HQI NGHj CON TRCING HQC QUOC GIA LAN THCT 7 - HA NQI 2011
NGHIEN CtfU TRONG PHONG A N H HU'ANG COA M O T S 6 T H U O C TRLP S A U D^N ONG Cotesia plutellae (Hymenoptera: Braconidae)
KY SINH SAU NON SAU TO
nh Thi Thu Giang Trudng Dgi hpc Nong nghifp Hd Npi
MO BAU
Phong trir sinh hoc sau liai bang Ice thii tit niiien da dat diroc tihirng thanh cong dang Ic^ (Barclay, 1982). Nhung viec sir dung con triing ky sinh rong rai trong phong trir sau hai mu6n dat hieu qua cao phai dua vao s\r ket hgp voi cac bien phap phong chong khac ki ca bSng thu6c trir sau (Croft, 1990). Bien phap sinh hgc va hoa hgc thuong dgi lap nhau hoi vi thuoc hoa hpc gay nen sir giam dang kS quan the cac loai co ich, dac biet khi ma cac loai djch hai da phat trien tinh khang thuoc. Cotesia plutellae va Bacillus thuringlensis da dugrc su dung ciing voi nhau co hidu qua trong chuong trinh quan ly djch h ^ tfing hop (IPM). Chuong trinh IPM sau hai tren rau co hiSu qua nliat neu si^
dung thuoc hoa hgc co ph6 tac dgng hep, co Idta nang tieu diet dich hai nhung phai an toan cho thien dich. S\r lira chgn dung thuoc, dung thoi diem phun se bao ve duoc tiiiSn dich vJ thhnh cong trong phong trii (Waage, 1992). Kit qua nghien cilu trong phong thi ngliiem nham xac dinh nhiing anh hucmg ciia mOt s6 thu6c trir sau den C. plutellae, tii do CO thS la CO so dS xuit ssf l\ra chgn thu6c trir sSu va thoi diem xii ly thudc thich hgp trong chirong trinh IPM sau hai rau.
V.^T Lifiu VA PEfUONG PHAP NGHIEN CUtJ
Nhan nu6i vSt chii sau to Plutella xylostella va ong ky sinh sau non Colesia plutellae va ong ky sinh nhgng Diadromus collaris dugc thuc hien theo quy trinh ciia Talekar era/., 1997.
Nghien cilu toh huong cua thu6c d6i vcri ong ky sinh dugc thuc hien theo phucmg phap cua Mani (1984); Suey - Sheng Kao (1992) va Idris (1993). Chiing toi sil dung cac loai thuoc nong dan thucmg sil dung trdn d6ng rugng do la Cartap (Padan 95SP), Fipronil (Regent 800WG), Etofenprox (Trebon lOEC), Cypermethrin (Sherpa 25EC), Diafenthiuron (Pegasus 500SC), Fenvalerate (Sumicidin 20EC) va Bacillus thuringlensis var. kurstaki (Delfin WG).
D6i voi ong trucmg thanh: Chiing toi dimg 1 bang gfky Igc kich thu6c 12 x 2 cm nhiing vao dung dich thuSc r8i hong kho trong khoang 30 phiit hoJc Wu hon (tuy theo toe dg gio va do am khong khi) sau do cho vko 1 6ng nghiem 20 x 2,5 cm, trong do da co 10 ong tr- udng thanh 1 ngay tu6i. Sau 6 gio tidp xiic chuydn toan bg sd ong sang ong nghidm sach dd quan sat s6 ong sdng sau 1,12,24,36,48 giij xur ly. Ong duo'c an mat ong nguyen chit.
HOI NGHI cON TRCING HOC QUOc GIA LAN THO' 7 - HA NQI 2011
Boi vdi pha nh^ng; Chiing toi sil dvng 20 nhpng (ken) 1, 2, 3, 4 ngay tudi dan deu ldn 1 to giay thim sau d6 phun dung dich thuoc ldn kdn vi hong kho dudi bdng r&n. S6 ken duoc xu 1^ voi cac cdng thiic thu6c khdc nhau dugc dat vao trong dia petri s?ch Mdi cdng thiic 5 lin nhic lai. Nhiing ong truang thanh vu hoi tir cic nhdng da xil IJ thudc tidp tuc theo doi ty 1? chet sau vu hoa 24 gid.
