棉鈴蟲:幼蟲棉鈴蟲成蟲、蛹及卵棉鈴蟲也叫鉆心蟲,是大害蟲。棉鈴蟲的食性雜、寄主種類多,近幾年,絕大多數綠色植物上都有棉鈴蟲的卵和幼蟲為害,而且對玉米的為害也(ye)呈明(ming)顯(xian)加重趨勢(shi)。
1、形(xing)(xing)態:成蟲體長16~17毫(hao)米(mi),前翅顏色(se)(se)(se)(se)(se)變化(hua)較(jiao)大(da),雌蛾多黃(huang)褐(he)色(se)(se)(se)(se)(se),雄蛾多綠(lv)褐(he)色(se)(se)(se)(se)(se),外橫(heng)線有深灰色(se)(se)(se)(se)(se)寬帶,帶上有7個小白點,腎形(xing)(xing)紋和環形(xing)(xing)紋暗褐(he)色(se)(se)(se)(se)(se)。卵(luan)半球形(xing)(xing),初產時(shi)乳白色(se)(se)(se)(se)(se),直徑0.5~0.8毫(hao)米(mi)。幼蟲體長40~45毫(hao)米(mi),頭部黃(huang)褐(he)色(se)(se)(se)(se)(se)變化(hua)很大(da),大(da)致可分為黃(huang)白色(se)(se)(se)(se)(se)型(xing)、黃(huang)紅色(se)(se)(se)(se)(se)型(xing)、灰褐(he)色(se)(se)(se)(se)(se)型(xing)、土(tu)黃(huang)色(se)(se)(se)(se)(se)型(xing)、淡紅色(se)(se)(se)(se)(se)型(xing)、綠(lv)色(se)(se)(se)(se)(se)型(xing)、黑褐(he)色(se)(se)(se)(se)(se)型(xing)、咖啡色(se)(se)(se)(se)(se)型(xing)、綠(lv)褐(he)色(se)(se)(se)(se)(se)型(xing)等9種(zhong)類型(xing)。蛹紡(fang)錘形(xing)(xing),長17~20毫(hao)米(mi),第(di)5~7腹節(jie)前緣密布(bu)比體色(se)(se)(se)(se)(se)略(lve)深的刻(ke)點,尾端(duan)有臀刺2枚。
2、發(fa)(fa)生(sheng)(sheng)規律:第(di)一代成(cheng)蟲(chong)(chong)(chong)始見(jian)于(yu)6月(yue)上(shang)中(zhong)(zhong)旬(xun),中(zhong)(zhong)下旬(xun)盛發(fa)(fa);第(di)二代成(cheng)蟲(chong)(chong)(chong)始見(jian)于(yu)7月(yue)上(shang)中(zhong)(zhong)旬(xun),盛發(fa)(fa)于(yu)中(zhong)(zhong)下旬(xun);第(di)三代成(cheng)蟲(chong)(chong)(chong)始見(jian)于(yu)8月(yue)上(shang)中(zhong)(zhong)旬(xun)。以第(di)四代滯育(yu)蛹越(yue)冬。成(cheng)蟲(chong)(chong)(chong)有趨光性,對半枯(ku)萎的(de)(de)(de)楊樹枝(zhi)把也有很(hen)強的(de)(de)(de)趨性,成(cheng)蟲(chong)(chong)(chong)產卵(luan)(luan)量(liang)(liang)平(ping)均1000余粒,在(zai)(zai)生(sheng)(sheng)長旺盛茂密且(qie)抽穗(sui)早的(de)(de)(de)玉米田比長勢差的(de)(de)(de)玉米田產卵(luan)(luan)量(liang)(liang)明顯增多(duo)。產卵(luan)(luan)部位多(duo)在(zai)(zai)雌穗(sui)剛吐出(chu)的(de)(de)(de)花(hua)絲上(shang)和剛抽出(chu)的(de)(de)(de)雄穗(sui)上(shang)。幼(you)(you)(you)蟲(chong)(chong)(chong)孵化(hua)后(hou)(hou)先食卵(luan)(luan)殼,以后(hou)(hou)取食幼(you)(you)(you)嫩的(de)(de)(de)花(hua)絲或雄穗(sui),也取食葉(xie)(xie)片。