PHAN II - XAY DUNG VA B A O VE CONG TRINH... 625
KET QUA NGHIEN CLFU SLP DUNG CHE
P H A MMETAVINA 90DP DE DIET TRLf
M 6 | COPTOTERMESFORMOSANUS (ISOPTERA: RHINOTERMITIDAE) HAI CONG TRiNH KIEN TRUC
TS. Trinh Vdn Hgnh"' Dinh Xudn Tudn
Summary:
Research on usage of Metavina 90DP to treat Coptotermes formosanus (Isoptera:
Rhinotermitidae) damaging buildings construction.
Some results in the research process show that the strain Ma 01 can cause death all individuals of termite population with 1000-4000 individules in which 10-20%
ones have innitially contaminated. Culture and form features of the strain MaCI is still stable after re-isolation.In the preservation condition at 4°C, decline level of termite treatment of MaC1 is 2,9% and 8,3% after 12 months.
I. DAT V A N Dt
Mdi C. formosanus la loai gay hai chii yeu cho cdng trinh kien tnic. de diet trii' chiing ngudi ta thudng sir dung phucmg phap lay nhiem vdi cac hoa chat dang bpt, cac hoa chit nay la nhung chit dpc hai vdi con ngudi va mdi trudng sinh thai. Tir cac ket qua nghien ciru chiing tdi da xay dyng hoan thien quy trinh va san xuat thanh cdng che phim Metavina 90DP cd ham lugng bao tir rat cao (10* - 10"'bt/g). De sir dung che pham Metavina 90DP cd hieu qua chiing tdi tien hanh nghien ciai sir dung che pham tren cic md hinh thi nghiem vdi sd lupng 1000 - 4000 ca the mdi.
II. VAT LIEU VA PHU'aNG PHAP NGHIEN ClJU
;. Vdt lieu
To mdi Coptotermes formosanus Shiraki dugc nudi tai Trung tam nghien ciiu phdng trii mdi.
Chi phim Metavina 90DP do Trung tam nghien cim phdng trir mdi san .xuat tir cac chiing nim A/. Anisopliae MaCl va MaC2.
Hop nhir. hop nhya de nudi mdi, dng nhya trang cd 0 = 1,5 cm.
' " Vien Khoa hoc Thuy Icfi Vict Nam. Nguai phan bien: GS. TS. Biii Cong Hien
2. Phwffng phdp nghiin ciru
Thi nghiem tren dTa petri: Tha 50 c i thi moi C. formosanus cua ciing td trong 1 dia petri trong dd dd chi cd mpt ti le nhd e i thi da dugc phoi nhiem trudc ydi chi pham Metavina 90DP, theo ddi sd moi chit do benh nim d Id thi nghiem v i sd mdi chet ty nhien d Id ddi chirng dl riit ra nhan xet, thi nghiem dugc lip lai 3 lan.
Thi nghiem vdi cac hop nudi: Mdi dugc nudi trong hop nhya da dugc bd sung giay cac tdng sau 15 ngay mdi tao nen trong hop nhya hinh dang td gin gidng nhu vdi td phy. Tir hop nhya ed cac ong nhira dan sang hop nhir mdi (so do bd tri thi nghiem theo hinh I). Sau khi moi da an diy cac hop nhir, thi tiin hanh bam bpt che pham Metavina 90DP len minh cac ca thi mdi nhu khi tiin hanh lay nhiem bing hoi chit [I]. Ket qui dugc dinh gii sau khi dd va kilm tra mirc dp sdng sdt ciia mdi d hop kiem tra va thiing dyng mdi sau 20 ngay thi nghiem.
Xir ly so lieu thu duge theo cdng thirc Abbot.
Hop nuoi moi
Hinh 1. Md hinh khdo nghiim thudc bdng phwffng phdp lay nhiim
Nhudm mdi mau dd de danh dau cic ca the mdi nhiem che pham ban dau bang Sudan Red 7B theo phuang phip ciia Lai, 1983 [ 3].
