天(tian)牛是多食亞目(mu)天(tian)牛科昆蟲(chong)的(de)總稱(cheng),咀嚼式口(kou)器,有很長的(de)觸角,常常超過身體的(de)長度(du),全世界約有超過20,000種。有一些種類(lei)屬于(yu)害蟲(chong),其幼蟲(chong)生活(huo)于(yu)木材中(zhong),可能對樹或建筑(zhu)物造成(cheng)危害。
天牛是植食性昆蟲,會危(wei)害木(mu)(mu)本植物,大部分(fen)松、柏、柳、榆、核桃、柑橘、蘋果、桃和茶(cha)等(deng),一部分(fen)棉、麥、玉米、高粱、甘蔗和麻等(deng),少數木(mu)(mu)材、建筑(zhu)、房屋和家具等(deng),是林業生產、作(zuo)物栽培和建筑(zhu)木(mu)(mu)材上的主要害蟲。
鞘翅目(Coleoptera)天(tian)牛(niu)科(Cerambycidae)甲蟲(chong),其英(ying)文俗名得自多(duo)(duo)數種(zhong)的(de)極長觸(chu)角(jiao)。分布(bu)全(quan)球,但熱帶最多(duo)(duo)。長0.4~18cm,不(bu)過,若把觸(chu)角(jiao)計算在內,長度可增加2~3倍。許多(duo)(duo)成蟲(chong)(如歐(ou)洲的(de)蜂(feng)形虎天(tian)牛(niu)〔Clytus arietes〕)采花粉(fen),體色黃(huang)、黑、橙相間,酷似黃(huang)蜂(feng);有(you)些虎天(tian)牛(niu)屬(shu)(Clytus)的(de)熱帶種(zhong)類(lei)(lei)貌似蟻類(lei)(lei);非洲的(de)大天(tian)牛(niu)(Pterognatha gigas)則像一塊帶有(you)幾條線(伸出的(de)觸(chu)角(jiao))的(de)苔(tai)蘚或地衣。
天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)的(de)(de)種(zhong)(zhong)(zhong)類(lei)(lei)(lei)(lei)很多,世界已(yi)知22000種(zhong)(zhong)(zhong),中國也(ye)有(you)2200種(zhong)(zhong)(zhong)左(zuo)右,分(fen)布廣泛,為害普遍(bian),幾(ji)乎每一種(zhong)(zhong)(zhong)樹(shu)木,都(dou)受不同的(de)(de)天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)種(zhong)(zhong)(zhong)類(lei)(lei)(lei)(lei)所侵害。而受害較多的(de)(de)樹(shu)木,像桑(sang)樹(shu)有(you)天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)28種(zhong)(zhong)(zhong),柳(liu)樹(shu)和(he)楊樹(shu)有(you)25種(zhong)(zhong)(zhong),柑桔類(lei)(lei)(lei)(lei)有(you)18種(zhong)(zhong)(zhong),松樹(shu)有(you)23種(zhong)(zhong)(zhong)。天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)中數量多、常見(jian)的(de)(de)除星天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)和(he)桑(sang)天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)外,還有(you)光肩星天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)、桃(tao)紅(hong)頸天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)、白筋天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)、紅(hong)緣天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)、云斑(ban)白條天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)、竹緣虎天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)、深山天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)等(deng)。