七星瓢蟲(chong)(chong)(chong)(學名:Coccinella septempunctata)是瓢蟲(chong)(chong)(chong)科、瓢蟲(chong)(chong)(chong)屬昆蟲(chong)(chong)(chong)。成蟲(chong)(chong)(chong)體長5.2-6.5毫(hao)米,寬4.0-5.6毫(hao)米;身體卵圓形,背部拱起,呈(cheng)水瓢狀(zhuang);頭黑(hei)色(se)(se)(se)(se)(se)、復眼黑(hei)色(se)(se)(se)(se)(se),內側(ce)凹入(ru)處(chu)各有(you)一淡(dan)黃(huang)色(se)(se)(se)(se)(se)點(dian);觸角褐色(se)(se)(se)(se)(se);口器黑(hei)色(se)(se)(se)(se)(se);上額外側(ce)為黃(huang)色(se)(se)(se)(se)(se);前(qian)胸背板黑(hei),前(qian)上角各有(you)1個(ge)(ge)較(jiao)大(da)的(de)近方形的(de)淡(dan)黃(huang)地;小盾(dun)片(pian)黑(hei)色(se)(se)(se)(se)(se);鞘翅紅色(se)(se)(se)(se)(se)或橙(cheng)黃(huang)色(se)(se)(se)(se)(se),兩側(ce)共有(you)7個(ge)(ge)黑(hei)斑,左右(you)兩側(ce)各有(you)3個(ge)(ge)黑(hei)點(dian),接合處(chu)前(qian)方尚有(you)一個(ge)(ge)更大(da)的(de)黑(hei)點(dian);翅基(ji)部在小盾(dun)片(pian)兩側(ce)各有(you)1個(ge)(ge)三角形白斑;體腹及足黑(hei)色(se)(se)(se)(se)(se)。
七(qi)星(xing)瓢(piao)蟲(chong)一(yi)(yi)生(sheng)要經過卵、幼蟲(chong)、蛹(yong)和(he)成蟲(chong)4個不同(tong)發(fa)育階段,各蟲(chong)態的(de)發(fa)育歷期,主要受(shou)食(shi)物和(he)溫度(du)的(de)影(ying)響。七(qi)星(xing)瓢(piao)蟲(chong)是遷飛性(xing)昆蟲(chong),成蟲(chong)和(he)幼蟲(chong)的(de)覓食(shi)行為屬于廣(guang)域搜索(suo)(suo)與區域集中搜索(suo)(suo)行為的(de)轉(zhuan)換。七(qi)星(xing)瓢(piao)蟲(chong)主要以蚜蟲(chong)為食(shi),有時還取(qu)食(shi)小(xiao)土粒、真(zhen)菌(jun)孢子和(he)一(yi)(yi)些(xie)小(xiao)型昆蟲(chong),秋天(tian)還常常取(qu)食(shi)植物的(de)花粉。廣(guang)泛(fan)分(fen)布(bu)于非洲、歐洲、亞洲。
七星瓢蟲的(de)名(ming)稱由其(qi)(qi)鞘(qiao)翅上(shang)的(de)7個黑(hei)色斑(ban)(ban)點而來,但是(shi)其(qi)(qi)身(shen)上(shang)的(de)斑(ban)(ban)點數量是(shi)各不相同的(de)。
七(qi)星瓢(piao)蟲(chong)幼蟲(chong)與異(yi)(yi)色(se)(se)(se)瓢(piao)蟲(chong)幼蟲(chong)相(xiang)似。區別在于七(qi)星瓢(piao)蟲(chong)幼蟲(chong)淡藍灰(hui)色(se)(se)(se),異(yi)(yi)色(se)(se)(se)瓢(piao)蟲(chong)幼蟲(chong)灰(hui)黑(hei)色(se)(se)(se)。七(qi)星瓢(piao)蟲(chong)幼蟲(chong)腹部(bu)背面(mian)(mian)(mian)和側(ce)面(mian)(mian)(mian),每(mei)節生(sheng)有六個(ge)短刺(ci);第一(yi)(yi)、四(si)兩(liang)(liang)節背面(mian)(mian)(mian)兩(liang)(liang)側(ce),各(ge)(ge)有一(yi)(yi)對黃色(se)(se)(se)短刺(ci);其(qi)余(yu)各(ge)(ge)節短刺(ci)皆為黑(hei)色(se)(se)(se)。異(yi)(yi)色(se)(se)(se)瓢(piao)蟲(chong)幼蟲(chong)腹部(bu)背面(mian)(mian)(mian)兩(liang)(liang)側(ce),每(mei)節生(sheng)有六個(ge)分枝的(de)枝刺(ci),第四(si)兩(liang)(liang)節的(de)背面(mian)(mian)(mian)兩(liang)(liang)側(ce),各(ge)(ge)有一(yi)(yi)對桔紅(hong)色(se)(se)(se)枝刺(ci),其(qi)中第一(yi)(yi)節的(de)兩(liang)(liang)個(ge)枝刺(ci)基部(bu)相(xiang)連,形成(cheng)一(yi)(yi)個(ge)桔紅(hong)色(se)(se)(se)大斑。
某些(xie)金花蟲類的卵(luan)(luan),如(ru)柳葉甲(jia)(jia)的卵(luan)(luan)和七(qi)(qi)星(xing)瓢(piao)蟲的卵(luan)(luan)很相(xiang)似,常被誤認為七(qi)(qi)星(xing)瓢(piao)蟲卵(luan)(luan),但兩者是(shi)有明顯區別的:①兩者產(chan)(chan)(chan)卵(luan)(luan)習性不(bu)同,柳葉甲(jia)(jia)常在(zai)柳葉上產(chan)(chan)(chan)卵(luan)(luan),而(er)七(qi)(qi)星(xing)瓢(piao)蟲通常不(bu)在(zai)樹葉上產(chan)(chan)(chan)卵(luan)(luan);②柳葉甲(jia)(jia)卵(luan)(luan)粒是(shi)長圓形(xing),卵(luan)(luan)塊排列疏松而(er)不(bu)整(zheng)(zheng)齊,七(qi)(qi)星(xing)瓢(piao)蟲的卵(luan)(luan)粒是(shi)梭形(xing),排列緊密(mi)而(er)整(zheng)(zheng)齊。
七星瓢蟲(chong)廣泛分布(bu)于(yu)北(bei)(bei)美洲、歐洲、亞洲。在中國分布(bu)于(yu)東北(bei)(bei)、華北(bei)(bei)、華中、西北(bei)(bei)、華東和西南地區。
中文名 拉丁學名 命名者及(ji)年代
