由于(yu)今年草地(di)(di)螟(ming)一代(dai)幼蟲(chong)(chong)(chong)發生面(mian)積小(xiao)、密(mi)度(du)(du)低、殘(can)蟲(chong)(chong)(chong)量少(shao)，一代(dai)成(cheng)蟲(chong)(chong)(chong)尚未出現蛾峰，預(yu)計全(quan)國草地(di)(di)螟(ming)二代(dai)幼蟲(chong)(chong)(chong)總(zong)體(ti)輕發生，農田(tian)及(ji)其周邊發生面(mian)積為100萬(wan)畝，主要發生區域為內蒙古(gu)中(zhong)東部(bu)、吉林西(xi)部(bu)、河北(bei)、山西(xi)、陜西(xi)和(he)寧夏四省(sheng)（區）的北(bei)部(bu)、新(xin)疆阿勒泰、塔城(cheng)及(ji)和(he)田(tian)地(di)(di)區；發生為害盛期為8月上、中(zhong)旬(xun)。同時，近(jin)期東北(bei)地(di)(di)區、華北(bei)北(bei)部(bu)多(duo)陣(zhen)性降雨(yu)，不(bu)排除俄羅斯、蒙古(gu)等周邊國家存在高(gao)密(mi)度(du)(du)蟲(chong)(chong)(chong)源，遇適合氣流集中(zhong)遷入，造成(cheng)局部(bu)集中(zhong)為害的可能(neng)。
一、一代幼蟲輕發生(sheng)、重發區域少(shao)
2014年一(yi)代草地(di)螟總體輕(qing)(qing)發(fa)(fa)(fa)生，是2001年以來發(fa)(fa)(fa)生最輕(qing)(qing)的(de)年份(fen)。初步(bu)統計，越冬代成蟲(chong)發(fa)(fa)(fa)生面積(ji)581.2萬畝，一(yi)代幼蟲(chong)發(fa)(fa)(fa)生面積(ji)115.6萬畝，其(qi)中(zhong)，內蒙古中(zhong)西(xi)(xi)部(bu)和東(dong)南部(bu)（巴彥(yan)淖爾市(shi)、鄂(e)爾多斯市(shi)、烏蘭(lan)察布市(shi)、呼和浩特市(shi)、錫林(lin)郭勒(le)盟(meng)、赤(chi)峰市(shi)、興安(an)盟(meng)）、新(xin)疆北(bei)疆（阿勒(le)泰(tai)地(di)區、塔城地(di)區）偏輕(qing)(qing)發(fa)(fa)(fa)生，河(he)北(bei)北(bei)部(bu)、山西(xi)(xi)北(bei)部(bu)、寧(ning)夏北(bei)部(bu)、吉林(lin)西(xi)(xi)部(bu)、新(xin)疆博州與和田輕(qing)(qing)發(fa)(fa)(fa)生，陜西(xi)(xi)北(bei)部(bu)零星發(fa)(fa)(fa)生，遼寧(ning)、黑龍江未發(fa)(fa)(fa)生。
大(da)部(bu)(bu)區(qu)(qu)域一代幼(you)蟲(chong)(chong)(chong)(chong)(chong)發(fa)生期(qi)為6月中(zhong)(zhong)、下旬，比常年(nian)偏晚(wan)，且(qie)發(fa)生密(mi)(mi)(mi)度(du)(du)低(di)(di)，僅(jin)在(zai)內蒙古中(zhong)(zhong)東部(bu)(bu)、新疆北(bei)部(bu)(bu)、河北(bei)北(bei)部(bu)(bu)、山(shan)西北(bei)部(bu)(bu)出現較(jiao)高(gao)密(mi)(mi)(mi)度(du)(du)田(tian)(tian)(tian)塊。