寄(ji)(ji)生(sheng)蜂(feng)(feng)(Parasitoid wasp),指膜翅目(mu)細腰(yao)亞目(mu)中金小蜂(feng)(feng)科、姬蜂(feng)(feng)科、小蜂(feng)(feng)科等靠(kao)寄(ji)(ji)生(sheng)生(sheng)活的多(duo)種(zhong)昆蟲(chong)。它們的寄(ji)(ji)生(sheng)方式(shi)很多(duo),被寄(ji)(ji)生(sheng)對象從卵到成蟲(chong)的各個(ge)階段,都(dou)可能被寄(ji)(ji)生(sheng)。所(suo)謂寄(ji)(ji)生(sheng)蜂(feng)(feng),就是從植食性(xing)蜂(feng)(feng)類(lei)(lei)進化到筑(zhu)巢性(xing)期間的一群(qun)肉食性(xing)蜂(feng)(feng)類(lei)(lei)。與寄(ji)(ji)生(sheng)蟲(chong)一樣。
分成(cheng)外寄生和內(nei)(nei)寄生兩大(da)類(lei)。前者(zhe)是指(zhi)把(ba)(ba)卵產在(zai)寄主(zhu)體(ti)表,讓(rang)孵化的(de)幼蟲從體(ti)表取食寄主(zhu)身體(ti);后(hou)者(zhe)是把(ba)(ba)卵產在(zai)寄主(zhu)體(ti)內(nei)(nei),讓(rang)孵化的(de)幼蟲取食害蟲體(ti)內(nei)(nei)的(de)組織(zhi)。內(nei)(nei)寄生形式者(zhe),被認(ren)為(wei)較為(wei)進化。
外(wai)寄(ji)(ji)生(sheng)(sheng)(sheng)者在產卵(luan)(luan)前,必須(xu)克服一(yi)(yi)件事,就是(shi)得讓寄(ji)(ji)主(zhu)(zhu)無法(fa)動(dong)彈,否則卵(luan)(luan)會(hui)被寄(ji)(ji)主(zhu)(zhu)壓壞,甚至(zhi)被寄(ji)(ji)主(zhu)(zhu)咬死。因此,外(wai)寄(ji)(ji)生(sheng)(sheng)(sheng)蜂會(hui)先用(yong)(yong)產卵(luan)(luan)管(guan)蜇刺寄(ji)(ji)主(zhu)(zhu),注射(she)有(you)毒(du)物質麻痹(bi)寄(ji)(ji)主(zhu)(zhu)。也就是(shi)說,產卵(luan)(luan)管(guan)除了產卵(luan)(luan)功(gong)能外(wai),兼具(ju)注入麻醉液的功(gong)能。此外(wai),還有(you)一(yi)(yi)個(ge)待(dai)解決的問題(ti),就是(shi)寄(ji)(ji)主(zhu)(zhu)必須(xu)有(you)造繭性(xing)等隱(yin)蔽身體(ti)的習性(xing),因為寄(ji)(ji)主(zhu)(zhu)若遭麻醉,行動(dong)變得遲鈍,容易受到敵(di)害攻擊或其他外(wai)在環境的傷害,如(ru)果(guo)沒有(you)隱(yin)蔽自己(ji)的絕活,體(ti)表的寄(ji)(ji)生(sheng)(sheng)(sheng)蜂幼(you)蟲也將會(hui)與它(ta)同歸于盡。而采用(yong)(yong)內寄(ji)(ji)生(sheng)(sheng)(sheng)方式的寄(ji)(ji)生(sheng)(sheng)(sheng)蜂,問題(ti)就沒有(you)那么(me)嚴(yan)重(zhong)。
此外,也有像(xiang)蜘蛛(zhu)姬(ji)蜂這類(lei)具(ju)有產(chan)卵(luan)特技寄生蜂,它們以蜘蛛(zhu)網上的蜘蛛(zhu)為寄主。當它突襲蜘蛛(zhu)時,會先刺(ci)蜇蜘蛛(zhu)腳的基部,利用其暫時失去感覺(jue)之際,在它的頭胸部或腹部腹面產(chan)下一粒卵(luan),蜘蛛(zhu)后(hou)來雖然(ran)恢復知覺(jue),但由(you)于腳摳不到卵(luan),只好(hao)任由(you)孵化的姬(ji)蜂幼蟲吸血(xue),而終至死亡。
寄生蜂(feng)(feng)的種類很多(duo),分別寄生于寄主的不(bu)同發育階段,常見的有小(xiao)(xiao)蜂(feng)(feng)、姬蜂(feng)(feng)、繭蜂(feng)(feng)、赤眼蜂(feng)(feng)、嚙小(xiao)(xiao)蜂(feng)(feng)等。
