Tuyển chọn các chủng purpureocillium lilacinum có khả năng ký sinh tuyến trùng meloidogyne spp

BVTV - S6 2/2016 K6t qua nghien ciru khoa hoc to evaluate the biocontrol potential of single spore isolates of fungal entomopathogens, Journal of Insect Science, 5(37): 1-10 Sandhu S.S., Rajak R.C and Agarwal G.P.,1993 Studies on Prolonged Storage of Beauveria bassiana Conidia: Effects of Temperature and Relative Humidity on Conidial Viability and Virulence against Chickpea Borer, Helicoverpa annigera, Biocontrol Science and Technology, 3(1): 47-53 Nguyen Thi Thanh, TrAn Ngoc Lan, Nguyen Thi Thiry, 2011 Hieu lt,rc ph6ng triy sau khoang (Spodoptera litura Fabr.) cua n6rn Isaria javanica (Frider & Bally) Samsom & Hywel-Jones, Top chi Khoa hoc, Trisang Dai hoc Vinh, 40(4A): 84-89 Vega F.E., Goettelb M.S., Blackwell M., Chandler D., Jackson M.A., Keller S., Koike M., Maniania N.K., Monzon A., Ownley B.H., Pell J.K., Drauzio E.N Rangel D.E.N., Roy H.E., 2009 Fungal entomopathogens: new insights on their ecology, Fungal Ecology, 2: 149-159 Vijayavani S., Reddy K R K and Murthy G.B.V.N., 2009 Pathogenicity of Beauveria bassiana (Deuteromycotina: Euteromycotina: Hyphomycetes) strains on Spodoptera litura (Fab.), Journal of Biopesticides, 2(2): 205-207 Phan biOn: GS.TS.NCVCC Pham Van Lam TUYEN CHON CAC CHUNG Purpureocillium lilacinum CO KHA NANG KY SINH TUYEN TRUNG Meloidogyne spp Selection of Indigenous Strains of Purpureocillium lilacinum Able to Parasitize Root - Knot Nematode Meloidogyne spp Le Thi Thiry Nhi, Le Thi Mai Charm VO Thiry Duvng, Nguy6n Thi Thuy Duvng, Pham Nguyen Dim Hoang, Otrang Hoa Xo va Pham HC.ru Nhuvng Trung tam C6ng nghe Sinh hoc TP HCM Ngay chap nhan: 03.02.2016 Ngay nhan bai: 12.01.2016 Abstract Purpureocillium lilacinum can parasitize egg-shells and females cuticle of root-knot nematodes Meloidogyne spp by mechanical and/or enzymatic activities Ten indigenous isolates of P lilacinum were isolated from black pepper farms and National Parks infected with egg masses and female nematodes under in vitro conditions as an initiative to control root-knot nematodes problem All isolates showed varying degrees in colonizing egg masses and female nematodes As observed by microscopy, these strains infected egg masses and female nematodes by direct hyphae penetration In the female nematodes bioassay, all strains demonstrated highly significant colonization (>50%, P50.01) with BL16, BL10, XL1.2 showed 100% parasitism and highly radiating mycelia on females In egg masses parasitism test, these strains exhibited >30% parasitism with BL10, CM3.4, XL1.2, BGM6.1 showed >80% parasitism on root-knot nematode eggs Four indigenous strains of P lilacinum namely BL10, CM3.4, XL1.2, BGM6.1 demonstrated high and significant parasitism on egg masses and female nematodes So these strains should use as biological control agents for managing root-knot nematodes Meloidogyne spp Keywords: Purpureocillium lilacinum, Meloidogyne spp., egg mass, female, parasitism DAT VAN DE HO tieu hay tieu (Piper nigrum L.) la loaf gia vi duac sir dung nhieu 5m thcic va duoo canh tac cong nghiep tai nhieu vung Viet Nam la cuteng quoc xuat khautieu Ian nhat the giai, dOng vai trO binh on, dan dat gia Ca thi twang 24 the gioei Tuy nhien, hau het cac man tieu & Viet Nam deu bi nhiern tuyen Meloidogyne spp., lam cho tieu bi yang la chet cham Them vao dO tao vet thuang cagiai de nhieu loci nam benh Tat xam nhiern nhu: Fusarium spp., Phytophthora spp., Sclerotium rolfsii, Rhizoctonia solani la nguyen nhan chinh gay dich chet nhanh, Ket qua nghien ciru khoa hoc chet cham hien nay, lam Om dang ke nang suet h6 tieu cua Viet Nam Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel-Jones & Samson thuOc lap Sordariomycetes, b6 Hypocreales, ho Ophiocordycipitaceae, chi Purpureocillium P lilacinum 16 nem co kha nang 1(9 sinh cai va trirng tuyen trung duvc coi nhu' mOt tac nhan kiem scat sinh hoc de phong trU, tuyen trung (Luangsa-ard, 2011) P lilacinum co kha nang xam nhap kh6i trirng Meloidogyne incognita, pha hi:1y phoi va xam nhiem cai twang (Jatala va cs., 1979) He khan ti nem xam nhap qua lap vo trirng nha luc ca hoc va/hoac host dOng cua enzyme, qua trinh lay nhiem bat dew vai sy' phat then cua khan ti nem chat nen gelatine (Siddiqui va Mahmood, 1997) Khan ti nem xam nhap thOng qua cac 16 nho cua mang vitelline, gay sy' thay doi tinh them cua v6 va sty na trirng, sau d6, Ian Ong pha v& lap chitin va lap lipid lien ke P lilacinum can, co kha nang san xuat serine protease va mOt so chitinase pha hOy vo trirng, cac enzyme cung giiip nem xam nhap qua lap bieu bi cua tuyen trung (Khan va cs., 2006, Moosavi va Zare, 2012) P lilacinum la vi sinh vat thuOc he nem det, phat then nhanh va it chlu anh twang bai cac nem dOi khang, nem benh thu,c vat (Pendse va cs., 2013) Do do, co the sir dung P lilacinum la tac nhan sinh hoc kiem soat tuyen trung hieu qua, chinh vl the, chimg toi da fien hanh thin nghiem kha nang kji sinh cua cac chung P lilacinum tren cal va trirng tuyen trimg, sang loc cac chung co hieu qua cao de phuc vu cho muc dich tao the phern sinh hoc VAT LIEU VA PHUteNG PHAP NGHIEN cCni 2.1 Vat lieu nghien apu Cac chOng P lilacinum tir giOng dia Trung tam Cong nghe Sinh hoc da dvac dinh danh va dvqc khao sat hopt tinh chitinase, protese, lipase, chon 10 chung P lilacinum co hopt tinh enzyme toi vu nhet de khao sat kha nang kj/ sinh bao gom 10 chung: BL10, BL16, BS3.3 (dvac phan lap mom QuOc gia Nam Cat Tien); BN5 (man QuOc gia BO Gia Map), XL1.2, CM3.4, CM6.3 (wan tieu tinh Song Nai) va BGM6.1, LN1.2, HQ5.1 (wan tieu tinh Binh Phutec) Hai chung d6i chUng Purpureocillium lilacinum NBRC5350 (PL), Pochonia chiamydosporia NBRC10314 (PC) mua tip ngan hang giOng dia Nhat Ban Con cai va kh6i (rung tuyen trung Meloidogyne spp duac tech va thu nhan tip cac BVTV - S6 2/2016 not seri tren re cay tieu thu thep a mOt so wan tieu thuOc tinh Hong Nai va tinh Binh Phvac 2.2 Phu'o'ng phap nghien can' Chan bj mOi twang WA b6 sung 0,1 g/I chloramphenicol, help Whir trung, phan ph6i deu dia Petri vO