Ddi vdi iu triing ong ky sinh d trong vat chu: Cit la cai bip thanh cdc mau 14 aS dudng kinh 12 cm roi nhiing vdo thuoc d cdc cdng thiic trong 3 gidy sau dd de hong kho trong 2 gid. Cdng thilc ddi chiing xit 1^ Id cdi bip bang nude IS cdc miu Id bip cdi dat ldn mdnh giiy rdi cho vdo dia petri. M5i dia cd 5 sau non tuoi 2 - 3 vat chi da bj kJ sinh. Moi cdng thilc duoc nhic lai 4 lin. So sau non chdt dugc ghi Iji sau 24, 48 vd 72 gid. Bo tri thi nghiem ddi chiing tuong tif ddi vdi sau non khdng bi k^ sinh.
Sd lidu dugc xil ly theo phuomg phdp thong ke StatView va hidu dinh theo cdng thiic Abbott
KET QUA VA THAO LUAN
Mih; dg anh hudng cua thuoc sau den giai dojn phat dye cua nh$ng ong C plutellae Dd thi 1 cho thiy, ty Id vu hod ciia nhdng 3, 4 ngdy tudi cao hon nh^ng 1, 2 ngay tudi, song qua xu ly thong kd d dd tin c|y 95% ty le vu hod cua ong C. plutellae is cdc thdi ky phat due cua kdn 1 - 4 ngay tudi sau khi xil ly cdc loai thudc khdc nhau la khdng cd su sai khac.
Dd thi 1. Anh hudng cdc logt thudc sdu din tyl^vu hod ciia nhpng ong C. plutellae cd ngdy tudi khdc nhau
HOI NGHI CON T R C I N G HOC QUOC G I A LAN THCf 7 - HA NQI 2011
Dd danh gid diy dii hom tdc dgng cua thuoc trit sau ddn pha nhgng, chiing tdi tidp tuc theo ddi site s6ng ciia ong trudng thanh sau 24 gid vu hod tCi kdn dugc xil ly thudc sau nhim ddnh gid xem su phdn huy cung nhu du lupng cua thudc cd dnh hudmg ddn ong trudng thdnh khdng.
So sdnh sif dnh hudng ciia thudc sau khdc nhau ddi vdi giai do?n phdt due ciia nhdng ong (kdn) den ty le song sdt cila trudng thanh sau 24 gid vii hda. Ket qud ttinh bay d btog 1 cho thiy, ty Id chdt cao nhit ciia cdc trudng thdnh vii hod tii nhgng 1 ngdy tudi d cdng thilc xir ly thudc Padan Id 25,56%, tiep theo la Regent; Pegasus; Sherpa;
Sumicidi; Trebon va Delfin theo thii tv 22,94; 16,35; 10,78; 8.71; 2,22 vd 2,08%.
Ty Id chet cua trudng thanh vii hod tir nhgng cd thdi gian phat dye 2 ngay tu6i cao nhit la Regent 16,25%. Ty Id chdt ciia trudng thanh vii hod tir nhgng cd thdi gian phdt due 3, 4 ngdy thip hom 10%. So lidu cho thiy ty Id chdt cua tnrdng thdnh mdi vu hod gidm khi tuoi nhgng gid hon.
Bang 1. Ty If chit (%) ciia ong sau 24 gid vii hoa tir cac nhgng d3 xii' !}> thuic trir sau
L09I thu6c Regent 800WG Padan 95SP Pegasus 500SC Sherpa 10EC Sumicidin 20EC Trebon 10EC Delfin WG
Ken 1 ngdy 22,94"
25,56"
16.35*
10,78"
8,71"
2,22"
2,08'
Kdn 2 ngdy 16,25""
la.os' 13,61"
8,04' 7,95"
5,88"
3,81"
K6n 3 ngdy 5,93' 8,68' 5,19' 4,23"
3,94"
2,22"
0"
KAn 4 ngdy
7,92' 5,13' 3,98"
1,75*
3,51"
4,17"
2,38"
Giii chii: Trong ph^m vi hang, cung chQ cdi chi s\i sai kh^c khdng cd ^ nghia, kh^c chtt cdi chi sif khac nhau c6 •$ nghia d mOrc xdc suit p ^ 0,05.