Che pham dugc bio qua d dieu kien 4*'C v i dieu kien nhiet do phdng tir 25 den 30"C, de kiem tra hieu lyc diet mdi cua che pham theo thdi gian d cic dieu kien b i o qua khac nhau.
III. K^T QUA NGHIEN CLFU
/. Xdc djnh ty li mdi bj nhiim chi phdm Metavina 90DP trong phong thi nghiim Cho mdi nhiem che phim Metavina 90DP vdi sd lugng khic nhau, rdi bd sung trd lai vao cac dia petri da cd mdi ban dau sao cho sd lugng mdi trong cic dia diu la 50 cac the. Sau do theo ddi ty le chet ciia mdi d cic dTa thi nghiem v i ty le mdi ehet ty nhien d cac dTa ddi chimg de riit ra nhan xet. Sd lieu thi nghiem duge trinh b i y tren bang 1.
Sd lieu tren bang 1 cho thay d tat c i cac dTa thi nghiem, dii cic ty le nhiem bao tir ban dau ciia 2 chiing M. anisopliae rat khic nhau, nhung mdi d tit c i cac Id thi nghiem deu chet hoan toan trong 9 ngay thi nghiem. Trong khi dd, mdi d cic Id ddi chimg cd ty le chit khdng dang ke (trung binh la 6,0%). Quan sit, theo ddi xic mdi chet trong cic Id tlii nghiem thay rd sy hinh thanh he sgi nam mau tring min va sau dd la sy xuit hien
PHAN II - XAY DIJNG VA BAO VE CONG TRINH.. 627
bao tir miu xanh dim die trung ciia M. anisopliae. Trong khi dd xac nhirng con mdi chet d Id ddi chung khdng cd bieu hien ciia benh do nhiem nim nay va chiing bi vi khuin phan huy rat nhanh. Dieu nay chimg td nhd tap tinh xa hpi ciia mdi, bao tu nim tir mpt sd con mdi nhiem bao tir nam M. anisopliae ban diu da lan truyen sang tat ca cac con mdi khac trong dTa thi nghiem dc gay chit cho c i nhdm moi. Kit qua phan tich cho thay chiing hai chiing MaCl va MaC2 cd hieu lire diet manh.
Bang 1. Ty le (%) moi chet do ldy nhiem che phdm Metavina 90DP tren dia petri theo thai gian thi nghiem
Chiing giong cua ch6 pham
Metavina 90DP (MaCl)
Metavina 90DP (MaC2)
^r"^ "
Ooi chu-ng Tile nhiemban diu
4 8 12
4 8 12
0 1
0 4,0
±1,0 2,5
±1,2 0 2,25
±1,1 8,0 ±
1,1 0,7
±0,3
Ty le {%) 2
8,3
±1,5 16,3
±3,2 14,3
±2,2 4,3 +1,2 12,3
±2,4 20,8+2,9
1,3
±0,3
moi chet theo thai
• ' , " ~ ! 1
j ;
3 1 4 1 5 i
h---i- . - - -
14,5 49,0
±1,8 1 ±5,0
55,5 1
±5,0 1 31,5 81,3 ' 86,3 j
±3,1 ; ±3,6 \ ±3,9 , 28,3 87,5 , 93,8
±4,8 : ±4,0 i ±4,0 10,5 , 38,0 57,5 :
±2,2 ±3.5 ±4,0 ; 46.3 : 82,0 : 87,8 :
±5,8 ; ±5,9 j ±4,8 j 53,0±5,
9 2,3
62,5±4, ! 96,3±
3 1,9 2,7 1 2,7 i
±0,3 1 ±0,7 i ±0,6 j
gian (ngay) 6 60,0 !