trung Con cai va kh6i VON tuyen bao guar' King sau tech tir re cay ['vac muOi sinh ljt va dvac kh6, trung bAng cach rira len vai rarac cat v6 trung Cey nem vao giu,a dia Petri mOi tru'ang, dung kim hOt dat cai tuyen trung va kh6i trivng xung quanh nem, cach tam dia cm, nu6i cay a nhiet d6 25 ± 2°C Thi nghiem dvac 1)6 tri theo kieu hoar) toan ng5u nhien, vai len lap lei, mOi dia cai hoac khoi trirng tuyen King (Khan va cOng sy', 2006; Pau va cOng skr, 2012) Chi tieu theo dOi: Theo dal phat then cua khan ti nem, &rang kinh tan nem sau al.& nu6i cay, tinh tjf le cai, kh6i trirng tuyen trung bi ky sinh, quan sat su' xam nhap cua khan ti nem vac) tuyen trung !Deng cach nhuOm vai lactophenol blue KET QUA VA THAO LUAN Sau thi nghiem dinh tinh he enzyme ngoai bao (chitinase, protease va lipase), chon loc dvac 10 chung nem BS3.3, BL10, BL16, XL1.2, CM3.4, CM6.3, BN5, BGM6.1, LN1.2 va HQ5.1 nhet Chung tOi tiep tuc danh gia kha nang ky sinh tren trirng va cai tuyen truing Meloidogyne spp phOng thi nghiem Kha nang k9 sinh tuyen (rung nhanh hay cham phu thuOc vao phat then nhanh hay cham cua cac chUng nem tren mOi tru'ang thach nvac cat Trong thi nghiem nay, P lilacinum dat &rang kinh khoang cm thi khan ti nem bet deu tier) XCJC vai cai Nhin vac bang 1, to they &yang kinh cua chung BL16 phat then nhanh nhet, khan ti nem cham den cai chi sau ngay, cac chung nem khac thi phat trien cham hen nen &rang kinh dpt cm sau ngay, khan ti nem mai cham vao cai Ket qua twang ty' nhu' nghien c0,u cua Pau va cs (2012) thin nghiem dat cai vao dia P lilacinum de moc ngay, thi sau khan ti nem bat deu xam nhap vao cai Meloidogyne incognita, ben canh d6 Khan va Ong sy' (2006) they sau khan ti nem bao quanh cai Kha nang kj/ sinh cai cung phy thuOc vao kha nang tiet enzyme ngopi bao chitinase va lipase cua cac chung nem (Pau va cOng 25 Ket qua nghien CCFU khoa hoc BVTV - S6 2/2016 nang ky sinh cal cua tirng chung nim, chung toi theo d6i s6 tj, 10 (%) cai bi ky sinh cua tiyng chUng 2012), bang chirng la nhang chung CO khuen lac phat then nhanh la nhO,ng chUng dipac chon co chitinase manh (BL10, XL 1.2, CM3.4) va lipase manh (BL16, XL1.2) De danh gia chinh xac kha Bang Trung binh du•o'ng kinh cua cac chung nAm P lilacinum chon loc dtro,c va chung ddi chirng Purpureocillium lilacinum (PL), Pochonia chlamydosporia (PC) tren dia WA khao sat kha nang ky sinh cai Meloidogyne spp Sn Dirteng kinh tan n6rn (cm) BS3.3 1,11 1,41 BL10 1,10 1,40 Chung 14 3,83i 2,24 2,66 10 3,24 12 3,59 2,27 2,91 3,80 4,55 5,15a 4,40 4,80e BL16 1,70 2,16 3,21 3,30 3,58 CM3.4 0,76 1,09 1,58 2,26 2,78 3,29 3,75b 4,21 4,72f CM6.3 1,11 1,43 2,10 2,86 3,61 XL1.2 0,96 1,31 2,20 2,95 3,85 4,25 5,00b 3,90 4,62g 4,85d BN5 0,89 1,13 2,90 BGM6.1 1,05 1,46 1,91 2,14 3,50 2,91 3,54 4,09 0,91 1,19 2,00 2,45 2,80 3,20 3,51j 10 HQ5 LN1.2 0,85 0,97 1,80 2,49 2,86 3,43 3,91h 11 PL 1,10 1,59 2,22 3,35 3,74 4,31 4,96c 12 PC 0,80 1,09 1,61 2,01 2,55 2,83 3,40k th6ng ke mac xac suet p = 0,01) coy (Cac chic cai cuing met c6t khOng cling 1c)", thi khac bie