Nghien cihi M i huong cua 2 lo?ii thu6c it dpc (Trebon lOEC va Delfin WG) den hoat dpng ky sinh cua ong vu hoa tir nh^ng sau khi xu ly thu6c. s6 lieu biing 2 cho thay, thuoc dS \km giAm khd nang ky sinh cua ong so voi doi chung (khong xu ly thu6c) la Trebon tir 38,30 - 52,5%. Thu6c Delfin it dnh huong din kha nang ky sinh cua ong, ty le giam ky sinh tir 8,33 - 34,88%.
Bang 2. So sdnh anh huong cua thuoc sSu den ty If ky sinh cua ong C plutellae trong phdng thf nghifm
Thu6c sdu
Trebon 10EC Deifin WG
N i n g d$
0,2%
0,25%
Ty 1$ k]^ sinh gidm so v6i d6i chCpng sau cdc ngdy xi> 1]^ thu6c (%) 1 ngdy
38,30"
8,33""
3 ngdy 36,36"
15.15"
5 ngdy 46,06"
3 4 , 8 8 "
7 ngdy 52,50' 32,60'
HQI NGHI CON T R D N G HQC QUOC GIA LAN THO' 7 - HA NQI 2011
Anh hudng cua thuoc tri^ sau doi vdi pha trudng thdnh ong k^ sinh C. plutellae Kit qua thuc nghidm trong phdng nghien ciiu sir dnh hudng ciia thudc trit sau iin pha trudng thdnh ong ky sinh dugc thi hidn qua bdng 3 cho thiy cdc loai thu6c Padan va Regent cd tdc dgng gay chdt nhanh va mpnh (ty le chet cua ong sau 24 gid xu ly Id 100% so vdi ddi chting), tidp theo dd Id Sheipa, Pegasus, Trebon vdo 48 gid sau khi tiep xiic vdi thudc, co ty Id ong chit Id 62,1 - 100%. Doi vdi thuoc Delfin tj Id chit ciia ong so vdi d6i chirng thip nhit Id 34,5% sau 48 gid \it 1^ thudc
Bang 3. Anh hudng cua mpt so lo^i thuoc trii' sau doi vdi pha trudng thdnh ong k^ sinh Cotesia plutellae
Lo^i thu6c Padan 95SP Regent 800WG Sherpa 10EC Pegasus 500SC Trebon 10EC Delfin WG
Nong d9 0,1%
0,1%
0,1%
0,17%
0,2%
0,25%
T^ 1$ ChSt ("/a) cua ong sau cdc thm gian xi> ly thudc so VO'I ddi chiing
1 h 40,0 0,0 3,3 0,0 0 0,0
12 h 90,0 63,3 26,7 30,0 36,7 0,0
24 h 100 100 60,0 66,7 46,7 3,3
36 h
83,3 76,7 60,0 10,0
48 h
100 89,7 62,1 34,5
Anh hudng cua m$t so lo^i thuoc den sir song sot ciia ong non cua ong ky sinh trong k^ chu
Ngodi dnh hudng ddi vdi pha nhdng va ong tnrdng thdnh thuoc trir sau ciing cd dnh hudng ddn sau ong non (iu triing) ciia ong C plutellae phdt tridn d trong ky chii. Nghidn Cliu cua Ahmad vd Forgash (1976); Ahmad et al. (1978) cho thiy, ong non (iu triing) cua ong ky sinh Apanteles melanoscelus bi chet bdi Carbatyl va B. thuringlensis, nhung nhung sau non ky chu bi ky sinh it min cam vdi 2 loai thudc nay horn sdu non khdng bi k^
sinh. Thi nghidm trong phdng da nghidn ciru ddnh gid anh hudng ciia mdt s6 lo?i thudc ddn su sdng sdt ciia ong non cua ong k;^ sinh (iu trimg ong) trong k^ chii. Nhiing thdng tin nay quan trong giup cho khd nang sit dung ong ky sinh trong chucmg trinh qudn ly dich hai tong hop (IPM) cd hidu qud hon. Kdt qud trinh bdy d bdng 4 cho tiiiy, sau 24 gid xit ly, thudc Peagsus, Sherpa gdy ty 1? chet ciia sau non sau to bi ky smh thip hon sau non khdng bi t y sinh. Sau 48 vd 72 gid tidp xiic vdi thuoc thi ty I? chdt ciia sdu non bi k^ sinh vd khdng bj ky sinh deu tSng cao, kd cd thuoc sinh hoc Delfin gay nen tj Id chet cua sau khdng bi ky sinh la 68,42% vd 78,95% sau bi ky smh, nhu vay thu6c sinh hoc Defm cd tac ddng ddn au trimg ong ky sinh phdt trien trong k^ chd. Kit qua ciia chiing tdi gidng nhu nhan xet cua Idris and Grafius (1993), Chilcutt va Tabashnik (1997): Su dung thudc chpn loc nhu Bacillus thuringlensis ndi chung Id it gdy hai ddn nhgng va trudng thdnh k^
sinh nhung cd the gay tac hai den ong non ky smh do su chdt cua ky chd, theo Beckwith vd Stelzer (1987) cho lang vin cd the sd dyng thuoc sinh hoc trdn rugng vi sau khi bi ky sinh ndn siic an ciia sau non vdt chu gidm, kdt hgp vdi su phdn huy ciia thudc B.