典型的(de)(de)天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)種(zhong)(zhong)(zhong)類(lei)(lei)(lei)(lei)、身體呈長圓筒形(xing)(xing)(xing),背部略扁,觸角(jiao)(jiao)特(te)(te)長,特(te)(te)別是比較常見(jian)的(de)(de)幾(ji)種(zhong)(zhong)(zhong),如(ru)星天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)、桑(sang)天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)、云斑(ban)白條天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)等(deng),它們壯碩的(de)(de)軀體和(he)突出(chu)的(de)(de)兩角(jiao)(jiao),使人意識到牛(niu)(niu)(niu)(niu)(niu)(niu)的(de)(de)印象。其實天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)的(de)(de)體形(xing)(xing)(xing)大小也(ye)頗有(you)變異,有(you)的(de)(de)觸角(jiao)(jiao)較短,有(you)的(de)(de)體呈卵圓形(xing)(xing)(xing)或(huo)其它形(xing)(xing)(xing)狀,有(you)的(de)(de)則摹擬其它昆蟲的(de)(de)形(xing)(xing)(xing)象,如(ru)薔薇天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)屬、花天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)亞科很像蜂類(lei)(lei)(lei)(lei)。天(tian)牛(niu)(niu)(niu)(niu)(niu)(niu)又(you)以(yi)(yi)色(se)彩美麗著稱,但很多種(zhong)(zhong)(zhong)類(lei)(lei)(lei)(lei)或(huo)多或(huo)少呈棕褐色(se),或(huo)以(yi)(yi)花斑(ban)排列,和(he)樹(shu)干的(de)(de)顏色(se)相橡,而具有(you)隱匿色(se)或(huo)保(bao)護(hu)色(se)的(de)(de)作用。
大(da)多數天(tian)牛是大(da)型(xing)或中型(xing)的(de)種類(lei),體(ti)(ti)(ti)(ti)長(chang)(chang)在15~50mm之間。但亦有(you)很(hen)大(da)的(de)如大(da)山鋸天(tian)牛,體(ti)(ti)(ti)(ti)長(chang)(chang)可達(da)110mm,較小的(de)如微小天(tian)牛,體(ti)(ti)(ti)(ti)長(chang)(chang)僅0.5mm。同種個(ge)體(ti)(ti)(ti)(ti)之間有(you)時大(da)小變異也很(hen)大(da),如星天(tian)牛體(ti)(ti)(ti)(ti)長(chang)(chang)19~39mm,體(ti)(ti)(ti)(ti)寬6~14mm。
天牛(niu)(niu)的(de)幼蟲(chong)以(yi)及成蟲(chong)多喜在(zai)(zai)樹(shu)木上活動,如桑樹(shu)、柳樹(shu)和楊樹(shu)、柑(gan)桔(jie)類(lei)、松樹(shu)等都有多種(zhong)天牛(niu)(niu)種(zhong)類(lei)在(zai)(zai)其繁(fan)衍。天牛(niu)(niu)中數(shu)量(liang)多,對(dui)植(zhi)被危害較大(da)。
天(tian)(tian)牛(niu)(niu)的(de)(de)寄主范圍在各種類間亦(yi)有不同(tong)(tong)(tong),很多種類如(ru)(ru)星天(tian)(tian)牛(niu)(niu)、桑(sang)天(tian)(tian)牛(niu)(niu)、云斑(ban)天(tian)(tian)牛(niu)(niu)等,其食(shi)性廣泛,能加害多種不同(tong)(tong)(tong)科的(de)(de)植(zhi)(zhi)物;有的(de)(de)則限(xian)于同(tong)(tong)(tong)科或接近(jin)的(de)(de)屬,如(ru)(ru)大牙(ya)和(he)曲牙(ya)鋸天(tian)(tian)牛(niu)(niu)為害禾本(ben)科植(zhi)(zhi)物,樟(zhang)紅天(tian)(tian)牛(niu)(niu)為害樟(zhang)樹(shu)和(he)楠(nan)木樹(shu)。