姬蜂(feng)(feng)(feng)(feng)是(shi)(shi)膜(mo)翅(chi)(chi)目姬蜂(feng)(feng)(feng)(feng)科的(de)(de)(de)(de)(de)(de)一(yi)(yi)種寄(ji)(ji)(ji)生(sheng)(sheng)蜂(feng)(feng)(feng)(feng),膜(mo)翅(chi)(chi)目(Hymenoptera)姬蜂(feng)(feng)(feng)(feng)科(Ichneunmonidae,有重要經濟意義的(de)(de)(de)(de)(de)(de)一(yi)(yi)個(ge)大(da)科)昆蟲(chong)(chong)(chong)。分布很(hen)廣,約(yue)40,000種。形(xing)狀、顏(yan)色(se)、大(da)小各(ge)異,一(yi)(yi)般1.2公分(約(yue)0.5寸)長(chang)(chang)(chang)。北美洲最長(chang)(chang)(chang)的(de)(de)(de)(de)(de)(de)長(chang)(chang)(chang)針姬蜂(feng)(feng)(feng)(feng)屬達5公分。許多(duo)種的(de)(de)(de)(de)(de)(de)腹部細長(chang)(chang)(chang)而彎曲,像黃蜂(feng)(feng)(feng)(feng),區別(bie)一(yi)(yi)般在(zai)于觸(chu)角較長(chang)(chang)(chang),節(jie)較多(duo)。產(chan)(chan)(chan)卵(luan)器(qi)通(tong)常(chang)(chang)比(bi)身體(ti)(ti)長(chang)(chang)(chang)。許多(duo)種的(de)(de)(de)(de)(de)(de)前翅(chi)(chi)有一(yi)(yi)黑點。寄(ji)(ji)(ji)生(sheng)(sheng)在(zai)蜘蛛以及多(duo)類昆蟲(chong)(chong)(chong)上(shang),尤其(qi)是(shi)(shi)鱗翅(chi)(chi)目和其(qi)他(ta)膜(mo)翅(chi)(chi)目昆蟲(chong)(chong)(chong)。由(you)于寄(ji)(ji)(ji)生(sheng)(sheng)在(zai)許多(duo)害(hai)蟲(chong)(chong)(chong)上(shang),總(zong)的(de)(de)(de)(de)(de)(de)來說是(shi)(shi)益蟲(chong)(chong)(chong)。雌蜂(feng)(feng)(feng)(feng)在(zai)宿(su)(su)(su)主(zhu)(zhu)的(de)(de)(de)(de)(de)(de)幼(you)蟲(chong)(chong)(chong)或蛹(yong)(很(hen)少在(zai)卵(luan)或成體(ti)(ti))上(shang)產(chan)(chan)(chan)卵(luan)。幼(you)蟲(chong)(chong)(chong)取食(shi)(shi)宿(su)(su)(su)主(zhu)(zhu)的(de)(de)(de)(de)(de)(de)脂(zhi)肪和體(ti)(ti)液,長(chang)(chang)(chang)成后(hou)(hou)織一(yi)(yi)繭(jian)。如(ru)果宿(su)(su)(su)主(zhu)(zhu)生(sheng)(sheng)活場(chang)所不是(shi)(shi)隱蔽的(de)(de)(de)(de)(de)(de),則(ze)通(tong)常(chang)(chang)寄(ji)(ji)(ji)生(sheng)(sheng)在(zai)宿(su)(su)(su)主(zhu)(zhu)體(ti)(ti)內(nei)(nei);若宿(su)(su)(su)主(zhu)(zhu)生(sheng)(sheng)活在(zai)隱蔽處(如(ru)樹(shu)木孔道內(nei)(nei)),則(ze)常(chang)(chang)寄(ji)(ji)(ji)生(sheng)(sheng)在(zai)宿(su)(su)(su)主(zhu)(zhu)體(ti)(ti)姬蜂(feng)(feng)(feng)(feng)外。一(yi)(yi)個(ge)宿(su)(su)(su)主(zhu)(zhu)上(shang)多(duo)數(shu)只有一(yi)(yi)個(ge)幼(you)蟲(chong)(chong)(chong),但(dan)有時也可有多(duo)個(ge)幼(you)蟲(chong)(chong)(chong)寄(ji)(ji)(ji)生(sheng)(sheng)。赤(chi)眼(yan)蜂(feng)(feng)(feng)(feng)以眼(yan)紅色(se)而得(de)名(ming),它(ta)經常(chang)(chang)把(ba)卵(luan)產(chan)(chan)(chan)在(zai)松(song)毛蟲(chong)(chong)(chong)、玉(yu)米螟(ming)(ming)、二化螟(ming)(ming)及甘(gan)蔗(zhe)螟(ming)(ming)的(de)(de)(de)(de)(de)(de)卵(luan)中,幼(you)蟲(chong)(chong)(chong)就以寄(ji)(ji)(ji)生(sheng)(sheng)卵(luan)中的(de)(de)(de)(de)(de)(de)營(ying)養(yang)物質為(wei)食(shi)(shi),所以可以大(da)量(liang)消滅農(nong)林(lin)害(hai)蟲(chong)(chong)(chong);雌馬尼蜂(feng)(feng)(feng)(feng)可以把(ba)卵(luan)產(chan)(chan)(chan)在(zai)鉆入樹(shu)皮的(de)(de)(de)(de)(de)(de)天(tian)牛幼(you)蟲(chong)(chong)(chong)體(ti)(ti)內(nei)(nei),以后(hou)(hou)它(ta)的(de)(de)(de)(de)(de)(de)幼(you)蟲(chong)(chong)(chong)便以天(tian)牛幼(you)蟲(chong)(chong)(chong)為(wei)食(shi)(shi),直(zhi)至吃得(de)只剩(sheng)一(yi)(yi)層皮。