七星瓢蟲日本亞種 Coccinella septempunctata brucki Mulsant,1866
七星瓢蟲指名亞種 Coccinella septempunctata septempunctata Linnaeus,1758
七星瓢蟲體長5.2-7.0毫(hao)米(mi),寬4.0-5.6毫(hao)米(mi)。蟲體卵(luan)圓形,背面(mian)光滑并(bing)拱(gong)超呈半球狀(zhuang)。剛羽化的成蟲柔軟,嫩黃(huang)色,2-3小(xiao)時(shi)后,整個(ge)體軀(qu)和鞘(qiao)翅變硬,顏色由黃(huang)變紅,同(tong)時(shi)鞘(qiao)翅上出現7個(ge)黑色斑點。
七(qi)星(xing)瓢蟲和其它昆蟲一(yi)樣,體軀分(fen)(fen)為頭、胸(xiong)、腹(fu)三(san)(san)部(bu)(bu)(bu)分(fen)(fen)。各部(bu)(bu)(bu)分(fen)(fen)均由若干個(ge)體節(jie)(jie)(jie)組成。頭部(bu)(bu)(bu)生有(you)一(yi)對觸(chu)角(jiao),一(yi)對復眼和口器(qi)(qi),口器(qi)(qi)兩側(ce)有(you)一(yi)對下(xia)顎須。頭部(bu)(bu)(bu)較小(xiao),經(jing)常后(hou)縮在發達的(de)前(qian)胸(xiong)背板(ban)之下(xia),胸(xiong)部(bu)(bu)(bu)生有(you)兩對翅(chi)(chi),三(san)(san)對足。腹(fu)部(bu)(bu)(bu)八節(jie)(jie)(jie),但腹(fu)面(mian)只能(neng)看到6一(yi)7節(jie)(jie)(jie)。腹(fu)部(bu)(bu)(bu)末端有(you)外生殖器(qi)(qi)和肛門。胸(xiong)部(bu)(bu)(bu)和腹(fu)部(bu)(bu)(bu)側(ce)面(mian)生有(you)氣(qi)孔,是(shi)呼吸時(shi)氣(qi)體進出的(de)通道,七(qi)星(xing)瓢蟲和許多(duo)有(you)硬翅(chi)(chi)鞘的(de)昆蟲(分(fen)(fen)類學上(shang)稱鞘翅(chi)(chi)目)一(yi)樣,有(you)一(yi)對角(jiao)質堅硬的(de)前(qian)翅(chi)(chi)。平時(shi),這一(yi)對的(de)翅(chi)(chi)并合,覆(fu)蓋在胸(xiong)腹(fu)部(bu)(bu)(bu)的(de)背上(shang)。后(hou)翅(chi)(chi)為半透(tou)明的(de)膜(mo)質,平時(shi)折(zhe)疊(die),匿(ni)于前(qian)翅(chi)(chi)之下(xia)。七(qi)星(xing)瓢蟲的(de)下(xia)顎須末節(jie)(jie)(jie)呈(cheng)斧狀,足的(de)咐節(jie)(jie)(jie)是(shi)四節(jie)(jie)(jie),但第三(san)(san)節(jie)(jie)(jie)特別小(xiao),并匿(ni)于第二(er)節(jie)(jie)(jie)的(de)兩個(ge)分(fen)(fen)葉(xie)之間,粗看很(hen)象是(shi)三(san)(san)節(jie)(jie)(jie)。
七(qi)星瓢(piao)蟲(chong)(chong)雌(ci)雄形(xing)態,斑紋相同,雌(ci)蟲(chong)(chong)常較雄蟲(chong)(chong)大(da)些。兩者(zhe)可靠的鑒別特(te)征是雄蟲(chong)(chong)腹(fu)(fu)部腹(fu)(fu)面(mian)末(mo)端,有一小的橫的凹陷,而(er)雌(ci)蟲(chong)(chong)則平坦而(er)光滑,無此(ci)凹陷。
七(qi)星瓢(piao)蟲(chong)幼(you)(you)蟲(chong)體表有(you)一(yi)(yi)層較堅硬(ying)的(de)表皮,它的(de)伸展性有(you)限,所(suo)以生(sheng)長到(dao)一(yi)(yi)定(ding)階段,必須蛻(tui)(tui)去老(lao)皮,著(zhu)生(sheng)新皮,才能繼(ji)續(xu)成長。每(mei)蛻(tui)(tui)一(yi)(yi)次(ci)(ci)皮,就(jiu)增加一(yi)(yi)個齡(ling)(ling)(ling)期(qi),幼(you)(you)蟲(chong)共蛻(tui)(tui)三次(ci)(ci)皮,有(you)四個齡(ling)(ling)(ling)期(qi)。初孵(fu)(fu)幼(you)(you)蟲(chong)(一(yi)(yi)齡(ling)(ling)(ling))身(shen)體很小,只(zhi)有(you)2-3毫米,孵(fu)(fu)化后,就(jiu)聚集在(zai)原卵塊的(de)殘殼上,約經8-12小時,開(kai)始分散取食。約兩天后,蛻(tui)(tui)皮變為二齡(ling)(ling)(ling),此(ci)時體長已(yi)增大(da)一(yi)(yi)倍多,腹(fu)部第一(yi)(yi)節(jie)背面兩側,出(chu)現兩個黃色肉(rou)瘤(liu)(liu),三齡(ling)(ling)(ling)幼(you)(you)蟲(chong)除體長加大(da)外,腹(fu)部第一(yi)(yi)、四兩節(jie)的(de)背面兩側,各有(you)一(yi)(yi)對黃色肉(rou)瘤(liu)(liu),但第四節(jie)的(de)肉(rou)瘤(liu)(liu)不很明(ming)顯(xian),要用放大(da)鏡才能看清(qing)楚,到(dao)四齡(ling)(ling)(ling)時,這兩對肉(rou)瘤(liu)(liu)都非(fei)常明(ming)顯(xian)。當幼(you)(you)蟲(chong)老(lao)熟時,體形變粗,最后以尾端固(gu)著(zhu)在(zai)植(zhi)株等附著(zhu)物上,準備化蛹。
體(ti)長7毫米,寬5毫米。體(ti)黃(huang)色。前胸(xiong)背(bei)板(ban)(ban)前緣有(you)(you)4個(ge)(ge)黑(hei)(hei)(hei)點,中(zhong)央(yang)2個(ge)(ge)呈三角形(xing),前胸(xiong)背(bei)板(ban)(ban)后緣中(zhong)央(yang)有(you)(you)2個(ge)(ge)黑(hei)(hei)(hei)點,兩側角有(you)(you)2個(ge)(ge)黑(hei)(hei)(hei)斑。中(zhong)胸(xiong)背(bei)板(ban)(ban)有(you)(you)2個(ge)(ge)黑(hei)(hei)(hei)斑。腹部(bu)第2-6節背(bei)面左(zuo)右有(you)(you)4個(ge)(ge)黑(hei)(hei)(hei)斑。腹末帶有(you)(you)末齡幼蟲的黑(hei)(hei)(hei)色蛻(tui)皮。