天(tian)(tian)牛幼蟲淡黃或白(bai)色,天(tian)(tian)牛成蟲體(ti)呈(cheng)長圓(yuan)筒(tong)形 體(ti)前端擴展成圓(yuan)形,似頭(tou),故俗名圓(yuan)頭(tou)鉆(zhan)木(mu)蟲,上(shang)腭強壯(zhuang),能鉆(zhan)入樹內生活兩年以上(shang),破(po)壞木(mu)材(cai)。化(hua)蛹前向外鉆(zhan)一孔(kong)道(dao),在樹內化(hua)蛹,新(xin)羽化(hua)的(de)成蟲經此孔(kong)道(dao)而出(chu)。三對(dui)足,兩對(dui)翅。由于這種鉆(zhan)木(mu)習性,天(tian)(tian)牛危害木(mu)材(cai)和漿材(cai)樹、景觀(guan)(guan)樹、果(guo)樹以及木(mu)本觀(guan)(guan)賞植物(wu)甚(shen)巨。
成(cheng)蟲(chong)體(ti)呈長(chang)(chang)圓(yuan)(yuan)筒形,背部略(lve)扁;觸(chu)角著生在(zai)額的(de)(de)突(tu)起(稱(cheng)觸(chu)角基瘤)上,具(ju)(ju)有使觸(chu)角自由(you)(you)轉動和(he)向后覆蓋(gai)于(yu)蟲(chong)體(ti)背上的(de)(de)功能。爪通常呈單(dan)齒式(shi),少數呈附齒式(shi)。除鋸天(tian)牛(niu)(niu)(niu)類外(wai)(wai),中(zhong)胸(xiong)背板(ban)(ban)常具(ju)(ju)發(fa)音器。幼蟲(chong)體(ti)粗肥,呈長(chang)(chang)圓(yuan)(yuan)形,略(lve)扁,少數體(ti)細長(chang)(chang)。頭呈橫闊或長(chang)(chang)橢(tuo)圓(yuan)(yuan)形,常縮入前胸(xiong)背板(ban)(ban)很(hen)深。天(tian)牛(niu)(niu)(niu)因(yin)其(qi)力(li)大(da)(da)(da)如牛(niu)(niu)(niu),善(shan)于(yu)在(zai)天(tian)空中(zhong)飛翔,因(yin)而(er)得(de)天(tian)牛(niu)(niu)(niu)之名;又因(yin)它發(fa)出(chu)“咔嚓、咔嚓”之聲(sheng),其(qi)聲(sheng)很(hen)象是(shi)鋸樹之聲(sheng),故又被稱(cheng)作“鋸樹郎”。此外(wai)(wai),中(zhong)國南方(fang)有些地區稱(cheng)之為“水牯牛(niu)(niu)(niu)”、“水牛(niu)(niu)(niu)”等,北方(fang)有些地區稱(cheng)之為“春牛(niu)(niu)(niu)兒”。此蟲(chong)因(yin)種(zhong)類不(bu)同,體(ti)形的(de)(de)大(da)(da)(da)小(xiao)差別極(ji)大(da)(da)(da),最大(da)(da)(da)者體(ti)長(chang)(chang)可(ke)達(da)11cm,而(er)小(xiao)者體(ti)長(chang)(chang)僅(jin)0.4~0.5cm,此蟲(chong)特別的(de)(de)特征是(shi)其(qi)觸(chu)角極(ji)長(chang)(chang),中(zhong)國華北有一種(zhong)叫做長(chang)(chang)角灰天(tian)牛(niu)(niu)(niu)的(de)(de),其(qi)觸(chu)角長(chang)(chang)度可(ke)達(da)自身體(ti)長(chang)(chang)的(de)(de)4~5倍(bei),普通所見的(de)(de)天(tian)牛(niu)(niu)(niu),其(qi)觸(chu)須亦可(ke)達(da)10cm左右。另外(wai)(wai)一個特征就是(shi)它強有力(li)的(de)(de)下巴。天(tian)牛(niu)(niu)(niu)體(ti)色大(da)(da)(da)多為黑色,體(ti)上具(ju)(ju)有金屬的(de)(de)光澤,其(qi)成(cheng)蟲(chong)常見于(yu)林區、果(guo)園等處,飛行(xing)時鞘翅(chi)張開不(bu)動,由(you)(you)內翅(chi)扇動,發(fa)出(chu)“嚶(ying)嚶(ying)”之聲(sheng)。它多數為1年發(fa)生1代(dai),也有3年2代(dai)或2年一代(dai)的(de)(de),是(shi)危害(hai)楊、柳(liu)、桑、槐(huai)、梧桐(tong)、苦楝等樹木的(de)(de)
害蟲。
鋸天(tian)牛(niu)亞科:(Prioninae),鞘(qiao)翅(chi)革質,淡(dan)褐(he)色,前胸(xiong)(頭後面地區)側向擴展,緣有齒突。該亞科的松天(tian)牛(niu)屬(Parandra,或稱異天(tian)牛(niu)屬,有時列入(ru)椎天(tian)牛(niu)科〔Spondylidae〕)生(sheng)于(yu)松樹(shu)中,闊頸鋸天(tian)牛(niu)(Prionus laticollis)的幼蟲生(sheng)活在葡(pu)萄、蘋(pin)果、白楊、南方越(yue)橘和其他的果樹(shu)、觀賞樹(shu)等樹(shu)根中
