【摘要】 <正> 一.前言 白杨因适合于北半球温带而及于寒带地区生长,繁殖容易、生长迅速,所以为华北一带主要造林树种之一,尤其是营造防护林和行道树最为重要。但是在白杨幼苗生长期间,经常遭受白杨透翅蛾幼虫的为害,个别树种受害特别严重,直接影响苗圃的育苗和幼树生长。1954年北京郊区的南大荒苗圃和北京大众苗囿均有此虫为害。为了探求防治途径,保护苗木健壮生长,保证苗木供应,支援绿化全国。于1954年秋末冬初,李兆麟和殷蕙芬首先在北京大众苗圃进行检查,并套笼饲育。1955年春,周士秀和杨更多还原

【Abstract】 Toob BeTc oHo BaHx ecHx opo aHoo HacaeH epeBbeB, HacaeH-Hx Ha TpoTyape B Hae CTpaHe. OHako oH B epo pocTa BBeeH ceHa oBpeaeTc yce-HaM, Mao TooeBo CTekHH. o-HaeH aBTopoB Ha HM B TeeHe MapTa-OkTp1953 r., oBpeeHHocTb Tooe B cpeheM oCTaa o 10. 32%, Haoee-96. 1%, To cepeHoBeT Ha pocT oeceeHe ceHa. Maa TooeBa CTekHHa BeTC oCHoBHM BpeTeM Tooe B paoHe opoa ekHa.yceH aBHM opaoM oBpeaT Populus alba L., Populus tomentosa Carr,Populus simonii Carr,Populus cathayana Rehd., Populus canedensis Populus Pyramitalis Borkh. B OTHoeH Mao TooeBo cTeKHH, B By Too, TO He o oceoBaHo B HaecTpaHe, oToMy Bopoc o ee pacpocTpaHeH Han noka He ceHeH, a TaKe Heoy H KakoTepaTyp o TOm. Ma TooeBa cTekHHa BCTpeaeTc oT Bo Bcex TOMHKax oK-pecTHocTe ekHa. B CTa yceH Mana TooeBa CTekHHa HaHocT Bpe CTBoy, okoBo BeTB, oerynoke Tooe, none noBpeeH BBaTc ypeoM, BeTpoBa epeBeB opayeTc a, Bo-HKaeT oeH Tooe （Cytospora sp.）, Bce To ocaeT aTHoe CBoCTBo epeBbeB pBoTX K e. a epHoo BeTa oBabHe, eo Ha B cpeHeM 0. 9 MM, poTa-0.6 MM. Bpoca yce-Ha eBaToo BeTa. ee Ha Tea B cpeHem 3.15 CM, poTa o.oB-0.29 cM. KyKoKa ypooBeTa, ee Ha B cpeHeM 2.03 cM, poTa-0.55 cM. epeHe kpb Bpock HacekoMx TeMHo-KpHeBoo BeTa, aHe Kpb PopaHe. Maa TooeBa cTekHHa MeeT B cpeHeM 3.3 cMa paMax KpbeB, Ha Taa-1.71 CM. B ekhe k paBT oHooHH,yceHa epeMyT B xoe peBCH,B MapTe ce-yeo oa oHa HaHaeT oBpeaTb CTBo, oKykeTc B Mae. B He-e KyKoK Be-TaeT Maro. yceHa BTopoo okoeH Tae ToT xo B peBece, e poBoT eTo My. a peMyecTBeHHo oTKaBaTc Ha oBepxHoCT Kop, ocHoBaH epeka Ha oee,a TaKe B CTapx xoax paMax cTBoa. OTKaka B cpeHeM TC 10 He. yceHa ToTnpoobH xo B peBecHe BTeCHeT onK ka xoa. epo HK ocTaeT o oa.epo Kykok B cpeHeM TC 16.6 He. oce BeTa KyKok, ycTa oooka KyKokocTaerc B oTBePCT CTBoa. HeM Bpoce HacekoMe akTBHo BaTC, a Ho OH epecTaTBaTbc. o epBoHaabHM oTaM B 1955 . ycTaHoB, To epen okykeHeM CoboBaHeM TecTac CS₂ DDT akp oTBep CTe c eb yHToeH Hx, peybTaT eo xopo, cMePTHOCTyceH Ha oa 105,000 KBapaTHx MeTpoB ocTaa B cpeHeM o 95.06%.更多还原