七(qi)(qi)星(xing)(xing)瓢蟲(chong)(chong)(chong)(chong)(chong)的(de)(de)下(xia)顎(e)須是它的(de)(de)主(zhu)要觸(chu)覺和(he)嗅覺器(qi)官。七(qi)(qi)星(xing)(xing)瓢蟲(chong)(chong)(chong)(chong)(chong)經常(chang)在蚜(ya)(ya)(ya)(ya)蟲(chong)(chong)(chong)(chong)(chong)的(de)(de)寄(ji)主(zhu)植物上(shang)爬(pa)動、搜索,當下(xia)顎(e)須觸(chu)到蚜(ya)(ya)(ya)(ya)蟲(chong)(chong)(chong)(chong)(chong)時,能迅速地用(yong)上(shang)顎(e)咬(yao)住,將(jiang)(jiang)(jiang)蚜(ya)(ya)(ya)(ya)蟲(chong)(chong)(chong)(chong)(chong)吞食。如(ru)果下(xia)顎(e)須沒有觸(chu)到,即使(shi)蚜(ya)(ya)(ya)(ya)蟲(chong)(chong)(chong)(chong)(chong)就(jiu)在它的(de)(de)眼(yan)前,似乎也不能發(fa)現(xian)。七(qi)(qi)星(xing)(xing)瓢蟲(chong)(chong)(chong)(chong)(chong)成(cheng)蟲(chong)(chong)(chong)(chong)(chong)和(he)幼(you)蟲(chong)(chong)(chong)(chong)(chong)雖都(dou)取(qu)(qu)食蚜(ya)(ya)(ya)(ya)蟲(chong)(chong)(chong)(chong)(chong),但(dan)因蟲(chong)(chong)(chong)(chong)(chong)態(tai)不同,口(kou)(kou)器(qi)結構不同,取(qu)(qu)食方法也有差別。成(cheng)蟲(chong)(chong)(chong)(chong)(chong)取(qu)(qu)食時,通常(chang)將(jiang)(jiang)(jiang)蚜(ya)(ya)(ya)(ya)蟲(chong)(chong)(chong)(chong)(chong)咬(yao)住,經過口(kou)(kou)器(qi)的(de)(de)簡單咀嚼(jiao)后(hou),將(jiang)(jiang)(jiang)蚜(ya)(ya)(ya)(ya)蟲(chong)(chong)(chong)(chong)(chong)軀體、附(fu)肢等完全吞下(xia)。大(da)齡(ling)幼(you)蟲(chong)(chong)(chong)(chong)(chong)取(qu)(qu)食基本上(shang)和(he)成(cheng)蟲(chong)(chong)(chong)(chong)(chong)一(yi)(yi)樣。但(dan)初齡(ling)幼(you)蟲(chong)(chong)(chong)(chong)(chong)因口(kou)(kou)器(qi)小,吞食力差,取(qu)(qu)食時常(chang)在蚜(ya)(ya)(ya)(ya)蟲(chong)(chong)(chong)(chong)(chong)體上(shang)咬(yao)一(yi)(yi)個孔,吸食汁液(ye),最后(hou)留下(xia)蚜(ya)(ya)(ya)(ya)體殘殼。一(yi)(yi)頭七(qi)(qi)星(xing)(xing)瓢蟲(chong)(chong)(chong)(chong)(chong)的(de)(de)成(cheng)蟲(chong)(chong)(chong)(chong)(chong),平均一(yi)(yi)天吃(chi)棉蚜(ya)(ya)(ya)(ya)100-120頭,吃(chi)菜蚜(ya)(ya)(ya)(ya)147頭,吃(chi)杏蚜(ya)(ya)(ya)(ya)59頭。幼(you)蟲(chong)(chong)(chong)(chong)(chong)食蚜(ya)(ya)(ya)(ya)量(liang)則(ze)因齡(ling)期的(de)(de)大(da)小而不同,齡(ling)期小吃(chi)的(de)(de)少(shao),齡(ling)期大(da)吃(chi)的(de)(de)多。
七(qi)星(xing)瓢蟲有吃(chi)卵(luan)(luan)和(he)互相(xiang)捕食的(de)習性。在(zai)食物不足的(de)情況下(xia),七(qi)星(xing)瓢蟲成蟲很容(rong)易吃(chi)掉(diao)(diao)已產(chan)下(xia)的(de)卵(luan)(luan)塊(kuai)(kuai)。即使有充(chong)足的(de)蚜蟲,它們也(ye)喜歡吃(chi)卵(luan)(luan);幼(you)蟲則常(chang)(chang)互相(xiang)捕食。同(tong)一卵(luan)(luan)塊(kuai)(kuai)早孵(fu)出的(de)個體,常(chang)(chang)吃(chi)掉(diao)(diao)尚未(wei)孵(fu)化的(de)卵(luan)(luan)粒(li)。大齡幼(you)蟲常(chang)(chang)吃(chi)掉(diao)(diao)小齡幼(you)蟲。蛹(yong)也(ye)常(chang)(chang)被成蟲和(he)大齡幼(you)蟲吃(chi)掉(diao)(diao)。
七(qi)星(xing)瓢蟲(chong)(chong)(chong)雖然主要(yao)是吃(chi)蚜蟲(chong)(chong)(chong),但并不(bu)僅(jin)僅(jin)限于(yu)以蚜蟲(chong)(chong)(chong)為食(shi)。中(zhong)國北(bei)京的(de)金山腳下,在秋天蒿(hao)草和(he)荊(jing)條上并沒(mei)有蚜蟲(chong)(chong)(chong),七(qi)星(xing)瓢蟲(chong)(chong)(chong)成蟲(chong)(chong)(chong)卻群集其上,數量很多(duo)。經過仔細觀察和(he)消化道(dao)解削(xue)并在顯微鏡下檢查,發現(xian)七(qi)星(xing)瓢蟲(chong)(chong)(chong)在早(zao)春(chun)不(bu)僅(jin)吃(chi)蚜蟲(chong)(chong)(chong),還取食(shi)小土粒、真(zhen)菌孢子和(he)一些小型昆(kun)蟲(chong)(chong)(chong)。秋天,七(qi)星(xing)瓢蟲(chong)(chong)(chong)則常常取食(shi)植(zhi)物的(de)花粉。
