根(gen)據(ju)我省當(dang)地一(yi)代草(cao)(cao)地螟(ming)發生、近日蛾量調(diao)查(cha)、結合(he)外地蟲(chong)源和(he)氣(qi)象(xiang)預報,預測我省二代草(cao)(cao)地螟(ming)總(zong)體中(zhong)等偏輕至中(zhong)等發生,局(ju)部將(jiang)出現(xian)蟲(chong)口(kou)密(mi)度高的田塊(kuai)。主要依(yi)據(ju):
1、我省(sheng)當地(di)一代草地(di)螟(ming)(ming)發(fa)生輕(qing)(qing),自然(ran)死亡率(lv)高(gao),殘蟲(chong)(chong)(chong)數量低(di)。受今年我省(sheng)越冬(dong)代草地(di)螟(ming)(ming)成蟲(chong)(chong)(chong)數量小(xiao)(xiao),異地(di)蟲(chong)(chong)(chong)源(yuan)遷(qian)入少,環境條件不適(shi)宜(yi)等因素影響,一代草地(di)螟(ming)(ming)發(fa)生面積(ji)小(xiao)(xiao)、幼蟲(chong)(chong)(chong)密度低(di)、危(wei)害輕(qing)(qing)。康保縣一代草地(di)螟(ming)(ming)幼蟲(chong)(chong)(chong)有蟲(chong)(chong)(chong)面積(ji) 3.0萬畝,平均幼蟲(chong)(chong)(chong)密度0.4頭/m2,最(zui)高(gao)5頭/m2(撂荒地(di)、草場),在張紀鎮王洪(hong)禮科技園(yuan)區噴灌區地(di)埂(geng)灰(hui)菜上發(fa)現有高(gao)密度幼蟲(chong)(chong)(chong)發(fa)生,但面積(ji)小(xiao)(xiao)。幼蟲(chong)(chong)(chong)自然(ran)死亡率(lv)高(gao)達(da)76.7%,當地(di)一代殘蟲(chong)(chong)(chong)量低(di)。8月(yue)5日,當地(di)一代草地(di)螟(ming)(ming)羽(yu)化(hua)率(lv)為69.0%,8月(yue)9日,羽(yu)化(hua)率(lv)為96.2%。
2、我國(guo)境內蟲源數量(liang)少,境外蟲源數量(liang)不清。據全國(guo)農(nong)技中心(xin)通(tong)報,截止8月5日, 新疆阿(a)勒泰(tai)二代幼蟲發生(sheng)(sheng)8.75萬(wan)畝(mu)(較上年偏早(zao)10天),塔城(cheng)盆地發生(sheng)(sheng)3.85萬(wan)畝(mu),甜菜、打瓜田(tian)(tian)平(ping)均密度(du)1-5頭/㎡,地頭田(tian)(tian)邊及雜草蟲口(kou)密度(du)高于農(nong)田(tian)(tian)。山西大同市(shi)、寧夏(xia)惠農(nong)、吉(ji)林松原有(you)二代幼蟲發生(sheng)(sheng)。內蒙古暫(zan)未發現。
3、近日(ri)發(fa)(fa)(fa)現有(you)異地(di)草地(di)螟成(cheng)(cheng)蟲(chong)(chong)大量(liang)(liang)(liang)(liang)(liang)(liang)遷入(ru),局(ju)部田(tian)(tian)間(jian)蛾(e)量(liang)(liang)(liang)(liang)(liang)(liang)偏高(gao)(gao)(gao)。近日(ri)北部草地(di)螟常發(fa)(fa)(fa)區(qu)出(chu)(chu)現降(jiang)雨(yu)(yu),降(jiang)雨(yu)(yu)量(liang)(liang)(liang)(liang)(liang)(liang)差異較大,造成(cheng)(cheng)草地(di)螟成(cheng)(cheng)蟲(chong)(chong)量(liang)(liang)(liang)(liang)(liang)(liang)分(fen)布不均(jun),總體上(shang)降(jiang)雨(yu)(yu)多的(de)地(di)方(fang)成(cheng)(cheng)蟲(chong)(chong)量(liang)(liang)(liang)(liang)(liang)(liang)高(gao)(gao)(gao),降(jiang)雨(yu)(yu)量(liang)(liang)(liang)(liang)(liang)(liang)少的(de)地(di)方(fang)成(cheng)(cheng)蟲(chong)(chong)量(liang)(liang)(liang)(liang)(liang)(liang)低。