花(hua)(hua)天(tian)牛(niu)(niu)亞(ya)科:(Lepturinae)。包(bao)括接骨木(mu)天(tian)牛(niu)(niu)(Desmocerus palliatus),肩部似著一黃斗篷(peng),觸(chu)角多結節(jie),故(gu)又(you)稱斗篷(peng)結節(jie)天(tian)牛(niu)(niu)(cloaked knotty-horn beetle)。取食接骨木(mu)的花(hua)(hua)和葉,幼蟲鉆入莖(jing)髓(sui)中。
溝(gou)脛天(tian)(tian)(tian)牛(niu)亞科(ke):(Lamiinae),包(bao)括墨(mo)天(tian)(tian)(tian)牛(niu)屬(Monochamus)的(de)(de)(de)食(shi)木蟲(chong)(chong),灰棕色(se),長(chang)約30公厘(1.2吋(cun)(cun),不包(bao)括長(chang)觸角)。幼蟲(chong)(chong)在松、冷(leng)杉樹(shu)(shu)(shu)內(nei)鉆孔直徑(jing)(jing)達10公厘(0.3吋(cun)(cun))。蘋(pin)圓頭(tou)天(tian)(tian)(tian)牛(niu)(Saperda candida)是(shi)一種嚴(yan)重(zhong)的(de)(de)(de)蘋(pin)果害蟲(chong)(chong)。繞枝(zhi)(zhi)溝(gou)脛天(tian)(tian)(tian)牛(niu)(Oncideres cingulata,即割枝(zhi)(zhi)天(tian)(tian)(tian)牛(niu))產卵在枝(zhi)(zhi)條(tiao)內(nei),然後(hou)沿枝(zhi)(zhi)條(tiao)圓周(zhou)割一溝(gou),後(hou)枝(zhi)(zhi)條(tiao)枯(ku)死并(bing)斷裂(lie),幼蟲(chong)(chong)在枯(ku)枝(zhi)(zhi)中發育。光肩(jian)星天(tian)(tian)(tian)牛(niu)(Anoplophora glabripennis),原(yuan)產于中國和朝鮮,是(shi)許多(duo)硬材樹(shu)(shu)(shu)的(de)(de)(de)主要害蟲(chong)(chong),尤其(qi)是(shi)對楓樹(shu)(shu)(shu)、白蠟槭、七葉(xie)樹(shu)(shu)(shu)(馬(ma)栗)、鹿眼樹(shu)(shu)(shu)、柳(liu)樹(shu)(shu)(shu)和榆樹(shu)(shu)(shu)。成(cheng)蟲(chong)(chong)亮黑色(se),有不規(gui)則的(de)(de)(de)白點,體大,長(chang)1.9~3.8cm(0.75~1.5吋(cun)(cun))。觸角黑色(se)帶有白環(huan),長(chang)3.8~10.2cm(1.5~4吋(cun)(cun))。在夏日數月中,成(cheng)年雌蟲(chong)(chong)嚼(jiao)碎(sui)樹(shu)(shu)(shu)皮產卵,造成(cheng)樹(shu)(shu)(shu)木一個(ge)直徑(jing)(jing)約1.3cm(0.5吋(cun)(cun))的(de)(de)(de)明顯深色(se)傷疤。待幼蟲(chong)(chong)孵出後(hou),移棲樹(shu)(shu)(shu)心處,在那里(li)取食(shi)、發育成(cheng)熟,然後(hou)挖洞(dong)出來,留下9.5公厘(0.375吋(cun)(cun))寬(kuan)的(de)(de)(de)洞(dong)。據說光肩(jian)星天(tian)(tian)(tian)牛(niu)是(shi)跟著貨(huo)板(ban)運送(song)到(dao)北美,1996年使紐約蟲(chong)(chong)患(huan)成(cheng)災,幾年之後(hou)又(you)傳(chuan)到(dao)新澤西、伊利諾州的(de)(de)(de)芝加哥和安(an)大略省的(de)(de)(de)多(duo)倫(lun)多(duo)。防治(zhi)措施包(bao)括移除和銷(xiao)毀樹(shu)(shu)(shu)木,隔離受傳(chuan)染的(de)(de)(de)疫區、嚴(yan)格管(guan)控木材的(de)(de)(de)運送(song),并(bing)用殺蟲(chong)(chong)劑治(zhi)療,把光肩(jian)星天(tian)(tian)(tian)牛(niu)限制在隔離區內(nei)。