七(qi)星瓢蟲(chong)(chong)一(yi)生經(jing)過卵、幼(you)(you)(you)(you)蟲(chong)(chong)、蛹、成蟲(chong)(chong)等四個(ge)發(fa)(fa)育(yu)階段。七(qi)星瓢蟲(chong)(chong)各(ge)蟲(chong)(chong)態的(de)(de)發(fa)(fa)育(yu)歷期(qi)(qi),主要受食(shi)(shi)(shi)物和溫(wen)度(du)的(de)(de)影(ying)響。在適宜(yi)的(de)(de)食(shi)(shi)(shi)物條(tiao)件下,溫(wen)度(du)不(bu)同(tong),發(fa)(fa)育(yu)的(de)(de)速(su)率也不(bu)相(xiang)同(tong)。幼(you)(you)(you)(you)蟲(chong)(chong)期(qi)(qi)在15℃條(tiao)件下,長(chang)達44.1天,而(er)在24-26℃時(shi)(shi)只有(you)8-9.4天。高于30℃發(fa)(fa)育(yu)速(su)率又逐(zhu)漸降低(di),33℃時(shi)(shi)幼(you)(you)(you)(you)蟲(chong)(chong)期(qi)(qi)又延長(chang)到16.2天。溫(wen)度(du)不(bu)適宜(yi)時(shi)(shi)發(fa)(fa)育(yu)緩慢的(de)(de)原因,除直接(jie)受溫(wen)度(du)影(ying)響外,取(qu)食(shi)(shi)(shi)速(su)率低(di)也有(you)關系。一(yi)頭四齡幼(you)(you)(you)(you)蟲(chong)(chong)在25℃左右時(shi)(shi),每(mei)天取(qu)食(shi)(shi)(shi)一(yi)百多頭蚜蟲(chong)(chong),而(er)在15℃時(shi)(shi),僅取(qu)食(shi)(shi)(shi)十幾(ji)頭。
七(qi)(qi)星瓢蟲(chong)(chong)(chong)以(yi)成蟲(chong)(chong)(chong)越(yue)冬(dong),多選擇(ze)較干燥(zao)、溫(wen)暖(nuan)的枯枝(zhi)落葉下、雜草(cao)基部近(jin)地(di)面的土塊(kuai)下、土縫(feng)中、樹皮裂縫(feng)處潛伏,蟄伏越(yue)冬(dong)后(hou),若遇(yu)溫(wen)度回(hui)暖(nuan),又爬出(chu)越(yue)冬(dong)場所(suo)活動(dong)。出(chu)蟄后(hou)的七(qi)(qi)星瓢蟲(chong)(chong)(chong)迅速在(zai)林木、雜草(cao)和(he)(he)作(zuo)物之間(jian)活動(dong),特別(bie)是帶(dai)蚜蟲(chong)(chong)(chong)的作(zuo)物與開花果木上。七(qi)(qi)星瓢蟲(chong)(chong)(chong)是遷飛性昆蟲(chong)(chong)(chong),成蟲(chong)(chong)(chong)和(he)(he)幼蟲(chong)(chong)(chong)的覓食行為(wei)屬(shu)于廣(guang)域搜索與區域集中搜索行為(wei)的轉(zhuan)換。
七星瓢蟲(chong)有著驚人(ren)(ren)的(de)(de)(de)避(bi)(bi)敵(di)本領(ling)。只要有天敵(di)來擾或受到(dao)外界突然(ran)的(de)(de)(de)刺激,它就會發(fa)(fa)生一(yi)種(zhong)叫(jiao)做“神(shen)經休克”現象,有點像失去知(zhi)覺(jue)似的(de)(de)(de)一(yi)動不動。“休克”過后,受到(dao)刺激的(de)(de)(de)神(shen)經系統恢復正常,它又清(qing)醒過來,開始爬行。這種(zhong)“死去活來”的(de)(de)(de)舉止,人(ren)(ren)們稱它“假死”。如果用手去捏它,它就會使出(chu)第二招避(bi)(bi)敵(di)本領(ling),在它6條(tiao)足上的(de)(de)(de)各關節中間,滲出(chu)一(yi)種(zhong)黃(huang)色(se)汁液來,這些汁液散(san)發(fa)(fa)出(chu)來的(de)(de)(de)辣(la)臭(chou)味,可使人(ren)(ren)聞(wen)之感到(dao)膩煩(fan),就連鳥類聞(wen)到(dao)這種(zhong)怪味,也“退避(bi)(bi)三舍”。
七(qi)星(xing)瓢(piao)蟲在不(bu)同(tong)季節的(de)(de)活動場所不(bu)一樣。冬(dong)天,七(qi)星(xing)瓢(piao)蟲在小(xiao)麥和(he)(he)油(you)菜的(de)(de)根莖(jing)間越冬(dong),也有的(de)(de)在向(xiang)陽的(de)(de)土塊、土縫(feng)中過(guo)冬(dong)。春天,一旦氣(qi)溫升到10℃以上(shang)(shang),越冬(dong)的(de)(de)七(qi)星(xing)瓢(piao)蟲就(jiu)蘇醒過(guo)來(lai),開始(shi)活動,在麥類和(he)(he)油(you)菜植物株上(shang)(shang)能找(zhao)(zhao)到它。夏天,隨著氣(qi)溫升高和(he)(he)食物增多,七(qi)星(xing)瓢(piao)蟲大(da)量繁殖,凡是有蚜蟲和(he)(he)蚧蟲寄(ji)生(sheng)的(de)(de)植物,如棉花、柳樹、槐樹、榆樹、豆類等(deng)植株上(shang)(shang),都能找(zhao)(zhao)到七(qi)星(xing)瓢(piao)蟲,有時甚至(zhi)出現大(da)批七(qi)星(xing)瓢(piao)蟲聚(ju)集的(de)(de)景象。秋天,田間七(qi)星(xing)瓢(piao)蟲的(de)(de)數量減(jian)少,它常在玉米、蘿卜和(he)(he)白(bai)菜等(deng)處(chu)產卵,這時候(hou),早晚的(de)(de)氣(qi)溫較低,七(qi)星(xing)瓢(piao)蟲往(wang)往(wang)隱蔽起來(lai),不(bu)易發現,需(xu)在上(shang)(shang)午7點鐘以后至(zhi)太陽下山(shan)之前(qian)采集。
