寄生(sheng)蜂(Parasitoid wasp),指膜翅目細腰亞目中金小蜂科、姬蜂科、小蜂科等靠寄生(sheng)生(sheng)活的(de)多(duo)種昆蟲。它們的(de)寄生(sheng)方式(shi)很多(duo),被(bei)寄生(sheng)對象從卵到成蟲的(de)各個階段,都(dou)可(ke)能被(bei)寄生(sheng)。所(suo)謂寄生(sheng)蜂,就是(shi)從植食性(xing)蜂類(lei)進化到筑巢性(xing)期間的(de)一(yi)群(qun)肉食性(xing)蜂類(lei)。與寄生(sheng)蟲一(yi)樣。
分成外寄(ji)生和內(nei)寄(ji)生兩大類(lei)。前者是(shi)(shi)指把卵產在(zai)寄(ji)主體(ti)表(biao),讓(rang)(rang)孵化(hua)的幼(you)(you)蟲從(cong)體(ti)表(biao)取食(shi)寄(ji)主身體(ti);后(hou)者是(shi)(shi)把卵產在(zai)寄(ji)主體(ti)內(nei),讓(rang)(rang)孵化(hua)的幼(you)(you)蟲取食(shi)害蟲體(ti)內(nei)的組織。內(nei)寄(ji)生形式(shi)者,被認為較為進化(hua)。
外(wai)寄(ji)(ji)(ji)生者在產(chan)卵(luan)前(qian),必須克服一件事,就(jiu)是得讓寄(ji)(ji)(ji)主(zhu)無法(fa)動彈,否則卵(luan)會被寄(ji)(ji)(ji)主(zhu)壓(ya)壞(huai),甚至被寄(ji)(ji)(ji)主(zhu)咬死。因(yin)此,外(wai)寄(ji)(ji)(ji)生蜂會先(xian)用產(chan)卵(luan)管(guan)蜇(zhe)刺寄(ji)(ji)(ji)主(zhu),注射有毒物質麻痹寄(ji)(ji)(ji)主(zhu)。也就(jiu)是說,產(chan)卵(luan)管(guan)除了產(chan)卵(luan)功(gong)能外(wai),兼(jian)具注入(ru)麻醉(zui)液(ye)的(de)功(gong)能。此外(wai),還有一個待(dai)解(jie)決的(de)問(wen)(wen)題,就(jiu)是寄(ji)(ji)(ji)主(zhu)必須有造繭性等(deng)隱(yin)蔽身(shen)體的(de)習性,因(yin)為(wei)寄(ji)(ji)(ji)主(zhu)若(ruo)遭(zao)麻醉(zui),行動變得遲鈍,容易(yi)受(shou)到敵害攻擊(ji)或其他外(wai)在環境的(de)傷害,如果沒有隱(yin)蔽自己的(de)絕(jue)活(huo),體表(biao)的(de)寄(ji)(ji)(ji)生蜂幼蟲(chong)也將會與它同歸于(yu)盡。而采用內(nei)寄(ji)(ji)(ji)生方式的(de)寄(ji)(ji)(ji)生蜂,問(wen)(wen)題就(jiu)沒有那么嚴重。
此外,也有像蜘(zhi)蛛姬蜂這類(lei)具有產卵特技(ji)寄生(sheng)蜂,它(ta)們以(yi)蜘(zhi)蛛網上的(de)蜘(zhi)蛛為寄主。當它(ta)突襲蜘(zhi)蛛時(shi),會先刺蜇蜘(zhi)蛛腳(jiao)(jiao)的(de)基部,利用其(qi)暫時(shi)失去感覺之際,在它(ta)的(de)頭胸部或腹部腹面產下一粒卵,蜘(zhi)蛛后來雖然恢復知(zhi)覺,但由(you)于腳(jiao)(jiao)摳不到卵,只好任由(you)孵化(hua)的(de)姬蜂幼蟲吸血,而終至死亡。
寄(ji)生蜂的種類(lei)很多(duo),分(fen)別寄(ji)生于寄(ji)主的不同發(fa)育階段,常見的有小蜂、姬(ji)蜂、繭(jian)蜂、赤眼蜂、嚙小蜂等(deng)。
姬(ji)蜂(feng)(feng)(feng)是膜(mo)(mo)翅(chi)(chi)(chi)目姬(ji)蜂(feng)(feng)(feng)科(ke)(ke)的(de)(de)(de)一(yi)種寄(ji)生(sheng)(sheng)(sheng)蜂(feng)(feng)(feng),膜(mo)(mo)翅(chi)(chi)(chi)目(Hymenoptera)姬(ji)蜂(feng)(feng)(feng)科(ke)(ke)(Ichneunmonidae,有(you)(you)重要經濟意義的(de)(de)(de)一(yi)個(ge)(ge)大科(ke)(ke))昆蟲(chong)(chong)(chong)(chong)(chong)。分布(bu)很廣(guang),約40,000種。形狀(zhuang)、顏色、大小各異,一(yi)般1.2公(gong)分(約0.5寸(cun))長。北美洲最長的(de)(de)(de)長針姬(ji)蜂(feng)(feng)(feng)屬(shu)達5公(gong)分。許(xu)多(duo)種的(de)(de)(de)腹部細長而彎曲,像黃(huang)蜂(feng)(feng)(feng),區別一(yi)般在(zai)(zai)(zai)于觸角較(jiao)長,節較(jiao)多(duo)。