t COnghia TY LE (%) CON CA1131 KY SINH [3 2000 ‘ I 111NG Hinh Bieu d6 so sanh ty Ie cai bi kyr sinh bai cac chung nam P lilacinum chon loc cityac va chung doi chUng Purpureocillium lilacinum (PL), Pochonia chlamydosporia (PC) (cac chi' cal tren c6t gia tri khOng cOng ky tv thi khac Piet c6 )", nghia thOng Ice a tn6c xac suet p = 0.01) Du'a vao bleu dO 1, they rang sau 14 ngay, tit ca cac chUng nim khao sat deu ky sinh tren 26 50% cai thi nghiem, do, dang ch0 nhat la cac chung BL16, BL10, XL1.2 da ky sinh het 100% cai, ke den la cac chUng CM3.4, BGM6.1, PL de ky sinh tren 80% cai Ket qua cOng tuang &yang vai su, phat trier) &rang kinh cua cac chUng nim tren m6i truteng WA, chung co kha nang ky sinh cai cao cung la chUng co &Pang kinh 16'n hen cac chung khac Quan sat dual kinh hien vi soi n6i, chOng tOi nhan they khuen ti P lilacinum co kha nang dam xuyen triic tier) qua lOp bleu bi cua cal giOng voi bao cao cua Khan va cOng su' (2006) va Pau va cOng su' (2012), khac vai bao cao dia Jatala va cOng sty (1979) P lilacinum xam nhiem cai Meloidogyne thong cac 16 ma dia co' the nhu, hau mon va am hO Hinh 2B cOng chung minh khuen ti nim (bit mau xanh cua lactophenol blue) dam xuyen tryc tiep qua lap bleu bl cua cal ma khong can cac I6 ma tren ca the, dieu ca ca the ca the tiet enzyme va ap hoc cua sqi nim giup P lilacinum dam xuyen tru'c tiep qua lap bleu bi Ket qua nghien ct:Pu khoa hoc BVTV - S6 2/2016 Hinh Con cal c6 nem ky sinh chup dutri kinh hien vi huynh quang d6 ph6ng dai 400 In A: D6i chung: cai khOng co nem ky sinh, B: Khuen ti nam (mCli ten do) xam nhep qua kip bleu bi cai, C: Khuan ti nam (mill ten de)) ben ca the cal A Hinh Con cai Meloidogyne spp bi khuen ti nem (mai ten d6) ky sinh chup diroi kinh soi not d§ ph6ng dai 45 In Con cai bi nam ky sinh: sau (A), sau 14 (B) Kha nang ky sinh khoi trCyng Meloidogyne spp cua cac chung nem P lilacinum yeu hart so vai kha nang ky sinh cai Khi nuoi nam tren mOi tnyang WA co dat cac kh6i trirng Meloidogyne spp thi chung phat then cham ham Bang the hien ket qua sau xtr ly thong ke dung kinh cua cac chung nem P lilacinum sau cap thi nghiem Kat qua khao sat kha nang ky sinh khOi trCyng tuyen trimg Meloidogyne spp cua cCia 10 chCing nam da chon cho thay, cht.ing BL16 CO kha nang phat then nhanh nhat tren mOi biking WA CO dat cac khoi trirng Meloidogyne spp (dt.rang kinh nem dat 2,113 cm sau nuoi cay) Den thir 8, mot so cht.ing nem co dutng kinh dat khoang cm (BS3.3, BL10, CM6.3, XL1.2, BGM61), thi khuan ti nem cham den khoi trtrng Khan va cong sir (2006) dat trirng tuyen trung Meloidogyne javanica vac) nem P lilacinum d5 nuoi cay thi tang bi nhiem sau 10 ngay, thi nghiem cua Pau va cong sir (2012) cho thay trCyng Meloidogyne incognita &Ito lay nhiem vai 10 bao tir P lilacinum/ml thi sau truing bi ky sinh, cac thi nghiem Mitt tien hanh tren cac trirng rieng le duac tach rod tCY kh6i trirng nen thai gian bi ky sinh nhanh han Kha nang xam nhap trirng thu6c vao kha nang tiet enzyme ngoai bao protease, lipase, CO the giOng co hoat tinh