越(yue)冬的七(qi)(qi)星瓢蟲不(bu)食(shi)不(bu)動(dong),只要找到(dao),捕(bu)捉很方便(bian),用(yong)手就(jiu)能捉住。其他季節的七(qi)(qi)星瓢蟲善爬能飛(fei),可以(yi)利用(yong)它(ta)假(jia)死習性(xing),用(yong)塑(su)料袋(dai)迅速套住棲(qi)息著(zhu)(zhu)七(qi)(qi)星瓢蟲的枝(zhi)條,抖動(dong)一下,七(qi)(qi)星瓢蟲立即(ji)掉(diao)落在袋(dai)里,接(jie)著(zhu)(zhu),把枝(zhi)條抽出,扎緊口(kou)袋(dai),就(jiu)可以(yi)帶回實驗室。
人(ren)(ren)(ren)工飼養七(qi)星瓢蟲(chong),首先要解(jie)決飼料問題。可(ke)(ke)以(yi)到野外采集天然(ran)飼料蚜(ya)(ya)蟲(chong),但(dan)這(zhe)(zhe)種方法費工多,有時(shi)還(huan)不(bu)易采到。所以(yi)用人(ren)(ren)(ren)工培養大量蚜(ya)(ya)蟲(chong),滿(man)足七(qi)星瓢蟲(chong)食用。可(ke)(ke)用蠶豆苗人(ren)(ren)(ren)工培養蚜(ya)(ya)蟲(chong)。當(dang)分栽的蠶豆苗長出3-4厘(li)米高時(shi),把(ba)野外采集的少量蚜(ya)(ya)蟲(chong)放在(zai)豆苗上,在(zai)室溫20-30℃、相對(dui)濕(shi)度(du)60-70%的條件下(xia)培養10-15天,蚜(ya)(ya)蟲(chong)就(jiu)能大量繁殖,這(zhe)(zhe)時(shi)就(jiu)可(ke)(ke)用蚜(ya)(ya)蟲(chong)作七(qi)星瓢蟲(chong)的飼料。
將(jiang)蛹(yong)或(huo)成(cheng)(cheng)蟲(chong)(chong)放入(ru)成(cheng)(cheng)蟲(chong)(chong)飼養籠(long)(long)(long)內(nei),每籠(long)(long)(long)放雌蟲(chong)(chong)500-750頭,并搭配1/4的(de)雄蟲(chong)(chong)。成(cheng)(cheng)蟲(chong)(chong)喂人工飼料或(huo)蚜蟲(chong)(chong),每天喂飼料和加水(shui)。新(xin)羽化(hua)的(de)成(cheng)(cheng)蟲(chong)(chong),經過幾天的(de)取食,逐(zhu)步達到性成(cheng)(cheng)熟(shu),便交尾產(chan)卵(luan)(luan)。產(chan)卵(luan)(luan)時(shi)間多在(zai)晚上(shang)7-9點鐘。卵(luan)(luan)產(chan)在(zai)籠(long)(long)(long)頂和內(nei)側的(de)紙上(shang),收卵(luan)(luan)時(shi),將(jiang)籠(long)(long)(long)內(nei)的(de)紙取出,換(huan)上(shang)新(xin)鮮的(de)紙就(jiu)成(cheng)(cheng)了。收卵(luan)(luan)每天1-2次(ci),同時(shi)換(huan)飼料和水(shui)。收卵(luan)(luan)時(shi)先準備一(yi)批空飼養籠(long)(long)(long),籠(long)(long)(long)底(di)(di)打開,頂面向光,然后將(jiang)有蟲(chong)(chong)的(de)籠(long)(long)(long)底(di)(di)面紗(sha)布拆(chai)開,籠(long)(long)(long)底(di)(di)對準籠(long)(long)(long)底(di)(di),成(cheng)(cheng)蟲(chong)(chong)馬(ma)上(shang)向有光的(de)方向集中(zhong),進(jin)入(ru)新(xin)的(de)籠(long)(long)(long)內(nei)。
成(cheng)蟲(chong)飼養時,如(ru)食料不足,就不產(chan)卵。成(cheng)蟲(chong)在(zai)黑暗條件下(xia)活躍(yue),晚(wan)上可適當加(jia)光照,減少成(cheng)蟲(chong)活動,避(bi)免相(xiang)互(hu)碰傷。
七(qi)星(xing)瓢蟲(chong)大(da)量繁殖后,可(ke)以(yi)(yi)放(fang)(fang)(fang)(fang)(fang)(fang)(fang)到田(tian)間(jian),幫助人類消滅蚜蟲(chong)和蚧(jie)蟲(chong)。如棉田(tian)出現大(da)量蚜蟲(chong)危(wei)害,這時(shi)可(ke)以(yi)(yi)把七(qi)星(xing)瓢蟲(chong)散放(fang)(fang)(fang)(fang)(fang)(fang)(fang)到棉田(tian)里,它(ta)就能將(jiang)蚜蟲(chong)吃(chi)掉。散發時(shi),在棉田(tian)邊走邊放(fang)(fang)(fang)(fang)(fang)(fang)(fang)七(qi)星(xing)瓢蟲(chong),走幾步放(fang)(fang)(fang)(fang)(fang)(fang)(fang)幾只,以(yi)(yi)求散放(fang)(fang)(fang)(fang)(fang)(fang)(fang)均勻:①掌握好(hao)散放(fang)(fang)(fang)(fang)(fang)(fang)(fang)時(shi)間(jian),以(yi)(yi)傍(bang)晚時(shi)散放(fang)(fang)(fang)(fang)(fang)(fang)(fang)為宜。因為傍(bang)晚氣溫較低,光線較暗,七(qi)星(xing)瓢蟲(chong)活動性(xing)較弱,不(bu)易遷飛(fei);②采用成蟲(chong)和幼蟲(chong)混(hun)放(fang)(fang)(fang)(fang)(fang)(fang)(fang)。因為幼蟲(chong)沒有遷飛(fei)能力,不(bu)會(hui)逃逸,而它(ta)也有吃(chi)蚜蟲(chong)的(de)本領;③散發前(qian)一天停止喂食,再進(jin)行散放(fang)(fang)(fang)(fang)(fang)(fang)(fang),可(ke)以(yi)(yi)降低七(qi)星(xing)瓢蟲(chong)遷飛(fei)活動能力;④散放(fang)(fang)(fang)(fang)(fang)(fang)(fang)后兩天內,不(bu)進(jin)行中(zhong)耕和其他田(tian)間(jian)管(guan)理,以(yi)(yi)免使七(qi)星(xing)瓢蟲(chong)受(shou)驚遷逃。