幼(you)(you)(you)蟲(chong)(chong)(chong)3齡前多(duo)在(zai)(zai)外(wai)面活(huo)動(dong)為(wei)害(hai),這是施藥防治(zhi)的(de)(de)(de)有利時機,3齡以后(hou)(hou)多(duo)鉆蛀到苞葉(xie)(xie)內為(wei)害(hai)玉米穗(sui),取食量(liang)(liang)和對玉米穗(sui)的(de)(de)(de)為(wei)害(hai)程度明顯比玉米螟大,也不易防治(zhi)。幼(you)(you)(you)蟲(chong)(chong)(chong)共6齡,末(mo)齡幼(you)(you)(you)蟲(chong)(chong)(chong)入土化(hua)蛹。棉鈴蟲(chong)(chong)(chong)喜(xi)中(zhong)(zhong)溫(wen)高濕,各蟲(chong)(chong)(chong)態發(fa)(fa)育(yu)的(de)(de)(de)最適溫(wen)度為(wei)25~ 28℃ ,相(xiang)對濕度為(wei)70~90%,6~8月(yue)份降(jiang)水(shui)量(liang)(liang)達100~150毫(hao)米的(de)(de)(de)年(nian)份,利于(yu)棉鈴蟲(chong)(chong)(chong)的(de)(de)(de)嚴(yan)重(zhong)發(fa)(fa)生(sheng)(sheng)。
3、防治(zhi)方法:①玉米收(shou)獲后,及時深翻耙地,堅持實行冬灌,可(ke)(ke)(ke)大(da)量(liang)(liang)消滅越冬蛹。②合理布局。在(zai)(zai)棉田(tian)地邊種(zhong)少量(liang)(liang)春(chun)玉米或(huo)(huo)高粱,既可(ke)(ke)(ke)誘集(ji)較多的(de)棉鈴(ling)(ling)蟲(chong)(chong)來產卵,又(you)能誘集(ji)大(da)量(liang)(liang)天敵(di)存活繁殖(zhi),對(dui)棉鈴(ling)(ling)蟲(chong)(chong)有明顯的(de)控制(zhi)(zhi)作(zuo)用(yong)。在(zai)(zai)玉米地邊種(zhong)植(zhi)誘集(ji)作(zuo)物(wu)如洋蔥、胡蘿卜等,于盛(sheng)花期(qi)(qi)(qi)可(ke)(ke)(ke)誘集(ji)到大(da)量(liang)(liang)棉鈴(ling)(ling)蟲(chong)(chong)成(cheng)蟲(chong)(chong),及時噴藥,聚(ju)而殲(jian)之。于各(ge)代(dai)棉鈴(ling)(ling)蟲(chong)(chong)成(cheng)蟲(chong)(chong)發生(sheng)期(qi)(qi)(qi),在(zai)(zai)田(tian)間(jian)設置(zhi)黑(hei)光燈,性誘劑或(huo)(huo)楊樹枝把,可(ke)(ke)(ke)大(da)量(liang)(liang)誘殺成(cheng)蟲(chong)(chong)。③在(zai)(zai)棉鈴(ling)(ling)蟲(chong)(chong)卵盛(sheng)期(qi)(qi)(qi),人工飼養釋(shi)放赤眼(yan)蜂(feng)或(huo)(huo)草蛉,發揮天敵(di)的(de)自然控制(zhi)(zhi)作(zuo)用(yong)。也可(ke)(ke)(ke)在(zai)(zai)卵盛(sheng)期(qi)(qi)(qi)噴施每毫升(sheng)含100億個以(yi)上孢(bao)子的(de)Bt乳劑100倍液(ye)(ye),或(huo)(huo)噴施棉鈴(ling)(ling)蟲(chong)(chong)核多角體病毒(NPV)1000倍液(ye)(ye)。④化學防治(zhi)可(ke)(ke)(ke)在(zai)(zai)幼蟲(chong)(chong)3齡以(yi)前,用(yong)75%拉維(wei)因3000倍液(ye)(ye),或(huo)(huo)用(yong)50%甲胺膦1000倍液(ye)(ye),或(huo)(huo)50%辛硫磷1000倍液(ye)(ye),均勻(yun)噴霧(wu)。