thuringlensis a ngodi ddng rugng nhanh do do cQng lam giam tdi miic thip nhit su tdc dgng gdy d$c cua thu6c len vat chii bi ky sinh.
HQI NGHI CON TRONG HQC QU6C GIA LAN THtf 7 - HA NOI 2011
Bang 4. Hieu lyc cua mgt s i lo^i t h u i c t r i r sau d i i v d i sau tor b j vd khong b j k^ sinh
Lo^i thu6c
Regent 800WG Padan 95SP Pegasus 500SC Sherpa 10EC Trebon 10EC [3ellin WG
N6ng d4
0,1%
0,1%
0,17%
0.1%
0,2%
0,25%
T^ 1$ (%) c h i t cua sdu tor sau cac thori gian xi> lj thu6c 24h
BiKS 75,0 100 35,0 45,0 60,0 10,0
Khang b| KS 70,0 95,0 40,0 50,0 55,0 5,0
4Sh BjKS
100
-
73,68 52,63 84,21 47,37
Khdng bj KS 89,47
• 100 63,16 68,42 57,89 42.11
72h BiKS
- -
89,47 84,2 100 78,95
Kh6ng bi KS 94,74
-
89,47 94,74 84,2 68,42
K ^ T L U ^
Cac loai thu6c tru sSu Id Padan 95SP, Regent 800WG, Trebon lOEC, Sherpa 25EC, Pegasus 500SC va Delfin WG diu co dnh huomg gay chit din ong non (iu triing) cua ong C plutellae phdt trien 6 trong ky chi s^u to, sau 3 ngdy xur Iy ty le chet ciia ky chit sau to bj k^ smh tir 78,95 - 100%.
Ty 1^ chit cua trudng thdnh mdi vu hoa trong thai gian 24 gio tu nhong xii ly thuoc gidm khi tuoi nhong gia hon, nh§ng c6 thoi gian phat due 3, 4 ngdy c6 tj' I§ chit duoi 10%. Thu6c tru sau Padan vd Regent deu co tdc dong gay chit nhanh pha truong thanh ong ky sinh ty 1^ chit cua ong sau 24 gifir xu 1^ la 100%. Sherpa, Pegasus, Trebon vdo 48 gi6 sau khi tilp xuc voi thuoc c6 ty le ong chit la 62,1 - 100%. Doi v(5i thu6c Delfin ty le chit ciia ong so voi d6i chiing thip nhdt Id 34,5% sau 48 gio xii ly thu6c TAI Ll£U THAM KHAO
1. Barclay, H. J., 1982. Models for pest control using predator release, habit management and pesticides release in combination. J. Appl. Ecol. 19, pp. 337 - 348.
2. Chilcutt C. F. and Bruce E. Tabashnik, 1999. Effects of Bacillus thuringlensis on adults of Cotesia plutellae (Hymenoptera: Braconidae), a Parasitoid ofthe Diamondback Moth, Plutella xylostella (Lepidoptera: Plutellidae). Biocontrol Science and Technology 9, pp.
435 - 440.