產(chan)卵(luan)器通常(chang)比身(shen)體長。許(xu)多(duo)種的(de)(de)(de)前(qian)翅(chi)(chi)(chi)有(you)(you)一(yi)黑點(dian)。寄(ji)生(sheng)(sheng)(sheng)在(zai)(zai)(zai)蜘蛛以及多(duo)類昆蟲(chong)(chong)(chong)(chong)(chong)上,尤其(qi)是鱗(lin)翅(chi)(chi)(chi)目和其(qi)他膜(mo)(mo)翅(chi)(chi)(chi)目昆蟲(chong)(chong)(chong)(chong)(chong)。由于寄(ji)生(sheng)(sheng)(sheng)在(zai)(zai)(zai)許(xu)多(duo)害(hai)蟲(chong)(chong)(chong)(chong)(chong)上,總的(de)(de)(de)來說(shuo)是益蟲(chong)(chong)(chong)(chong)(chong)。雌蜂(feng)(feng)(feng)在(zai)(zai)(zai)宿(su)主(zhu)的(de)(de)(de)幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong)或蛹(yong)(很少在(zai)(zai)(zai)卵(luan)或成(cheng)(cheng)體)上產(chan)卵(luan)。幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong)取食宿(su)主(zhu)的(de)(de)(de)脂肪(fang)和體液,長成(cheng)(cheng)后(hou)織一(yi)繭。如(ru)果宿(su)主(zhu)生(sheng)(sheng)(sheng)活場所不是隱(yin)蔽(bi)的(de)(de)(de),則通常(chang)寄(ji)生(sheng)(sheng)(sheng)在(zai)(zai)(zai)宿(su)主(zhu)體內(nei);若宿(su)主(zhu)生(sheng)(sheng)(sheng)活在(zai)(zai)(zai)隱(yin)蔽(bi)處(如(ru)樹木(mu)孔道內(nei)),則常(chang)寄(ji)生(sheng)(sheng)(sheng)在(zai)(zai)(zai)宿(su)主(zhu)體姬(ji)蜂(feng)(feng)(feng)外。一(yi)個(ge)(ge)宿(su)主(zhu)上多(duo)數只有(you)(you)一(yi)個(ge)(ge)幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong),但有(you)(you)時(shi)也可(ke)有(you)(you)多(duo)個(ge)(ge)幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong)寄(ji)生(sheng)(sheng)(sheng)。赤(chi)眼(yan)蜂(feng)(feng)(feng)以眼(yan)紅(hong)色而得名,它經常(chang)把(ba)卵(luan)產(chan)在(zai)(zai)(zai)松毛蟲(chong)(chong)(chong)(chong)(chong)、玉米(mi)螟(ming)(ming)、二化螟(ming)(ming)及甘(gan)蔗螟(ming)(ming)的(de)(de)(de)卵(luan)中(zhong)(zhong)(zhong),幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong)就以寄(ji)生(sheng)(sheng)(sheng)卵(luan)中(zhong)(zhong)(zhong)的(de)(de)(de)營養物質為食,所以可(ke)以大量(liang)消滅(mie)農林害(hai)蟲(chong)(chong)(chong)(chong)(chong);雌馬(ma)尼蜂(feng)(feng)(feng)可(ke)以把(ba)卵(luan)產(chan)在(zai)(zai)(zai)鉆入(ru)樹皮(pi)的(de)(de)(de)天牛(niu)幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong)體內(nei),以后(hou)它的(de)(de)(de)幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong)便以天牛(niu)幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong)為食,直(zhi)至吃得只剩一(yi)層皮(pi)。