天(tian)(tian)牛(niu)(niu)(niu)是(shi)(shi)(shi)人們(men)熟知(zhi)的(de)一類昆(kun)蟲(chong)。很多人在(zai)孩童時期,曾經(jing)捕捉(zhuo)到或觀察到天(tian)(tian)牛(niu)(niu)(niu),對它(ta)們(men)發生興趣。有(you)(you)趣的(de)是(shi)(shi)(shi)當你抓(zhua)住它(ta)時,會發出“嘎吱嘎吱”聲(sheng)響,企圖掙脫逃命(ming)。如(ru)若在(zai)其腿上(shang)縛一根細線,任其飛翔(xiang),還(huan)能聽到“嚶嚶”之聲(sheng)呢。天(tian)(tian)牛(niu)(niu)(niu)的(de)玩(wan)法很多,如(ru)天(tian)(tian)牛(niu)(niu)(niu)賽跑、天(tian)(tian)牛(niu)(niu)(niu)拉車、天(tian)(tian)牛(niu)(niu)(niu)釣(diao)魚(yu)、天(tian)(tian)牛(niu)(niu)(niu)賽叫等等,比起(qi)充斥市場的(de)電動(dong)玩(wan)具來(lai),玩(wan)這種“自然寵物”要有(you)(you)趣得多。不(bu)(bu)過在(zai)這里要提(ti)醒(xing)大家(jia),在(zai)玩(wan)的(de)時候(hou),當心別被(bei)天(tian)(tian)牛(niu)(niu)(niu)強壯(zhuang)的(de)上(shang)顎咬著手(shou)(shou)! 在(zai)民(min)間(jian)流(liu)行一種“天(tian)(tian)牛(niu)(niu)(niu)釣(diao)魚(yu)”的(de)游戲,十(shi)分逗人開(kai)懷。方法是(shi)(shi)(shi)在(zai)一盛水(shui)(shui)的(de)盆中,置(zhi)一魚(yu)形(xing)小(xiao)片,穿孔系線,另(ling)一頭系在(zai)天(tian)(tian)牛(niu)(niu)(niu)角上(shang),線長適度,將(jiang)天(tian)(tian)牛(niu)(niu)(niu)置(zhi)于另(ling)一小(xiao)木條上(shang),浮于水(shui)(shui)面(mian),天(tian)(tian)牛(niu)(niu)(niu)四周環(huan)水(shui)(shui),局促(cu)不(bu)(bu)安(an),頻(pin)頻(pin)揮動(dong)觸角,形(xing)同(tong)釣(diao)魚(yu),魚(yu)若離水(shui)(shui),則釣(diao)魚(yu)成功。如(ru)兩蟲(chong)比賽,以先(xian)釣(diao)起(qi)者為勝(sheng),十(shi)分有(you)(you)趣。天(tian)(tian)牛(niu)(niu)(niu)年齡(ling)稍大些的(de)有(you)(you)手(shou)(shou)指那么粗,年齡(ling)小(xiao)一些的(de)差(cha)不(bu)(bu)多只(zhi)有(you)(you)鉛(qian)筆一般細。
天牛(niu)一般以幼(you)(you)蟲(chong)(chong)或(huo)(huo)(huo)成(cheng)(cheng)(cheng)(cheng)蟲(chong)(chong)在(zai)樹(shu)(shu)干(gan)內(nei)(nei)越(yue)冬。成(cheng)(cheng)(cheng)(cheng)蟲(chong)(chong)羽化后(hou)(hou),有(you)的需進行補(bu)充(chong)營(ying)養(yang),取(qu)食(shi)花粉、嫩枝(zhi)、嫩葉、樹(shu)(shu)皮、樹(shu)(shu)汁或(huo)(huo)(huo)果實、菌(jun)類等,有(you)的不需補(bu)充(chong)營(ying)養(yang)。成(cheng)(cheng)(cheng)(cheng)蟲(chong)(chong)壽(shou)命(ming)一般10余天至1~2個月(yue);但在(zai)蛹室內(nei)(nei)越(yue)冬的成(cheng)(cheng)(cheng)(cheng)蟲(chong)(chong)可(ke)達7~8個月(yue),雄蟲(chong)(chong)壽(shou)命(ming)比雌蟲(chong)(chong)短。成(cheng)(cheng)(cheng)(cheng)蟲(chong)(chong)活動(dong)時(shi)間(jian)與復眼小(xiao)(xiao)眼面(mian)(mian)粗、細有(you)關(guan),一般小(xiao)(xiao)眼面(mian)(mian)粗的,多在(zai)晚上(shang)活動(dong),有(you)趨光(guang)性;小(xiao)(xiao)眼面(mian)(mian)細的,多在(zai)白天活動(dong)。成(cheng)(cheng)(cheng)(cheng)蟲(chong)(chong)產卵(luan)方式(shi)(shi)與口(kou)(kou)器形式(shi)(shi)有(you)關(guan),一般前口(kou)(kou)式(shi)(shi)的成(cheng)(cheng)(cheng)(cheng)蟲(chong)(chong)產卵(luan)時(shi)將卵(luan)直接產入粗糙樹(shu)(shu)皮或(huo)(huo)(huo)裂(lie)縫中;下口(kou)(kou)式(shi)(shi)的成(cheng)(cheng)(cheng)(cheng)蟲(chong)(chong)先在(zai)樹(shu)(shu)干(gan)上(shang)咬成(cheng)(cheng)(cheng)(cheng)刻槽,然后(hou)(hou)將卵(luan)產在(zai)刻槽內(nei)(nei)。