寄生(sheng)蜂(feng)(feng)(feng)(Parasitoid wasp),指膜翅(chi)目細(xi)腰(yao)亞目中金小蜂(feng)(feng)(feng)科(ke)(ke)、姬蜂(feng)(feng)(feng)科(ke)(ke)、小蜂(feng)(feng)(feng)科(ke)(ke)等靠寄生(sheng)生(sheng)活的多(duo)種昆蟲(chong)(chong)。它們(men)的寄生(sheng)方式很多(duo),被寄生(sheng)對(dui)象從卵(luan)到(dao)成蟲(chong)(chong)的各(ge)個階段,都可能被寄生(sheng)。所謂寄生(sheng)蜂(feng)(feng)(feng),就是(shi)從植食(shi)性(xing)蜂(feng)(feng)(feng)類進化到(dao)筑(zhu)巢性(xing)期間的一群肉食(shi)性(xing)蜂(feng)(feng)(feng)類。與(yu)寄生(sheng)蟲(chong)(chong)一樣。
分成外寄(ji)(ji)(ji)生(sheng)和(he)內寄(ji)(ji)(ji)生(sheng)兩大類(lei)。前者是指把卵(luan)產在寄(ji)(ji)(ji)主(zhu)體(ti)(ti)表(biao),讓孵(fu)化的(de)幼蟲(chong)從體(ti)(ti)表(biao)取(qu)食寄(ji)(ji)(ji)主(zhu)身體(ti)(ti);后者是把卵(luan)產在寄(ji)(ji)(ji)主(zhu)體(ti)(ti)內,讓孵(fu)化的(de)幼蟲(chong)取(qu)食害蟲(chong)體(ti)(ti)內的(de)組織。內寄(ji)(ji)(ji)生(sheng)形式者,被認為(wei)較為(wei)進化。
外(wai)(wai)寄(ji)(ji)生(sheng)者在(zai)產(chan)卵(luan)(luan)前,必須(xu)克服(fu)一(yi)件事,就(jiu)是得讓寄(ji)(ji)主(zhu)(zhu)(zhu)無(wu)法動彈,否則卵(luan)(luan)會(hui)(hui)被寄(ji)(ji)主(zhu)(zhu)(zhu)壓壞(huai),甚至被寄(ji)(ji)主(zhu)(zhu)(zhu)咬死。因(yin)此(ci),外(wai)(wai)寄(ji)(ji)生(sheng)蜂(feng)會(hui)(hui)先用(yong)產(chan)卵(luan)(luan)管蜇刺寄(ji)(ji)主(zhu)(zhu)(zhu),注(zhu)射有毒物質麻痹寄(ji)(ji)主(zhu)(zhu)(zhu)。也(ye)就(jiu)是說,產(chan)卵(luan)(luan)管除了(le)產(chan)卵(luan)(luan)功能外(wai)(wai),兼具(ju)注(zhu)入(ru)麻醉(zui)液的(de)(de)功能。此(ci)外(wai)(wai),還有一(yi)個待(dai)解決的(de)(de)問(wen)題(ti)(ti),就(jiu)是寄(ji)(ji)主(zhu)(zhu)(zhu)必須(xu)有造繭性等隱蔽身體(ti)的(de)(de)習性,因(yin)為寄(ji)(ji)主(zhu)(zhu)(zhu)若遭麻醉(zui),行(xing)動變(bian)得遲鈍,容易受到(dao)敵害攻擊(ji)或其他外(wai)(wai)在(zai)環境的(de)(de)傷(shang)害,如果沒有隱蔽自己的(de)(de)絕活,體(ti)表的(de)(de)寄(ji)(ji)生(sheng)蜂(feng)幼蟲也(ye)將會(hui)(hui)與它同歸(gui)于盡(jin)。而采用(yong)內寄(ji)(ji)生(sheng)方式(shi)的(de)(de)寄(ji)(ji)生(sheng)蜂(feng),問(wen)題(ti)(ti)就(jiu)沒有那么嚴(yan)重。
此外,也有像蜘(zhi)(zhi)蛛(zhu)(zhu)姬蜂這類(lei)具有產卵(luan)特技寄生(sheng)蜂,它(ta)們(men)以蜘(zhi)(zhi)蛛(zhu)(zhu)網上(shang)的蜘(zhi)(zhi)蛛(zhu)(zhu)為寄主。當它(ta)突襲蜘(zhi)(zhi)蛛(zhu)(zhu)時,會先(xian)刺(ci)蜇(zhe)蜘(zhi)(zhi)蛛(zhu)(zhu)腳(jiao)(jiao)的基部(bu)(bu),利用其暫(zan)時失去感覺之際(ji),在它(ta)的頭(tou)胸部(bu)(bu)或腹部(bu)(bu)腹面(mian)產下一粒卵(luan),蜘(zhi)(zhi)蛛(zhu)(zhu)后來雖然恢復知覺,但由于腳(jiao)(jiao)摳不到卵(luan),只好任由孵化的姬蜂幼蟲吸血(xue),而終至死亡。
寄生(sheng)蜂(feng)的種類很多,分別寄生(sheng)于寄主的不同發育階段,常見(jian)的有小(xiao)蜂(feng)、姬蜂(feng)、繭蜂(feng)、赤眼蜂(feng)、嚙小(xiao)蜂(feng)等。