當它發現(xian)鱗(lin)翅(chi)(chi)(chi)目幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong)后(hou)便落到它的(de)(de)(de)頭部,用(yong)長針狀(zhuang)的(de)(de)(de)產(chan)卵(luan)器刺入(ru)其(qi)腦部,實施麻碎后(hou)被(bei)寄(ji)生(sheng)(sheng)(sheng)幼(you)(you)(you)(you)(you)蟲(chong)(chong)(chong)(chong)(chong)便昏迷不醒,然后(hou)被(bei)“劫”入(ru)穴中(zhong)(zhong)(zhong),產(chan)卵(luan)其(qi)中(zhong)(zhong)(zhong);其(qi)他如(ru)金小蜂(feng)(feng)(feng)、姬(ji)蜂(feng)(feng)(feng)、小繭蜂(feng)(feng)(feng)等是消滅(mie)害(hai)蟲(chong)(chong)(chong)(chong)(chong)的(de)(de)(de)能手。左圖是用(yong)赤(chi)眼(yan)蜂(feng)(feng)(feng)防治(zhi)玉米(mi)螟(ming)(ming),掛在(zai)(zai)(zai)玉米(mi)葉子上是赤(chi)眼(yan)蜂(feng)(feng)(feng)的(de)(de)(de)卵(luan)塊,每(mei)個(ge)(ge)小白球里有(you)(you)40多(duo)個(ge)(ge)赤(chi)眼(yan)蜂(feng)(feng)(feng)卵(luan)。
黑青小蜂(Dibrachys xavus)棉紅(hong)鈴蟲(chong)等的(de)(de)天敵,金小蜂科。雌(ci)成(cheng)蟲(chong)體長約2.8毫米(mi),黑色,翅透明有金屬光澤,腹(fu)部(bu)紡(fang)錘(chui)形。雄成(cheng)蟲(chong)體長約2毫米(mi),腹(fu)部(bu)第一(yi)、二節間(jian)有半透明的(de)(de)黃白(bai)色帶。年生11-12代。在越冬結繭的(de)(de)棉紅(hong)鈴蟲(chong)幼蟲(chong)體上(shang)寄(ji)生,使其死亡(wang)。用于防(fang)治(zhi)棉花倉(cang)(cang)庫內的(de)(de)棉紅(hong)鈴蟲(chong),倉(cang)(cang)庫內放蜂后,寄(ji)生率(lv)很高(gao)。
與捕食(shi)(shi)性昆蟲(chong)不同(tong)的是,寄(ji)生性昆蟲(chong)一(yi)般都(dou)是成蟲(chong)積極(ji)地尋找寄(ji)主,當發(fa)現寄(ji)主后(hou)(hou)(hou),將卵產(chan)于體內。幼蟲(chong)孵(fu)化后(hou)(hou)(hou)取食(shi)(shi)寄(ji)主的營(ying)養,和寄(ji)主共生一(yi)段(duan)時間后(hou)(hou)(hou)才使寄(ji)主死亡。幼蟲(chong)不能主動尋找食(shi)(shi)物(wu)。
寄生蜂產的幼卵安靜地躺在夢幻般的薄紗結構中。雌性寄生(sheng)(sheng)蜂(feng)通常會(hui)將幼(you)(you)卵(luan)(luan)(luan)注入毛(mao)(mao)(mao)毛(mao)(mao)(mao)蟲(chong)體內,當(dang)幼(you)(you)卵(luan)(luan)(luan)在毛(mao)(mao)(mao)毛(mao)(mao)(mao)蟲(chong)體內發(fa)育(yu)14天左右,就會(hui)變得(de)非常難看。寄(ji)生(sheng)(sheng)蜂(feng)在毛(mao)(mao)(mao)毛(mao)(mao)(mao)蟲(chong)體內排卵(luan)(luan)(luan)發(fa)育(yu)是自然界中(zhong)一種奇特的生(sheng)(sheng)物學攻(gong)(gong)擊(ji)(ji),寄(ji)生(sheng)(sheng)蜂(feng)幼(you)(you)卵(luan)(luan)(luan)使用(yong)其DNA中(zhong)的一種病(bing)毒使毛(mao)(mao)(mao)毛(mao)(mao)(mao)蟲(chong)處于麻痹(bi)狀態(tai)。受傷的毛(mao)(mao)(mao)毛(mao)(mao)(mao)蟲(chong)顯(xian)然被病(bing)毒所(suo)嚴重影響,它(ta)在幼(you)(you)卵(luan)(luan)(luan)旁建造了(le)絲毯結構,對這些攻(gong)(gong)擊(ji)(ji)者進行防(fang)御,然而在這種發(fa)育(yu)環境(jing)下(xia),寄(ji)生(sheng)(sheng)蜂(feng)幼(you)(you)卵(luan)(luan)(luan)逐(zhu)漸發(fa)育(yu),最終完全成熟,離開毛(mao)(mao)(mao)毛(mao)(mao)(mao)蟲(chong)飛向天空。