康(kang)保縣8月(yue)(yue)9日(ri)至11日(ri)普查(cha),滿(man)德堂鄉、牧(mu)場降(jiang)雨(yu)(yu)量(liang)(liang)(liang)(liang)(liang)(liang)分(fen)別(bie)為56.4毫米(mi)(mi)和(he)44.5毫米(mi)(mi),農牧(mu)交(jiao)錯(cuo)區(qu)百步驚蛾(e)1000-2000頭(tou)(tou),最(zui)高(gao)(gao)(gao)3000頭(tou)(tou);康(kang)保鎮和(he)照陽河鎮降(jiang)雨(yu)(yu)量(liang)(liang)(liang)(liang)(liang)(liang)分(fen)別(bie)為25.1毫米(mi)(mi)和(he)21.8毫米(mi)(mi),農牧(mu)交(jiao)錯(cuo)區(qu)百步驚蛾(e)500-1000頭(tou)(tou),最(zui)高(gao)(gao)(gao)2000頭(tou)(tou);南部鄉鎮哈咇嘎(ga)鄉、土城子鎮、鄧(deng)油坊鎮降(jiang)雨(yu)(yu)量(liang)(liang)(liang)(liang)(liang)(liang)0.1-1.1毫米(mi)(mi),田(tian)(tian)間(jian)可零星見到成(cheng)(cheng)蟲(chong)(chong)。全縣一代(dai)草地(di)螟成(cheng)(cheng)蟲(chong)(chong)發(fa)(fa)(fa)生15萬畝左右,主要發(fa)(fa)(fa)生在農牧(mu)交(jiao)錯(cuo)區(qu)。另(ling)據(ju)黑(hei)光燈誘測,8月(yue)(yue)9日(ri)出(chu)(chu)現誘蛾(e)高(gao)(gao)(gao)峰,一盞(zhan)黑(hei)光燈日(ri)誘蛾(e)817頭(tou)(tou),其中雌(ci)蛾(e)605頭(tou)(tou),1、2級(ji)(ji)卵(luan)(luan)巢占100%。8月(yue)(yue)10日(ri)誘蛾(e)183頭(tou)(tou),雌(ci)蛾(e)多為二(er)級(ji)(ji),少量(liang)(liang)(liang)(liang)(liang)(liang)三級(ji)(ji)(田(tian)(tian)間(jian)三級(ji)(ji)雌(ci)蛾(e)比例偏高(gao)(gao)(gao)),抱卵(luan)(luan)量(liang)(liang)(liang)(liang)(liang)(liang)偏少。8月(yue)(yue)11日(ri)田(tian)(tian)間(jian)發(fa)(fa)(fa)現新產的(de)二(er)代(dai)草地(di)螟卵(luan)(luan),多數每塊(kuai)2-3粒,少數卵(luan)(luan)塊(kuai)10粒左右。
4、近期(qi)降雨較(jiao)多,田間濕度大(da)。據省(sheng)(sheng)氣象臺預報,全省(sheng)(sheng)8月12—14日(ri),16—17日(ri),20—21日(ri)有三(san)次較(jiao)大(da)降雨過程,利(li)于外地草地螟成蟲(chong)遷入、產卵孵化和幼蟲(chong)發生危害。
預計草地螟產卵(luan)始期(qi)8月(yue)11日,盛(sheng)峰期(qi)8月(yue)13日左右,田間二(er)代幼蟲(chong)始見(jian)期(qi)為(wei)8月(yue)15日,盛(sheng)峰期(qi)為(wei)8月(yue)17日,發生(sheng)危(wei)害期(qi)8月(yue)15至9月(yue)15日。康保縣(xian)幼蟲(chong)發生(sheng)面(mian)積15畝(mu)左右,達到防(fang)治指標面(mian)積10萬(wan)畝(mu)左右。
各地一定要加強調查監測,及時開展大面積普查,特別是張家口、承德草地螟常發區要進一步加大調查監測工作力度,密切關注草地螟成蟲、幼蟲發生動態,剖查雌蛾卵巢發育進度,及時發布蟲情預警,指導農民對達到防治指標的地塊及時防治。