天牛(niu)主要以幼(you)(you)蟲(chong)(chong)蛀(zhu)(zhu)食(shi),生活時(shi)間(jian)長(chang),對(dui)樹(shu)(shu)干(gan)危害嚴重。當卵(luan)孵化出幼(you)(you)蟲(chong)(chong)后(hou)(hou),初齡幼(you)(you)蟲(chong)(chong)即蛀(zhu)(zhu)入樹(shu)(shu)干(gan),最初在(zai)樹(shu)(shu)皮下取(qu)食(shi),待齡期增大后(hou)(hou),即鉆入木(mu)質部為害,有(you)的種類僅(jin)停留在(zai)樹(shu)(shu)皮下生活,不蛀(zhu)(zhu)入木(mu)質部。幼(you)(you)蟲(chong)(chong)在(zai)樹(shu)(shu)干(gan)內(nei)(nei)活動(dong),蛀(zhu)(zhu)食(shi)隧道的形狀和長(chang)短隨(sui)種類而異。幼(you)(you)蟲(chong)(chong)在(zai)樹(shu)(shu)干(gan)或(huo)(huo)(huo)枝(zhi)條上(shang)蛀(zhu)(zhu)食(shi),在(zai)一定(ding)距離內(nei)(nei)向(xiang)樹(shu)(shu)皮上(shang)開口(kou)(kou)作為通氣孔,向(xiang)外推出排泄物和木(mu)屑。幼(you)(you)蟲(chong)(chong)老熟后(hou)(hou)即筑成(cheng)(cheng)(cheng)(cheng)較寬的蛹室,兩端以纖(xian)維和木(mu)屑堵塞,而在(zai)其(qi)中化蛹。蛹期約10~20多天。
天(tian)(tian)牛(niu)(niu)的(de)幼(you)蟲蛀食樹(shu)干(gan)(gan)和樹(shu)枝,影響樹(shu)木的(de)生長發(fa)育,使樹(shu)勢衰(shuai)弱,導致(zhi)病(bing)菌侵(qin)入(ru),也(ye)易被(bei)風(feng)折斷。受害嚴重(zhong)時,整株死亡,木材被(bei)蛀,失去工(gong)藝(yi)價值(zhi)。天(tian)(tian)牛(niu)(niu)主要(yao)是木本植物的(de)害蟲,在(zai)幼(you)蟲期蛀蝕樹(shu)干(gan)(gan)、枝條及根部。有一部分(fen)為害草本植物,幼(you)蟲生活于莖或根內,如菊(ju)天(tian)(tian)牛(niu)(niu)、瓜藤天(tian)(tian)牛(niu)(niu)等(deng)。個別種(zhong)(zhong)類(lei)如棉(mian)蒴天(tian)(tian)牛(niu)(niu),則為害棉(mian)蒴。還有少數種(zhong)(zhong)類(lei),幼(you)蟲不生活在(zai)植物組織內,而是在(zai)土壤中取(qu)食根部,如大牙及曲(qu)牙鋸天(tian)(tian)牛(niu)(niu)、草天(tian)(tian)牛(niu)(niu)等(deng)等(deng)。
關于成蟲的(de)食(shi)(shi)性,已知有(you)取(qu)食(shi)(shi)花粉(fen)、嫩(nen)樹(shu)皮(pi)、嫩(nen)枝、葉、根(gen)、樹(shu)汁、果實、菌(jun)類等不(bu)(bu)同習(xi)性。一般說(shuo)來,花天牛(niu)類常以花粉(fen)為(wei)食(shi)(shi)。溝脛天牛(niu)類常食(shi)(shi)害嫩(nen)樹(shu)皮(pi)、嫩(nen)枝和葉。其它亞(ya)科(ke)的(de)成蟲亦有(you)取(qu)食(shi)(shi)的(de),亦有(you)一部分可能并(bing)不(bu)(bu)取(qu)食(shi)(shi)。在同一亞(ya)科(ke)內食(shi)(shi)性的(de)變異亦很(hen)大。
天(tian)(tian)(tian)牛生活(huo)(huo)(huo)史(shi)的(de)(de)(de)(de)(de)(de)長(chang)短依種(zhong)類(lei)而異,有(you)一(yi)年(nian)(nian)完成(cheng)(cheng)1代(dai)(dai)或(huo)2代(dai)(dai)的(de)(de)(de)(de)(de)(de),也有(you)二(er)、三(san)年(nian)(nian)甚至四、五年(nian)(nian)完成(cheng)(cheng)1代(dai)(dai)的(de)(de)(de)(de)(de)(de)。