如(ru)內蒙古呼(hu)和(he)浩特市(shi)托(tuo)克(ke)托(tuo)縣(xian)800畝玉(yu)米(mi)(mi)(mi)田(tian)(tian)(tian)百株蟲(chong)(chong)(chong)(chong)(chong)量(liang)2200-3400頭(tou)，賽罕區(qu)(qu)、土(tu)左(zuo)旗、和(he)林(lin)縣(xian)苜蓿田(tian)(tian)(tian)幼(you)蟲(chong)(chong)(chong)(chong)(chong)密(mi)(mi)(mi)度(du)(du)30-40頭(tou)/m2，高(gao)的(de)(de)達(da)60-80頭(tou)/㎡；鄂爾(er)多斯(si)市(shi)達(da)拉特旗20 m2的(de)(de)玉(yu)米(mi)(mi)(mi)田(tian)(tian)(tian)灰菜(cai)上(shang)平(ping)均蟲(chong)(chong)(chong)(chong)(chong)口密(mi)(mi)(mi)度(du)(du)200頭(tou)/m2，最(zui)高(gao)達(da)240頭(tou)/m2；赤峰市(shi)阿魯科爾(er)沁旗玉(yu)米(mi)(mi)(mi)田(tian)(tian)(tian)百株蟲(chong)(chong)(chong)(chong)(chong)量(liang)60-80頭(tou)，重發(fa)地(di)塊200-300頭(tou)；錫林(lin)郭勒盟太仆(pu)寺旗灰菜(cai)較(jiao)多的(de)(de)胡(hu)(hu)麻田(tian)(tian)(tian)、馬鈴(ling)薯田(tian)(tian)(tian)幼(you)蟲(chong)(chong)(chong)(chong)(chong)平(ping)均密(mi)(mi)(mi)度(du)(du)13頭(tou)/m2，最(zui)高(gao)30頭(tou)/m2。新疆阿勒泰地(di)區(qu)(qu)苜蓿田(tian)(tian)(tian)平(ping)均密(mi)(mi)(mi)度(du)(du)2頭(tou)/m2，最(zui)高(gao)60頭(tou)/m2；塔城地(di)區(qu)(qu)玉(yu)米(mi)(mi)(mi)田(tian)(tian)(tian)幼(you)蟲(chong)(chong)(chong)(chong)(chong)平(ping)均密(mi)(mi)(mi)度(du)(du)5頭(tou)/m2，最(zui)高(gao)160頭(tou)/m2。河北(bei)康(kang)保縣(xian)具有灌(guan)溉(gai)條(tiao)件(jian)且(qie)雜(za)草(cao)較(jiao)多的(de)(de)亞(ya)麻、豆類(lei)、青貯玉(yu)米(mi)(mi)(mi)、甜菜(cai)、胡(hu)(hu)蘿(luo)卜的(de)(de)田(tian)(tian)(tian)塊中(zhong)(zhong)幼(you)蟲(chong)(chong)(chong)(chong)(chong)平(ping)均密(mi)(mi)(mi)度(du)(du)35.5頭(tou)/m2,最(zui)高(gao)839.9頭(tou)/m2。山(shan)西北(bei)部(bu)(bu)陽高(gao)縣(xian)、應(ying)縣(xian)、繁峙(zhi)縣(xian)的(de)(de)苜蓿地(di)和(he)田(tian)(tian)(tian)邊地(di)楞、草(cao)地(di)中(zhong)(zhong)幼(you)蟲(chong)(chong)(chong)(chong)(chong)平(ping)均密(mi)(mi)(mi)度(du)(du)3-5頭(tou)/m2，其中(zhong)(zhong)應(ying)縣(xian)300畝左(zuo)右玉(yu)米(mi)(mi)(mi)田(tian)(tian)(tian)灰菜(cai)上(shang)最(zui)高(gao)80頭(tou)/m2。新疆和(he)田(tian)(tian)(tian)地(di)區(qu)(qu)、博(bo)州、寧夏惠農區(qu)(qu)、吉林(lin)前郭縣(xian)幼(you)蟲(chong)(chong)(chong)(chong)(chong)密(mi)(mi)(mi)度(du)(du)低(di)(di)，不(bu)足1頭(tou)/m2。