姬(ji)(ji)蜂(feng)(feng)(feng)(feng)(feng)是(shi)(shi)膜(mo)翅(chi)(chi)目(mu)姬(ji)(ji)蜂(feng)(feng)(feng)(feng)(feng)科(ke)的(de)一種(zhong)寄(ji)(ji)生(sheng)(sheng)(sheng)蜂(feng)(feng)(feng)(feng)(feng),膜(mo)翅(chi)(chi)目(mu)(Hymenoptera)姬(ji)(ji)蜂(feng)(feng)(feng)(feng)(feng)科(ke)(Ichneunmonidae,有重要(yao)經濟意義的(de)一個(ge)大科(ke))昆(kun)蟲(chong)(chong)(chong)(chong)(chong)(chong)。分布很廣,約40,000種(zhong)。形狀(zhuang)(zhuang)、顏(yan)色、大小各異,一般1.2公(gong)(gong)分(約0.5寸)長(chang)(chang)(chang)(chang)。北美(mei)洲最長(chang)(chang)(chang)(chang)的(de)長(chang)(chang)(chang)(chang)針姬(ji)(ji)蜂(feng)(feng)(feng)(feng)(feng)屬達5公(gong)(gong)分。許多種(zhong)的(de)腹(fu)部(bu)(bu)細(xi)長(chang)(chang)(chang)(chang)而彎曲,像黃蜂(feng)(feng)(feng)(feng)(feng),區別一般在(zai)(zai)于觸角較(jiao)長(chang)(chang)(chang)(chang),節較(jiao)多。產卵(luan)(luan)(luan)(luan)器通常(chang)比身體(ti)(ti)(ti)長(chang)(chang)(chang)(chang)。許多種(zhong)的(de)前翅(chi)(chi)有一黑(hei)點。寄(ji)(ji)生(sheng)(sheng)(sheng)在(zai)(zai)蜘蛛以(yi)(yi)及(ji)多類昆(kun)蟲(chong)(chong)(chong)(chong)(chong)(chong)上(shang),尤(you)其(qi)(qi)是(shi)(shi)鱗(lin)翅(chi)(chi)目(mu)和其(qi)(qi)他(ta)膜(mo)翅(chi)(chi)目(mu)昆(kun)蟲(chong)(chong)(chong)(chong)(chong)(chong)。由(you)于寄(ji)(ji)生(sheng)(sheng)(sheng)在(zai)(zai)許多害蟲(chong)(chong)(chong)(chong)(chong)(chong)上(shang),總的(de)來(lai)說是(shi)(shi)益蟲(chong)(chong)(chong)(chong)(chong)(chong)。雌蜂(feng)(feng)(feng)(feng)(feng)在(zai)(zai)宿(su)主(zhu)的(de)幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong)或蛹(很少在(zai)(zai)卵(luan)(luan)(luan)(luan)或成體(ti)(ti)(ti))上(shang)產卵(luan)(luan)(luan)(luan)。幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong)取食(shi)宿(su)主(zhu)的(de)脂肪和體(ti)(ti)(ti)液,長(chang)(chang)(chang)(chang)成后(hou)織(zhi)一繭。如(ru)果宿(su)主(zhu)生(sheng)(sheng)(sheng)活場所(suo)不(bu)是(shi)(shi)隱蔽的(de),則通常(chang)寄(ji)(ji)生(sheng)(sheng)(sheng)在(zai)(zai)宿(su)主(zhu)體(ti)(ti)(ti)內(nei)(nei)(nei);若(ruo)宿(su)主(zhu)生(sheng)(sheng)(sheng)活在(zai)(zai)隱蔽處(如(ru)樹木(mu)孔道內(nei)(nei)(nei)),則常(chang)寄(ji)(ji)生(sheng)(sheng)(sheng)在(zai)(zai)宿(su)主(zhu)體(ti)(ti)(ti)姬(ji)(ji)蜂(feng)(feng)(feng)(feng)(feng)外。一個(ge)宿(su)主(zhu)上(shang)多數只(zhi)有一個(ge)幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong),但有時也可(ke)(ke)有多個(ge)幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong)寄(ji)(ji)生(sheng)(sheng)(sheng)。赤眼蜂(feng)(feng)(feng)(feng)(feng)以(yi)(yi)眼紅色而得(de)名,它經常(chang)把卵(luan)(luan)(luan)(luan)產在(zai)(zai)松(song)毛蟲(chong)(chong)(chong)(chong)(chong)(chong)、玉米螟(ming)、二化螟(ming)及(ji)甘蔗螟(ming)的(de)卵(luan)(luan)(luan)(luan)中,幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong)就以(yi)(yi)寄(ji)(ji)生(sheng)(sheng)(sheng)卵(luan)(luan)(luan)(luan)中的(de)營養物質為(wei)食(shi),所(suo)以(yi)(yi)可(ke)(ke)以(yi)(yi)大量消滅(mie)農林害蟲(chong)(chong)(chong)(chong)(chong)(chong);雌馬尼蜂(feng)(