同(tong)(tong)(tong)一(yi)種(zhong)類(lei)在(zai)(zai)(zai)(zai)不(bu)同(tong)(tong)(tong)地(di)(di)域的(de)(de)(de)(de)(de)(de)生活(huo)(huo)(huo)史(shi)有(you)時亦(yi)很(hen)不(bu)同(tong)(tong)(tong),如黃星桑(sang)天(tian)(tian)(tian)牛在(zai)(zai)(zai)(zai)江蘇需三(san)年(nian)(nian)完成(cheng)(cheng)一(yi)世代(dai)(dai),而在(zai)(zai)(zai)(zai)廣(guang)東則(ze)一(yi)年(nian)(nian)發(fa)生兩代(dai)(dai)。由(you)于(yu)幼蟲(chong)(chong)(chong)(chong)的(de)(de)(de)(de)(de)(de)隱藏(zang)生活(huo)(huo)(huo),對(dui)(dui)它(ta)們進生活(huo)(huo)(huo)史(shi)觀察很(hen)有(you)困難(nan)。又由(you)于(yu)寄主植物的(de)(de)(de)(de)(de)(de)條(tiao)(tiao)件如老(lao)幼、健康、干(gan)濕程度等,對(dui)(dui)幼蟲(chong)(chong)(chong)(chong)的(de)(de)(de)(de)(de)(de)長(chang)發(fa)育(yu)影響很(hen)大。不(bu)良條(tiao)(tiao)件常引(yin)起(qi)幼蟲(chong)(chong)(chong)(chong)的(de)(de)(de)(de)(de)(de)滯育(yu)而使生活(huo)(huo)(huo)世代(dai)(dai)大大地(di)(di)延(yan)長(chang)。所(suo)以同(tong)(tong)(tong)-種(zhong)類(lei)在(zai)(zai)(zai)(zai)同(tong)(tong)(tong)一(yi)地(di)(di)區內(nei)(nei)(nei)(nei)可能(neng)呈現(xian)不(bu)同(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)發(fa)育(yu)過(guo)程。文獻上有(you)許多(duo)關(guan)于(yu)長(chang)壽(shou)幼蟲(chong)(chong)(chong)(chong)的(de)(de)(de)(de)(de)(de)記,這些大都是(shi)根據木材制成(cheng)(cheng)了家具(ju)后,經過(guo)若干(gan)年(nian)(nian)代(dai)(dai),忽然發(fa)現(xian)其中尚有(you)生存的(de)(de)(de)(de)(de)(de)天(tian)(tian)(tian)幼蟲(chong)(chong)(chong)(chong),或(huo)者天(tian)(tian)(tian)牛忽然羽(yu)化而此證明它(ta)在(zai)(zai)(zai)(zai)木器(qi)內(nei)(nei)(nei)(nei)已(yi)生活(huo)(huo)(huo)了很(hen)多(duo)年(nian)(nian)代(dai)(dai)。已(yi)有(you)很(hen)多(duo)這樣的(de)(de)(de)(de)(de)(de)例子,證明天(tian)(tian)(tian)牛幼蟲(chong)(chong)(chong)(chong)可以生活(huo)(huo)(huo)到(dao)(dao)一(yi)、二(er)十(shi)年(nian)(nian),而最(zui)高(gao)的(de)(de)(de)(de)(de)(de)2個(ge)記錄是(shi)40年(nian)(nian)和45年(nian)(nian)。天(tian)(tian)(tian)牛一(yi)般以幼蟲(chong)(chong)(chong)(chong)越冬(dong)(dong),或(huo)以成(cheng)(cheng)蟲(chong)(chong)(chong)(chong)在(zai)(zai)(zai)(zai)蛹室內(nei)(nei)(nei)(nei)越冬(dong)(dong),即(ji)上一(yi)年(nian)(nian)秋冬(dong)(dong)之(zhi)際羽(yu)化的(de)(de)(de)(de)(de)(de)成(cheng)(cheng)蟲(chong)(chong)(chong)(chong),留(liu)在(zai)(zai)(zai)(zai)蛹室內(nei)(nei)(nei)(nei)到(dao)(dao)翌年(nian)(nian)春夏間(jian)才出來。成(cheng)(cheng)蟲(chong)(chong)(chong)(chong)的(de)(de)(de)(de)(de)(de)壽(shou)命一(yi)般不(bu)長(chang),十(shi)數天(tian)(tian)(tian)到(dao)(dao)一(yi)、二(er)個(ge)月(yue),但在(zai)(zai)(zai)(zai)蛹室內(nei)(nei)(nei)(nei)越冬(dong)(dong)的(de)(de)(de)(de)(de)(de)成(cheng)(cheng)蟲(chong)(chong)(chong)(chong)可能(neng)達到(dao)(dao)七(qi)、八個(ge)月(yue)。