)響。4月中(zhong)下旬湖北大(da)部(bu)(bu)高溫少雨，有利(li)于二化(hua)螟的(de)化(hua)蛹羽化(hua)，轉化(hua)存活率高。據中(zhong)央(yang)氣象臺預報，4月底(di)至5月中(zhong)旬我省大(da)部(bu)(bu)地區氣溫正(zheng)(zheng)常(chang)略(lve)偏高，南部(bu)(bu)降雨正(zheng)(zheng)常(chang)略(lve)偏多，北部(bu)(bu)降雨正(zheng)(zheng)常(chang)略(lve)偏少，局(ju)部(bu)(bu)地區出現輕旱(han)，有利(li)于二化(hua)螟的(de)產(chan)卵孵化(hua)。
各地(di)要因地(di)制宜，切(qie)實(shi)做好“兩(liang)查兩(liang)定”，及時發布短期預報，分類指導田間防治。
湖北省植保總站