feng)(feng)(feng)(feng)可(ke)(ke)以(yi)(yi)把卵(luan)(luan)(luan)(luan)產在(zai)(zai)鉆入樹皮的(de)天(tian)牛幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong)體(ti)(ti)(ti)內(nei)(nei)(nei),以(yi)(yi)后(hou)它的(de)幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong)便(bian)以(yi)(yi)天(tian)牛幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong)為(wei)食(shi),直至吃得(de)只(zhi)剩一層皮。當(dang)它發(fa)現鱗(lin)翅(chi)(chi)目(mu)幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong)后(hou)便(bian)落(luo)到(dao)它的(de)頭部(bu)(bu),用長(chang)(chang)(chang)(chang)針狀(zhuang)(zhuang)的(de)產卵(luan)(luan)(luan)(luan)器刺入其(qi)(qi)腦部(bu)(bu),實施麻碎后(hou)被寄(ji)(ji)生(sheng)(sheng)(sheng)幼(you)(you)蟲(chong)(chong)(chong)(chong)(chong)(chong)便(bian)昏迷不(bu)醒(xing),然后(hou)被“劫”入穴中,產卵(luan)(luan)(luan)(luan)其(qi)(qi)中;其(qi)(qi)他(ta)如(ru)金小蜂(feng)(feng)(feng)(feng)(feng)、姬(ji)(ji)蜂(feng)(feng)(feng)(feng)(feng)、小繭蜂(feng)(feng)(feng)(feng)(feng)等是(shi)(shi)消滅(mie)害蟲(chong)(chong)(chong)(chong)(chong)(chong)的(de)能手。左圖是(shi)(shi)用赤眼蜂(feng)(feng)(feng)(feng)(feng)防治玉米螟(ming),掛在(zai)(zai)玉米葉子上(shang)是(shi)(shi)赤眼蜂(feng)(feng)(feng)(feng)(feng)的(de)卵(luan)(luan)(luan)(luan)塊,每個(ge)小白球里有40多個(ge)赤眼蜂(feng)(feng)(feng)(feng)(feng)卵(luan)(luan)(luan)(luan)。
黑青小蜂(feng)(Dibrachys xavus)棉紅(hong)(hong)鈴(ling)蟲(chong)等的天敵,金小蜂(feng)科。雌成蟲(chong)體(ti)(ti)長約2.8毫(hao)米,黑色(se),翅透明有金屬光(guang)澤,腹部紡(fang)錘形。雄成蟲(chong)體(ti)(ti)長約2毫(hao)米,腹部第一、二節間有半透明的黃白色(se)帶。年生(sheng)(sheng)11-12代。在越(yue)冬結繭的棉紅(hong)(hong)鈴(ling)蟲(chong)幼蟲(chong)體(ti)(ti)上寄生(sheng)(sheng),使其死亡。用于防治棉花倉庫內的棉紅(hong)(hong)鈴(ling)蟲(chong),倉庫內放蜂(feng)后,寄生(sheng)(sheng)率很高。
與(yu)捕食性昆蟲不同(tong)的(de)是,寄生性昆蟲一般(ban)都是成(cheng)蟲積極地(di)尋找寄主,當發(fa)現寄主后(hou),將卵產于體內。幼蟲孵(fu)化后(hou)取食寄主的(de)營養,和(he)寄主共生一段時間后(hou)才使(shi)寄主死(si)亡。幼蟲不能主動尋找食物(wu)。
寄生蜂產的幼卵安靜地躺在夢幻般的薄紗結構中。雌性寄生蜂(feng)通常(chang)會將幼卵(luan)(luan)注入毛(mao)(mao)毛(mao)(mao)蟲(chong)(chong)體(ti)(ti)內(nei),當幼卵(luan)(luan)在(zai)毛(mao)(mao)毛(mao)(mao)蟲(chong)(chong)體(ti)(ti)內(nei)發育(yu)14天左右,就會變得非(fei)常(chang)難看。寄生蜂(feng)在(zai)毛(mao)(mao)毛(mao)(mao)蟲(chong)(chong)體(ti)(ti)內(nei)排卵(luan)(luan)發育(yu)是(shi)自然界(jie)中一種奇特(te)的生物(wu)學攻(gong)擊(ji),寄生蜂(feng)幼卵(luan)(luan)使用(yong)其(qi)DNA中的一種病毒使毛(mao)(mao)毛(mao)(mao)蟲(chong)(chong)處于(yu)麻(ma)痹狀態。受傷(shang)的毛(mao)(mao)毛(mao)(mao)蟲(chong)(chong)顯然被病毒所嚴重影響(xiang),它(ta)在(zai)幼卵(luan)(luan)旁建造(zao)了絲毯結構,對這(zhe)些攻(gong)擊(ji)者進行防御(yu),然而在(zai)這(zhe)種發育(yu)環(huan)境下,寄生蜂(feng)幼卵(luan)(luan)逐(zhu)漸發育(yu),最終完全成熟,離開毛(mao)(mao)毛(mao)(mao)蟲(chong)(chong)飛(fei)向天空(kong)。