3. Croft B. A., 1990. Arthropod biological control agents and pesticides. Wiley, New York.
4. Ho Thi Thu Giang, Nguyen Viet Tung, Keiji Takasu and Kazuo Ogata, 2001. Development and host - stage selection by a Vietnamese strain of the larval parasitoid Cotesia plutellae Kurdjumov (Hymenqstera: Braconidae). Bull. Inst Trop. Agr. Kyushu Univ. 24, pp. 11 -18.
5. Ho Thj Thu Giang, 2002. Nghien ciru thien djch sau hai rau hp Hoa th$p tu; d^c dilm sinh hpc, sinh thai ciia loai ong Cotesia plutellae (Kurdjumov) vd Diadromus collaris Gravenhorst lq? sinh tren sau to Plutella xylostella (Liimaeus) a ngoai thdnh Hd Npi. Lu^n an Tien sT Nong nghiep, Truong D^i hpc Nong nghi?p Ha Npi.
6. Nguyin Van Hai, 2001. Mpt vdi mo hinh sir dyng thuoc hpp ly trir sau to h^I rau cdi bSp.
T^p chi Bao v? thvc v|it 2: 16 - 19.
HOI NGHI C O N T R C I N S HQC QUOC GIA LAN THCr 7 - HA NQI 2011
7. Idris A. B., and E. Grafius, 1993. Pesticides affect immature stages otDiadegma insulare (Hymenoptera: Ichneumonidae) and its host, the Diamondback moth (Lepidoptera:
Plutellidae), J. Econ. Entomol. 86 (4), pp. 1203 - 1212.
8. Mani M. and A. Krishnamoorthy, 1984. Toxicity of some insecticides to Apantelaes plutellae, a parasite ofthe Diamond back moth. Tropical Pest Management 30 (2), pp.130 - 132.
9. Phjm Bmh Quy^n, Nguyin Vdn San, Vu Minh Hoa, Ph?ra Vi^t Hung, 1996. Hi$n trjing sir dyng thuoc bdo ve tivfc vat vdi nhimg van de moi trudng a Dong bdng s6ng Hong, Thong bdo khoa hgc cua cac trucmg dai hpc Sinh hgc - N6ng nghiep - Y hoc, tr. 42 - 46.
10. Suey-Sheng Kao and Ching-Chou Tzeng, 1992. Toxicity of Insecticides to Cotesia plutellae, a Parasitoid of Diamondback Moth.. In Management of Diamondback Moth and other Crucifer Pets: Proc. 2"*. Inter. Workshop (N. S. Talekar eds.), Shanhua, Taiwan, AVRDC. pp. 287-296.
11. Talekar N. S., 1997. Rearing of diamondbaclc moth parasiteis. Asian vegetable research and development center 16 pp.
* T h i m dinh khoa hgc: GS.TS. Nguyen Van Dinh - T r u d n g Dai hoc N6ng nghiep H 4 N 6 i .
S U M M A R Y
STUDY O N THE TOXICITY O F C O M M O N L Y U S E D INSECTICIDES APPLIED T O Cotes/a plutellae ( H y m e n o p t e r a : B r a c o n i d a e ) A S PARASITOID
O F T H E DIAMONDBACK M O T H
Ho Thi Thu Giang Hanoi University ofAgricullure
Cotesia plutellae is an endoparasltold of larvae of the Diamondback moth (DBI\^) Plutella xylostella.
This parasitoid plays an important role in the suppression of the DBM population. We evaluated toxicity of commonly used insecticides to Cotesia plutellae. Our results shown tfiat the insecticides kill 78.95 -100%
of C. plutellae larvae indirectly by killing the hosts. Mortality of the hosts occurred 3 days after treatment Most insecticides were highly toxic to C. plutellae adults, except the less toxic Delfin W G . We tested the toxicity of the insecticides to the pupal stage of C. plutellae. There were no Significant differences of percentage emergence between the four pupal ages after treatment Mortality of newly emerged adults (1 day old) from pupae treated with Padan 95SP and Regent 800WG were highest (25.56% and 22.94%, respectively). Mortality of newly emerged adults 3 and 4 day old pupae treated with insecticides was very low (< 10%). The use of Bacillus thudngiensis had fewer adverse effects on the parasitoids, particulariy on the pupal stsge of the parasitoid.
Key words: Ong ky sinh, C^tesie plutellae, Diamonback moth, insecticides, biological control.