當它(ta)發現鱗翅(chi)(chi)目幼(you)蟲(chong)(chong)(chong)后(hou)(hou)便落到(dao)它(ta)的(de)(de)(de)(de)(de)(de)頭(tou)部,用長(chang)(chang)(chang)針狀的(de)(de)(de)(de)(de)(de)產(chan)(chan)(chan)卵(luan)器(qi)刺(ci)入其(qi)腦部,實施麻(ma)碎后(hou)(hou)被寄(ji)(ji)(ji)生(sheng)(sheng)幼(you)蟲(chong)(chong)(chong)便昏迷不醒,然(ran)后(hou)(hou)被“劫”入穴中,產(chan)(chan)(chan)卵(luan)其(qi)中;其(qi)他(ta)如(ru)金小蜂(feng)(feng)(feng)(feng)、姬蜂(feng)(feng)(feng)(feng)、小繭(jian)蜂(feng)(feng)(feng)(feng)等是(shi)(shi)消滅害(hai)蟲(chong)(chong)(chong)的(de)(de)(de)(de)(de)(de)能手。左圖是(shi)(shi)用赤(chi)眼(yan)蜂(feng)(feng)(feng)(feng)防治玉(yu)米螟(ming)(ming),掛在(zai)玉(yu)米葉(xie)子上(shang)是(shi)(shi)赤(chi)眼(yan)蜂(feng)(feng)(feng)(feng)的(de)(de)(de)(de)(de)(de)卵(luan)塊,每個(ge)小白球(qiu)里(li)有40多(duo)個(ge)赤(chi)眼(yan)蜂(feng)(feng)(feng)(feng)卵(luan)。
黑(hei)青小(xiao)蜂(feng)(Dibrachys xavus)棉(mian)(mian)紅鈴蟲(chong)等的(de)天敵(di),金(jin)小(xiao)蜂(feng)科。雌成蟲(chong)體(ti)(ti)長約(yue)2.8毫米,黑(hei)色(se),翅透明有金(jin)屬光(guang)澤(ze),腹(fu)部紡錘形。雄成蟲(chong)體(ti)(ti)長約(yue)2毫米,腹(fu)部第一(yi)、二(er)節間有半透明的(de)黃白(bai)色(se)帶。年生11-12代。在越冬結繭(jian)的(de)棉(mian)(mian)紅鈴蟲(chong)幼蟲(chong)體(ti)(ti)上寄生,使其死亡。用于防治棉(mian)(mian)花(hua)倉庫(ku)內(nei)的(de)棉(mian)(mian)紅鈴蟲(chong),倉庫(ku)內(nei)放蜂(feng)后,寄生率(lv)很高。
與捕(bu)食(shi)性(xing)昆蟲不(bu)同的是,寄(ji)生(sheng)性(xing)昆蟲一般都(dou)是成(cheng)蟲積極(ji)地尋(xun)(xun)找寄(ji)主(zhu),當(dang)發現寄(ji)主(zhu)后(hou),將卵(luan)產于體(ti)內。幼蟲孵化后(hou)取食(shi)寄(ji)主(zhu)的營養,和寄(ji)主(zhu)共(gong)生(sheng)一段時間后(hou)才使寄(ji)主(zhu)死亡。幼蟲不(bu)能主(zhu)動尋(xun)(xun)找食(shi)物。
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)通常會將幼卵(luan)注入毛(mao)(mao)毛(mao)(mao)蟲(chong)體內,當幼卵(luan)在(zai)毛(mao)(mao)毛(mao)(mao)蟲(chong)體內發育(yu)14天左(zuo)右,就(jiu)會變得非(fei)常難看。寄生(sheng)(sheng)蜂(feng)在(zai)毛(mao)(mao)毛(mao)(mao)蟲(chong)體內排卵(luan)發育(yu)是自(zi)然界中一種奇(qi)特的生(sheng)(sheng)物學攻擊,寄生(sheng)(sheng)蜂(feng)幼卵(luan)使用其DNA中的一種病毒使毛(mao)(mao)毛(mao)(mao)蟲(chong)處于(yu)麻痹狀(zhuang)態。受傷的毛(mao)(mao)毛(mao)(mao)蟲(chong)顯然被病毒所(suo)嚴重影響,它(ta)在(zai)幼卵(luan)旁建造了(le)絲毯結(jie)構(gou),對這(zhe)些(xie)攻擊者進行防御(yu),然而在(zai)這(zhe)種發育(yu)環境下,寄生(sheng)(sheng)蜂(feng)幼卵(luan)逐漸發育(yu),最終(zhong)完全成熟,離開毛(mao)(mao)毛(mao)(mao)蟲(chong)飛向天空(kong)。