protease manh se CO kha nang ky sinh khOi trCyng cao Do dO, chung BL16 ban deu phat then nhanh (dt.yang kinh dat 2,113 cm sau nuoi cay) nhung so sanh vai thi nghiem ky sinh cai thi &yang kinh tan nam thi nghiem ky sinh khoi trirng nho hurl, chung protease yeu han Va so sanh vai cac chiing nam khac 10 thi nghiem thi BL16 phat then cham han chCmg BL10 va BS3.3 (BL10 va BS3.3 co vOng protease manh) 27 BVTV - S6 2/2016 Ket qua nghien CCM khoa hoc Bang Trung binh duVng kinh cua cac chUng nam P lilacinum chon loc duvc va chUng d6i chipng Purpureocillium lilacinum (PL), Pochonia chlamydosporia (PC) tren dia WA khao sat kha nang ky sinh tui tripng Meloidogyne spp arang kinh tan nam (cm) STT ChCing ngay ngay 10 12 14 BS3 1,10 1,31 1,89 2,24 2,49 3,01 3,45b BL10 1,10 1,40 1,90 2,51 2,80 3,39 3,80a BL16 1,61 1,78 2,11 2,15 2,19 2,39 2,61f CM3.4 0,76 1,13 1,34 1,71 1,81 2,05 2,32c CM6.3 1,05 1,29 1,71 2,00 2,10 2,45 2,53h XL1.2 0,94 1,30 1,79 2,29 2,65 2,84 3,05d BN5 1,05 1,22 1,40 1,70 1,77 2,10 2,24i BGM6.1 0,91 1,16 1,50 2,11 2,22 2,49 2,80e HQ5.1 0,91 1,05 1,45 1,76 1,90 2,13 2,251 10 LN1.2 0,81 1,10 1,38 1,69 1,85 2,20 2,55g 11 PL 1,10 1,40 1,39 1,92 2,00 2,15 2,25i 12 PC 0,81 1,03 1,19 1,49 1,55 1,70 1,80j (Cac chir cal cung nxit c6t khOng cang ky ty'thi khac biet coy nghia th6ng ke a muc xac suet p= 0,01) TV LE (%)TRO.NG 13! SINH (I I oN• c-;• 4s, Hinh Bieu dO so sanh tY,le khOi tru'ng bi ky sinh h&j cac chung nam P lilacinum va chUng dot chung Purpureocillium lilacinum (PL), Pochonia chlamydosporia (PC) sau 14 ng5y thi nghiO.n (cac chit' cal tren cot gia tri, khOng cang ky tur thi khac biet coy nghia thong kO a m6c xac suit p = 0,01) Kha nang ky sinh khoi trOng cLia cac chung nam P lilacinum dircyc chan kern han so vai ky sinh cai Bleu d6 hinh cho they, cac khoi hi:mg bi ky sinh bai cac chUng nam sau 14 28 deu ten 30% (phan tram cai bi ky sinh sau 14 ct.ia cac chOng nam deu tren 50%) Trong do, cac chCing nam CO kha nang ky sinh triing cao la BL10, CM3.4, XL1.2, BGM6.1 (dat tren 80%) (cac chung cang cO duang kinh khuen lac Ian) Thi nghiem cho thay, cac chimg nam P lilacinum phan lap &roc CO kha nang ky sinh tCti triing va cai Meloidogyne spp hieu qua han so vai cac chung nam doi chung P lilacinum va cao han chung P chlamydosporium, thi nghiem cCia Eapen va tong su' (2005) P lilacinum cOng co kha nang ky sinh cai va trtYng cao han P chlamydosporium Trong thi nghiem chCing t6i chi tap trung vao danh gia kha nang ky sinh cai va kh6i trimg tuyen trung cOa cac chung P lilacinum phan lap thn Khi nam bao vay toan b6 khoi trCrng va pha hay trCrng, chi co mot vai trUng na J2, nhien nhin hinh 5B va 5C nhan they khuen ti P lilacinum qu6n quanh ca 6u trung J2 no' tit' khoi trtYng Khan va Ong su' (2006) cang da ket luan P lilacinum co kha nang ky sinh Au trung J2, vi vay co the sir dung P lilacinum la tac nhan sinh hoc kiem scat hieu qua tuye'n trung Meloidogyne spp K6t qua nghien ciru khoa hoc BVTV - S6 2/2016 Hinh KhOi trirng Meloidogyne spp bI nAm P Illacinum kjt sinh (chyp dunfri