七星瓢蟲(chong)卵通常成塊地產在莖(jing)葉(xie)或土塊上(shang)。卵粒梭形,豎(shu)立,整齊地排(pai)列(lie)成塊。每個卵塊一般30粒左右(you)。最多可達百余(yu)粒,少的(de)則僅有幾(ji)粒。剛產下的(de)卵淡黃色(se)(se),后逐漸(jian)變為杏(xing)黃色(se)(se)。將孵化時,呈黑渴色(se)(se)。
新(xin)羽化的(de)七星瓢(piao)蟲(chong)(chong)(chong)成(cheng)蟲(chong)(chong)(chong),待體(ti)軀和翅鞘硬化后(hou)(hou),便開(kai)始(shi)活動(dong)取(qu)(qu)食(shi)(shi)(shi)(shi),3-4天(tian)后(hou)(hou)交尾(wei)。七星瓢(piao)蟲(chong)(chong)(chong)有多次交尾(wei)習性,但(dan)經(jing)一次交尾(wei),雌(ci)蟲(chong)(chong)(chong)所(suo)產(chan)的(de)卵(luan)(luan)就(jiu)都能(neng)孵化。秋季越冬代成(cheng)蟲(chong)(chong)(chong)交尾(wei)后(hou)(hou),雖活動(dong)取(qu)(qu)食(shi)(shi)(shi)(shi),但(dan)卵(luan)(luan)巢并(bing)不發育,翌春活動(dong)取(qu)(qu)食(shi)(shi)(shi)(shi)后(hou)(hou)才開(kai)始(shi)產(chan)卵(luan)(luan)。非越冬代成(cheng)蟲(chong)(chong)(chong)交尾(wei)3-5天(tian)后(hou)(hou),便開(kai)始(shi)產(chan)卵(luan)(luan)。產(chan)卵(luan)(luan)開(kai)始(shi)以(yi)(yi)后(hou)(hou),幾(ji)天(tian)內就(jiu)達到了(le)高峰,產(chan)卵(luan)(luan)盛期持續一個月左(zuo)右。在盛期的(de)33天(tian)里,產(chan)下了(le)全部卵(luan)(luan)粒的(de)95%以(yi)(yi)上。產(chan)卵(luan)(luan)盛期,一頭雌(ci)蟲(chong)(chong)(chong)一天(tian)可(ke)產(chan)好幾(ji)個卵(luan)(luan)塊。七星瓢(piao)蟲(chong)(chong)(chong)因取(qu)(qu)食(shi)(shi)(shi)(shi)的(de)蚜蟲(chong)(chong)(chong)種類(lei)不同,產(chan)卵(luan)(luan)量大(da)(da)小(xiao)也不同。取(qu)(qu)食(shi)(shi)(shi)(shi)它喜歡吃的(de)蚜蟲(chong)(chong)(chong)時,產(chan)卵(luan)(luan)量就(jiu)大(da)(da),取(qu)(qu)食(shi)(shi)(shi)(shi)不害歡吃的(de)蚜蟲(chong)(chong)(chong)時,產(chan)卵(luan)(luan)量就(jiu)小(xiao)。
七星瓢蟲卵(luan)期長短和溫度有關系,當16-17℃時,卵(luan)期8天(tian),24-26℃時,卵(luan)期僅2-3天(tian)。七星瓢蟲成(cheng)蟲壽(shou)(shou)命因世代不同而有較大(da)差異。越(yue)冬代成(cheng)蟲壽(shou)(shou)命一般都較長,可達(da)8-10個(ge)(ge)月,非(fei)越(yue)冬代成(cheng)蟲一般可活2-3個(ge)(ge)月。
七(qi)星瓢蟲(chong)(chong)的(de)(de)(de)生殖滯(zhi)(zhi)(zhi)育突出地表現(xian)于2個方面:①種群(qun)中產(chan)卵(luan)(luan)雌(ci)蟲(chong)(chong)所(suo)占的(de)(de)(de)比例,簡稱為(wei)產(chan)卵(luan)(luan)率,無滯(zhi)(zhi)(zhi)育時達100%;如(ru)越冬后蚜蟲(chong)(chong)充足時便是如(ru)此(ci)。而(er)其第二(er)代則因有(you)生殖滯(zhi)(zhi)(zhi)育,產(chan)卵(luan)(luan)率下降。②成蟲(chong)(chong)羽化后產(chan)卵(luan)(luan)前期延長的(de)(de)(de)程度,這(zhe)主(zhu)要由卵(luan)(luan)巢發育緩慢或暫時停頓所(suo)造成。顯示出這(zhe)種差異的(de)(de)(de)是雌(ci)蟲(chong)(chong)。而(er)雄蟲(chong)(chong)在滯(zhi)(zhi)(zhi)育期間其行為(wei)、趨性和生殖附腺的(de)(de)(de)分泌活動雖與生殖期有(you)所(suo)不(bu)同(tong),但仍(reng)可(ke)交尾,睪丸中有(you)成熟精(jing)子。雌(ci)蟲(chong)(chong)滯(zhi)(zhi)(zhi)育時卵(luan)(luan)巢管停止于原(yuan)卵(luan)(luan)區階段,濾泡不(bu)進行發育。這(zhe)時咽側(ce)體及其細(xi)胞體積(ji)均小,無合(he)成保(bao)幼激素的(de)(de)(de)活性。體內積(ji)累(lei)較多的(de)(de)(de)營養物質,脂肪體雖很發達,但不(bu)合(he)成卵(luan)(luan)黃原(yuan)蛋(dan)白。