二、一代(dai)幼蟲殘留面(mian)積(ji)小(xiao)、密度低
一代(dai)幼蟲(chong)田間密度低，達標面(mian)(mian)(mian)積(ji)(ji)小，殘(can)(can)留蟲(chong)源量低，構成(cheng)二代(dai)幼蟲(chong)較(jiao)大(da)范圍較(jiao)重發生的威脅較(jiao)小。全國(guo)一代(dai)幼蟲(chong)防治面(mian)(mian)(mian)積(ji)(ji)44.3萬(wan)(wan)(wan)畝，防治后(hou)殘(can)(can)蟲(chong)面(mian)(mian)(mian)積(ji)(ji)42.3萬(wan)(wan)(wan)畝，內蒙古、新疆、山西、河(he)北、寧夏和吉林等(deng)省（區(qu)）面(mian)(mian)(mian)積(ji)(ji)分(fen)別(bie)為(wei)21.7萬(wan)(wan)(wan)畝、9.0萬(wan)(wan)(wan)畝、7.7萬(wan)(wan)(wan)畝、3.0萬(wan)(wan)(wan)畝、0.8萬(wan)(wan)(wan)畝、0.1萬(wan)(wan)(wan)畝，每平方米殘(can)(can)蟲(chong)量分(fen)別(bie)為(wei)3.6頭、0.3頭、3.5頭、0.01頭、0.1頭、0.1頭。
三、一代成(cheng)蟲始見晚、蛾量低
7月初以來，一(yi)代(dai)成(cheng)(cheng)(cheng)蟲陸續在陜西(xi)(xi)北部(bu)、寧夏北部(bu)、山(shan)西(xi)(xi)北部(bu)、內蒙古中西(xi)(xi)部(bu)和吉(ji)林(lin)西(xi)(xi)部(bu)始見(jian)，大部(bu)地區為(wei)零星發(fa)(fa)生(sheng)。目(mu)前全國一(yi)代(dai)成(cheng)(cheng)(cheng)蟲發(fa)(fa)生(sheng)面積為(wei)31.1萬畝(mu)，發(fa)(fa)生(sheng)區域(yu)主要為(wei)陜西(xi)(xi)榆林(lin)市(shi)、寧夏惠農區、山(shan)西(xi)(xi)陽高縣、內蒙古呼和浩(hao)特(te)市(shi)、錫林(lin)郭(guo)勒盟、巴彥淖爾市(shi)、吉(ji)林(lin)乾安縣；發(fa)(fa)生(sheng)區一(yi)代(dai)成(cheng)(cheng)(cheng)蟲單燈累計誘蛾量為(wei)幾頭(tou)至幾十(shi)頭(tou)，田間百步驚蛾量僅為(wei)幾頭(tou)。
四(si)、部分地區氣象條(tiao)件有利于(yu)草地螟的遷(qian)入和發生(sheng)
據國(guo)家氣候中心預測，夏季（6-8月份），內蒙(meng)古東部(bu)、黑龍(long)江大部(bu)、新疆北部(bu)降水偏多，且(qie)7月底至8月上(shang)旬，東北地(di)區(qu)、華北北部(bu)多陣性降雨，有(you)利(li)于以上(shang)地(di)區(qu)草地(di)螟(ming)的(de)遷入和發生。
鑒于草地螟具突發為害特點，發生區域和時間存在一定的不確定性，各地應繼續密切監測，及時了解當地和周邊地區蟲情發生動態，特別是要注意燈下、田間蛾量系統調查和雌蛾卵巢發育進度剖查，以掌握分布區域、種群規模、發育進度和能否宿留情況，準確發布短期預報，指導農民做好防治，保障秋季作物的安全生產。