kinh soi not dO phony 41 45 Ian) a: Nam meri titip xuc voi kh6i tn"mq, b: N6m xhm nh$p vao kh6i trirng, c: NAm phat trien fret, kh6i trepng Hinh KW& tru'ng Meloidogyne spp va Au Wing J2 bi nAm P lilacinum kjt sinh a: KhuAn ti nam bao vay va dam xuyen toan b¢ tui tram, b: KhuAn ti nArn qu.in quanh J2 va tin Ming, c: KhuaRn ti n6m quAn quanh J2 KET LUAN VA DE NGHI "fir cac ket qua thi nghiem, chCing toi chon ditivc chOng nem CO kha nang ky sinh tuyen trung hieu qua la BL10, CM3.4, XL1.2 va BGM6.1, cac chung vira CO kha nang k9 sinh cal vire co kha nang ky sinh khoi trirng tuyen trung Can khao nghiem them kha nang ky sinh au King tuy4n King cua cac chung nem, nang cao hieu qua kiem soat tuyen triang Cac chung nem c6 kha nang ky sinh cao, tiep tic thin nghiem trcrc tier) Van cay tong de chon &Ivo nhCrng chung CO kha nang kiem soat tuyen trung t6i Lru, Ur Crng dyng tato cha pharn sinh tux CO kha nang phong trir tuyen trung hieu qua TAI LIEU THAM KHAO Eapen S.J., Beena B and Ramana K.V., 2005 Tropical soil microflora of spice-based cropping systems as potential antagonists of rootknot nematodes J Invertebr Pathol., 88: 218-225 Jatala P., Tenbach K.R and Bocangel M., 1979 Biological control of Meloidogyne incognita acrita and Globodera pallida on potatoes Journal Of Nematology, 11: 303 Khan A., Williams L.K and Nevalainen K.M.H., 2006 Infection of plant-parasitic nematodes by Paecilomyces lilacinus and Monacrosporium lysipagum BioControl, 51: 659-678 Luangsa-ard J., Houbraken J., Doom V.T., Hong S.B and Borman M.A., Hywel-Jones L.N and Samson A.R., 2013 Purpureocillium, a new genus for 29 Ket qua nghien ciru khoa hoc BVTV - S6 2/2016 the medically important Paecilomyces lilacinus Federation of European Microbiological Societies Microbiol Lett., 321: 141-149 Moosavi M.R and Zare R., 2012 Chapter Fungi as Biological Control Agents of Plant-Parasitic Nematodes In Plant Defence: Biological Control Vol Merillon J.M va Ramawat K.G Progress in Biological Control Springer Sci., pp 67-107 Pau G.C et al., 2012 Isolation of Indigenous Strains of Paecilomyces lilacinus with Antagonistic Activity against Meloidogyne incognita International Journal Of Agriculture and Biology, 14: 197-203 Pendse M.A., Karwande P.P and Limaye M.N., 2013 Past, present and future of nematophagous fungi as bioagent to control plant parasitic nematodes The Journal of Plant Protection Sciences, (1): 1-9 Siddiqui Z.A and Mahmood I., 1996 Biological control of plant parasitic nematodes by fungi: A review Bioresource Technology, 58: 229-239 Phan bie-n: TS Dao Thi HAng DANH GIA HIED 14C PHONG TRU' RAY NAU HAI LUA (Nilaparvata lugens Stal.) CCM MOT S6 THUOC TRU' SAU Bio-Efficacy Evaluation of Some Insecticides Against Rice BPH (Nilaparvata lugens Stal.) Phung Minh Loci, TrAn Thanh Tung', Le Thi Dieu Trang2, H6 Thi Thu Giang3 va Taro Adati4 Ngay ch6p nhOn: 17.02.2016 Ngay nhan bat: 23.12.2015 Abstract Brown planthopper (BPH), Nilaparvata lugens is a serious pest affecting rice in Southeast Asia countries including