早春田間采(cai)集的(de)(de)越冬代七(qi)星瓢(piao)蟲(chong),因(yin)其(qi)發育階段不(bu)同,一般采(cai)回飼養(yang)1-7天后即開始產卵(luan)(luan)(luan)(luan)(luan)(luan)。瓢(piao)蟲(chong)產卵(luan)(luan)(luan)(luan)(luan)(luan)沒有(you)(you)固(gu)定的(de)(de)時(shi)(shi)間,產卵(luan)(luan)(luan)(luan)(luan)(luan)的(de)(de)地點(dian)也沒有(you)(you)嚴格的(de)(de)選擇性,在(zai)(zai)(zai)盒(he)(he)壁(bi)及植物(wu)上(shang)都可(ke)產卵(luan)(luan)(luan)(luan)(luan)(luan),為(wei)了集卵(luan)(luan)(luan)(luan)(luan)(luan)的(de)(de)方便,可(ke)以裁一長22厘(li)米(mi)、寬(kuan)5厘(li)米(mi)的(de)(de)薄紙(zhi)(zhi),卷成(cheng)紙(zhi)(zhi)筒,襯(chen)在(zai)(zai)(zai)紙(zhi)(zhi)盒(he)(he)內(nei)(nei)或玻璃器內(nei)(nei),使(shi)其(qi)盡量(liang)緊貼在(zai)(zai)(zai)紙(zhi)(zhi)盒(he)(he)內(nei)(nei)壁(bi),這樣卵(luan)(luan)(luan)(luan)(luan)(luan)多產在(zai)(zai)(zai)襯(chen)紙(zhi)(zhi)上(shang)。采(cai)卵(luan)(luan)(luan)(luan)(luan)(luan)時(shi)(shi),可(ke)將(jiang)(jiang)襯(chen)紙(zhi)(zhi)取出,將(jiang)(jiang)有(you)(you)卵(luan)(luan)(luan)(luan)(luan)(luan)粒部(bu)(bu)位(wei)的(de)(de)紙(zhi)(zhi)剪(jian)下(xia),放另外的(de)(de)空紙(zhi)(zhi)盒(he)(he)中(zhong)(zhong),然(ran)后再用(yong)(yong)(yong)紙(zhi)(zhi)片補好襯(chen)紙(zhi)(zhi),仍(reng)放盒(he)(he)內(nei)(nei)再用(yong)(yong)(yong)。取卵(luan)(luan)(luan)(luan)(luan)(luan)時(shi)(shi)應(ying)仔細(xi)檢查盒(he)(he)內(nei)(nei)植物(wu)上(shang)有(you)(you)無(wu)卵(luan)(luan)(luan)(luan)(luan)(luan)粒,特(te)別在(zai)(zai)(zai)氣候干燥時(shi)(shi),植物(wu)常(chang)常(chang)干縮,卵(luan)(luan)(luan)(luan)(luan)(luan)粒常(chang)隱藏其(qi)中(zhong)(zhong),如發現卵(luan)(luan)(luan)(luan)(luan)(luan)粒,應(ying)將(jiang)(jiang)帶有(you)(you)卵(luan)(luan)(luan)(luan)(luan)(luan)粒的(de)(de)部(bu)(bu)位(wei)剪(jian)下(xia)。如果用(yong)(yong)(yong)瓶養(yang),瓢(piao)蟲(chong)卵(luan)(luan)(luan)(luan)(luan)(luan)產在(zai)(zai)(zai)瓶壁(bi)上(shang),取卵(luan)(luan)(luan)(luan)(luan)(luan)時(shi)(shi)可(ke)用(yong)(yong)(yong)毛(mao)(mao)筆沾少許清水,將(jiang)(jiang)卵(luan)(luan)(luan)(luan)(luan)(luan)濕潤(run),經數(shu)秒鐘(zhong)后,再用(yong)(yong)(yong)毛(mao)(mao)筆尖(jian)輕輕將(jiang)(jiang)卵(luan)(luan)(luan)(luan)(luan)(luan)撥下(xia),放在(zai)(zai)(zai)涂(tu)有(you)(you)少許稀漿糊的(de)(de)紙(zhi)(zhi)上(shang),只要卵(luan)(luan)(luan)(luan)(luan)(luan)粒保持完整(zheng),仍(reng)然(ran)正常(chang)孵化。但這樣取卵(luan)(luan)(luan)(luan)(luan)(luan),很(hen)難保證全(quan)部(bu)(bu)卵(luan)(luan)(luan)(luan)(luan)(luan)粒完整(zheng)無(wu)損,且操作費時(shi)(shi),因(yin)此(ci)在(zai)(zai)(zai)大規模飼養(yang)瓢(piao)蟲(chong)寸,仍(reng)以紙(zhi)(zhi)盒(he)(he)為(wei)宜。
瓢蟲成(cheng)蟲有取食卵(luan)(luan)粒的習性,產卵(luan)(luan)后,應(ying)及時(shi)將卵(luan)(luan)粒取走。每日取卵(luan)(luan)的時(shi)間,可結合(he)兩(liang)次(ci)喂食同時(shi)進行,邊換飼(si)料、邊取卵(luan)(luan)。產卵(luan)(luan)高峰期,最好能每日取卵(luan)(luan)三次(ci)。
七星瓢蟲(chong)的卵(luan)是一粒(li)粒(li)豎立(li)成排,形(xing)成整齊的卵(luan)塊,由飼養盒(he)中(zhong)取(qu)出(chu)以(yi)(yi)后(hou)堆(dui)放在一起,很(hen)容易彼此摩擦,影響孵化(hua)率。七星瓢蟲(chong)的卵(luan)在20℃時,只需(xu)5-6天(tian)即可(ke)孵化(hua)。25℃時只需(xu)3天(tian)即可(ke)孵化(hua)。如果長時間堆(dui)放在一起,不僅降低(di)孵化(hua)率,而(er)且幼蟲(chong)孵化(hua)以(yi)(yi)后(hou),也不便于收集飼養。因此,每次取(qu)出(chu)卵(luan)粒(li)以(yi)(yi)后(hou),應(ying)及時進行處(chu)理。可(ke)通過(guo)制取(qu)卵(luan)卡解決以(yi)(yi)上問題。
七星瓢(piao)蟲的(de)(de)(de)(de)(de)產卵(luan)(luan)(luan)期(qi)可(ke)(ke)長(chang)達20-30天(tian),產卵(luan)(luan)(luan)的(de)(de)(de)(de)(de)高(gao)峰期(qi)亦(yi)有7-10天(tian),因此(ci),收集的(de)(de)(de)(de)(de)卵(luan)(luan)(luan)塊必須立即進(jin)行低(di)(di)溫(wen)保(bao)存(cun)(cun),以防(fang)止(zhi)逐日(ri)孵化(hua)(hua)不(bu)便(bian)集中(zhong)使用。