雄蟲(chong)(chong)(chong)(chong)壽(shou)命一(yi)般較雌(ci)蟲(chong)(chong)(chong)(chong)為(wei)短。成(cheng)(cheng)蟲(chong)(chong)(chong)(chong)活(huo)(huo)(huo)動(dong)的(de)(de)(de)(de)(de)(de)時間(jian)在(zai)(zai)(zai)(zai)各種(zhong)類(lei)間(jian)也各有(you)不(bu)同(tong)(tong)(tong),有(you)的(de)(de)(de)(de)(de)(de)在(zai)(zai)(zai)(zai)白天(tian)(tian)(tian)日(ri)光下活(huo)(huo)(huo)動(dong),活(huo)(huo)(huo)躍的(de)(de)(de)(de)(de)(de)是(shi)花(hua)天(tian)(tian)(tian)牛類(lei);有(you)的(de)(de)(de)(de)(de)(de)則(ze)在(zai)(zai)(zai)(zai)夜晚或(huo)陰天(tian)(tian)(tian)活(huo)(huo)(huo)動(dong),或(huo)整晚都能(neng)活(huo)(huo)(huo)動(dong)。
產(chan)(chan)卵(luan)(luan)(luan)(luan)方式(shi):主(zhu)要有(you)兩(liang)種,一(yi)種是雌(ci)蟲在產(chan)(chan)前(qian)先(xian)用(yong)上(shang)顎咬破樹(shu)皮(特別是溝脛天牛), 然后用(yong)產(chan)(chan)卵(luan)(luan)(luan)(luan)管插入,每孔(kong)產(chan)(chan)卵(luan)(luan)(luan)(luan)一(yi)粒,也有(you)產(chan)(chan)多粒的。這樣(yang)形成的產(chan)(chan)卵(luan)(luan)(luan)(luan)孔(kong),其形狀(zhuang)大小在各(ge)種類間常有(you)不(bu)(bu)同,有(you)的很顯(xian)著(zhu),在防治上(shang)可作搜(sou)滅蟲卵(luan)(luan)(luan)(luan)的指示。另一(yi)種產(chan)(chan)卵(luan)(luan)(luan)(luan)方式(shi)不(bu)(bu)先(xian)咬孔(kong),而是直接用(yong)產(chan)(chan)卵(luan)(luan)(luan)(luan)管在樹(shu)皮縫(feng)隙內(nei)產(chan)(chan)卵(luan)(luan)(luan)(luan)。在少(shao)數(shu)情(qing)況下(xia),也有(you)產(chan)(chan)在枝(zhi)干(gan)光滑部(bu)分的。士居種類產(chan)(chan)卵(luan)(luan)(luan)(luan)于土壤內(nei)。
初孵(fu)的幼蟲(chong)一般先在(zai)(zai)皮(pi)下(xia)蛀食,經過或(huo)(huo)(huo)長(chang)或(huo)(huo)(huo)短的時(shi)(shi)期(qi)后才深入到木(mu)質部分。少數種(zhong)(zhong)類(lei)(lei)僅在(zai)(zai)皮(pi)下(xia)蛀蝕。也有的種(zhong)(zhong)類(lei)(lei)則(ze)穿(chuan)鑿(zao)(zao)不深,僅在(zai)(zai)邊材部為(wei)害。許多種(zhong)(zhong)類(lei)(lei)侵害基干或(huo)(huo)(huo)粗枝,有的在(zai)(zai)根干,有的則(ze)在(zai)(zai)枝條(tiao)蛀蝕。幼蟲(chong)蛀蝕時(shi)(shi)穿(chuan)鑿(zao)(zao)各種(zhong)(zhong)坑道(dao),或(huo)(huo)(huo)上或(huo)(huo)(huo)下(xia),或(huo)(huo)(huo)左(zuo)或(huo)(huo)(huo)右,或(huo)(huo)(huo)彎(wan)或(huo)(huo)(huo)直,隨種(zhong)(zhong)類(lei)(lei)而異,但(dan)也有許多種(zhong)(zhong)類(lei)(lei)的坑道(dao)很不規則(ze)。在(zai)(zai)坑道(dao)內常充(chong)滿蟲(chong)糞(fen)及纖(xian)維(wei)質木(mu)屑.有時(shi)(shi)蟲(chong)糞(fen)木(mu)屑由蟲(chong)孔向外排出,有時(shi)(shi)受害處(chu)并有樹(shu)汁流出。老熟幼蟲(chong)常筑成較寬的坑道(dao)作為(wei)蛹室,兩(liang)端以(yi)纖(xian)維(wei)木(mu)屑封(feng)閉,在(zai)(zai)其中化(hua)蛹。