Vietnam To deal with this pest problem, farmers rely mainly on chemical pesticide use High pressure of pesticide use has led to increase in pesticide tolerability of BPH This study aims to evaluate the bio-efficacy of some insectides which had been being used for a long period of time against BPH on rice field in Tien Giang province, Mekong Delta The insecticides used in this study were based on the recent survey on farmers pesticide use practices in the Mekong Delta In this study, two experiments were conducted in Winter - Spring (2014-2015) and Summer — Autumn (2015) season The trials were carried out by using Randomized Complete Block Design (RCBD) with treatments (7 active ingredients including buprofezin (Applaud 10WP, 1.0 kg/ha), imidacloprid (Confidor 100SL, 0.4 Uha), dinotefuran (Oshin 20WP, 0.3 kg/ha), sulfoxaflor (Closer 500WG, 0.6 kg/ha), pymetrozine (Chess 500WP, 0.3 kg/ha), fipronil (Regent 800WG, 0.04 kg/ha), fenobucarb (Bassa 50ND, 1.0 I/ha), and one untreated control) The trials were replicated times with 52.5 m2 per plot The efficacy of pesticides used in this study was determined based on the number of insect individuals (nymphs and adults) which monitored before and 1, 3, 7, 10, 14 days after treatment Results indicated that, most of the tested insecticides including buprofezin, imidacloprid, fenobucarb, fipronil and sulfoxaflor had low efficacy on BPH (less than 65%) Only two active ingredients tested (dinotefuran and pymetrozine) were still effective in controlling BPH (higher than 70% efficacy) The decline in pesticide efficacy in this study may be due to overuse of these pesticides for a long time, leading to high selection pressure on insects As a result, the development of pesticide resistance may occur Keywords: Insecticides, bio-efficacy, rice pests, brown planthopper DAT VAN DE Ray nau (Nilaparvata lugens) la mOt nhirrig dich hai quan nhat gay hai Trung tam KD&KN thuOc BVTV phia Nam Liking Dai hoc Nong lam Tp HO Chi Minh Floc vien Nong nghiep Viet Nam Dai hoc Nong nghiep Tokyo, Nhat Ban 30 nhieu niybc Chau A CO Viet Nam [20,10] Rey nau co the gay hai trcyc tier) tren cay 10a th6ng qua chich hOt, chOng cOn gay hai gian tiep vi la vac to truyen benh vi rut gay benh yang lOn va lun xoan la cho cay 10a CO nhieu loci thu6c trir sau duvc nOng dan sir dung phOng trir ray nau nhung nang suat 10a van bi Om dich hai gay Ap 11,FC sCr dung thu6c trir sau cao de dan den hien tuvng ... cac chung nAm P lilacinum chon loc dtro,c va chung ddi chirng Purpureocillium lilacinum (PL), Pochonia chlamydosporia (PC) tren dia WA khao sat kha nang ky sinh cai Meloidogyne spp Sn Dirteng... ph6ng dai 45 In Con cai bi nam ky sinh: sau (A), sau 14 (B) Kha nang ky sinh khoi trCyng Meloidogyne spp cua cac chung nem P lilacinum yeu hart so vai kha nang ky sinh cai Khi nuoi nam tren mOi... chUng nam P lilacinum chon loc duvc va chUng d6i chipng Purpureocillium lilacinum (PL), Pochonia chlamydosporia (PC) tren dia WA khao sat kha nang ky sinh tui tripng Meloidogyne spp arang kinh