加之自然氣(qi)候的(de)(de)(de)(de)(de)變化(hua)(hua)或人工飼養瓢(piao)蟲的(de)(de)(de)(de)(de)條件改(gai)變,都會(hui)造成瓢(piao)蟲的(de)(de)(de)(de)(de)產卵(luan)(luan)(luan)高(gao)峰期(qi)、卵(luan)(luan)(luan)的(de)(de)(de)(de)(de)孵化(hua)(hua)期(qi)與田間(jian)(jian)蚜(ya)蟲發生的(de)(de)(de)(de)(de)時間(jian)(jian)不(bu)相配合,也常需要對卵(luan)(luan)(luan)做低(di)(di)溫(wen)保(bao)存(cun)(cun)。保(bao)存(cun)(cun)的(de)(de)(de)(de)(de)時間(jian)(jian)長(chang)短(duan),溫(wen)度(du)高(gao)低(di)(di)都有一定的(de)(de)(de)(de)(de)限度(du)。在(zai)0℃時保(bao)存(cun)(cun)3天(tian),其(qi)孵化(hua)(hua)率(lv)(lv)仍(reng)能達到(dao)(dao)70%以上。超(chao)過(guo)3天(tian),孵化(hua)(hua)率(lv)(lv)大為(wei)(wei)降(jiang)低(di)(di)。如(ru)在(zai)4℃時,可(ke)(ke)保(bao)存(cun)(cun)7天(tian),孵化(hua)(hua)率(lv)(lv)在(zai)70%以上。在(zai)11-13℃之間(jian)(jian),卵(luan)(luan)(luan)可(ke)(ke)保(bao)存(cun)(cun)20天(tian),其(qi)孵化(hua)(hua)率(lv)(lv)仍(reng)然達到(dao)(dao)80%左(zuo)右。實驗表明,七星瓢(piao)蟲發育(yu)起點(dian)(dian)溫(wen)度(du)為(wei)(wei)10℃左(zuo)右,低(di)(di)于這(zhe)個溫(wen)度(du),瓢(piao)蟲卵(luan)(luan)(luan)雖可(ke)(ke)短(duan)時間(jian)(jian)保(bao)存(cun)(cun),但其(qi)成活(huo)率(lv)(lv)不(bu)高(gao)。如(ru)保(bao)存(cun)(cun)在(zai)發育(yu)起點(dian)(dian)溫(wen)度(du)之上,保(bao)存(cun)(cun)天(tian)數較長(chang),孵化(hua)(hua)率(lv)(lv)亦(yi)高(gao)。因此(ci),卵(luan)(luan)(luan)的(de)(de)(de)(de)(de)保(bao)存(cun)(cun)溫(wen)度(du)以10-12℃為(wei)(wei)宜(yi)。
卵(luan)的(de)(de)孵(fu)(fu)(fu)化(hua)(hua)要求(qiu)有一定的(de)(de)溫濕(shi)(shi)(shi)(shi)(shi)度(du)(du)(du)條(tiao)(tiao)件(jian)(jian)。在發(fa)育(yu)起點溫度(du)(du)(du)以(yi)(yi)(yi)上,卵(luan)雖(sui)然可以(yi)(yi)(yi)孵(fu)(fu)(fu)化(hua)(hua),但(dan)其最適(shi)宜的(de)(de)溫度(du)(du)(du)是20-25℃,相(xiang)對(dui)濕(shi)(shi)(shi)(shi)(shi)度(du)(du)(du)70-80%。因(yin)此(ci)在卵(luan)需要孵(fu)(fu)(fu)化(hua)(hua)時(shi)(shi)(shi),應由貯存處取回,放(fang)于室(shi)溫中進行(xing)。一般在棉(mian)蚜(ya)開始遷飛棉(mian)田時(shi)(shi)(shi),日平均(jun)溫度(du)(du)(du)皆在15℃左(zuo)右,均(jun)能滿(man)足卵(luan)的(de)(de)孵(fu)(fu)(fu)化(hua)(hua)溫度(du)(du)(du)條(tiao)(tiao)件(jian)(jian),孵(fu)(fu)(fu)化(hua)(hua)的(de)(de)關鍵條(tiao)(tiao)件(jian)(jian)就(jiu)在于濕(shi)(shi)(shi)(shi)(shi)度(du)(du)(du)。如濕(shi)(shi)(shi)(shi)(shi)度(du)(du)(du)在80%以(yi)(yi)(yi)上,小幼蟲很容(rong)易由卵(luan)殼內孵(fu)(fu)(fu)出(chu)(chu),但(dan)在干(gan)燥低濕(shi)(shi)(shi)(shi)(shi)的(de)(de)條(tiao)(tiao)件(jian)(jian)下,小幼蟲常在卵(luan)口處掙(zheng)扎,不(bu)(bu)易脫出(chu)(chu)。嚴重時(shi)(shi)(shi),甚至不(bu)(bu)孵(fu)(fu)(fu)化(hua)(hua)。因(yin)此(ci)大(da)量的(de)(de)卵(luan)需要孵(fu)(fu)(fu)化(hua)(hua)時(shi)(shi)(shi),應創造高濕(shi)(shi)(shi)(shi)(shi)條(tiao)(tiao)件(jian)(jian)。孵(fu)(fu)(fu)化(hua)(hua)時(shi)(shi)(shi)可在孵(fu)(fu)(fu)化(hua)(hua)室(shi)內地(di)面潑(po)水(shui),掛濕(shi)(shi)(shi)(shi)(shi)布等,增加室(shi)內濕(shi)(shi)(shi)(shi)(shi)度(du)(du)(du);亦可同時(shi)(shi)(shi)在盛放(fang)卵(luan)卡(ka)的(de)(de)容(rong)器(qi)內放(fang)濕(shi)(shi)(shi)(shi)(shi)棉(mian)球(qiu),容(rong)器(qi)頂部(bu)再蓋以(yi)(yi)(yi)濕(shi)(shi)(shi)(shi)(shi)布,增加卵(luan)卡(ka)周(zhou)圍水(shui)分的(de)(de)蒸(zheng)發(fa)條(tiao)(tiao)件(jian)(jian),經(jing)過這樣處理(li)以(yi)(yi)(yi)后,卵(luan)的(de)(de)孵(fu)(fu)(fu)化(hua)(hua)時(shi)(shi)(shi)間較快,孵(fu)(fu)(fu)出(chu)(chu)后小幼蟲生命力(li)較強。
卵孵(fu)(fu)化時,應加強檢查(cha)與管理,每日(ri)至(zhi)少檢查(cha)4次(ci),發現幼蟲孵(fu)(fu)出(chu)后,應及(ji)時取出(chu)。在(zai)卵的(de)孵(fu)(fu)化高峰時,應3-4小時檢查(cha)一(yi)次(ci),并且要求日(ri)夜(ye)有人看(kan)管。