±5,1 i 90,5
±2,7 100 74,0
±3,5 96,3
±2,8 100 3,4 1
±0,3 : 7 88,0
±4,3 93,3
±2,7
87,8
±4,6 100
4,0
±0,6 8 93
! ±4,3 100
95,5
±3,3
5,7
±0,9 9 100
100
6,0
±0,6 Sd lieu tren bang 1 cdn cho thay khi tang ty le c i the moi bi nhiem bao tir M.
anisopliae ban diu thi thdi gian mdi chit dat 100% giam di rd ret. Vdi ty le mdi bi nhilm bao tir ban diu la 4%, so ngay mdi chet 100% la 9 ngay; vdi 8% sd ngay mdi chit 100% la 7 - 8 ngay; vdi 12% sd ngay mdi chit 100% la 6 ngay.
2. Thi nghiim ldy nhiim chung MaCl trin md hinh v&i 1000 - 4000 cd the mdi Tinh nhay cam ciia dan mdi doi vdi bao tir nam benh rat khac vdi tinh nhay cam ciia timg ca thi hoac mpt sd it ca thi trong dieu kien phdng thi nghiem. nen cac thi nghiem lay nhiem bao tir tren dia petri chua phan anh het cac tap tinh bao ve va khang lai sy lay lan bao tir trong quan thi mdi. Nhimg thir nghiem lay nhiem bao tu a cac td mdi ngoai ty nhien lai khdng thi quan sat va theo dot dugc qua trinh lay nhiem bao tu va qua trinh mdi chit do quin thi mdi ludn sdng ngam trong dit va cac vat lieu khac.
Vi nhirng ly do nhu vay chiing tdi da thilt lap cac md hinh de nghien ciru qua trinh lay
nhiem bao tir vdi sd lugng mdi tir 1000 - 4000 c i the mdi. Vdi so lugng nay, mdi cd the tao nen td phu trong vat lieu cac tdng. Kit qua thi nghiem dugc trinh bay d bing 2.
Bdng 2. Miii quan he giua .«5 ngdy mdi chil 100% vai sd lugng mdi thi nghiem, giica ty le cd thi mdi hi nhiim hdo lu ban ddu vai dp ddi qudng duang mdi di chuyen
STT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
So lupng m6i ; Ty le nhiim bao tif (ca the)
1000
2000
4000
ban dau (%) 10
20
10
20
10
20
Chiiu dii ong noi (cm)
100
S 6 ngay mdi j chit 1 0 0 %
10,4±1,07 \ 300 11,4±0,68 500 14,8±0,66 100 8,0±0,32 300 j 8,8±0,37 j 500 i 9,0±0,45 100 14,8±0,86 i 300 r 15,4±0,81 I 500 ! 17,4±0,68 1 100 1 9,8±0.58 300 i 10,2±0,37 500
100
11,0±0,32 i
>20 ; 300 j >20 1 500 i >20 i 100 1 11,4±0,51 300 '. 11,8±0,66 500 17,0+1,05
Ket qua tren bang 2 cho thay trir cac Id thi nghiem thir 13, 14, 15, d tat c i cac Id thi nghiem cdn lai mdi deu chet 100%) sau 20 ngiy t h i mdi nhiem bao tir nam vao dan mdi. Trong khi d Id ddi chimg mdi sdng khoe manh va boat dgng binh thudng trong suot thdi gian thi nghiem. Tir do cd the thay sd ca the mdi bi nhiem bao tir ban diu (moi danh dau do) da mang bao tir nam tir hop thi nghiem di qua dng ndi sang hop nudi lam lan truyen bao tir nam sang cac ca the mdi khac trong din mdi d hop nudi. Dan tdi ket qua la nhimg con moi dd da lam lay nhiem benh va gay chet cho c i quan the mdi till nghiem. Ket qua nay ciing cho thay bao tir M. anisopliae cd the b i m dinh tren co the mdi khi di chuyen va nhd tap linh xa hpi, bao tir tiep tuc dugc lan truyen trong quin the ciia mdi. Tuy nhien, so vdi thi nghiem phoi nhiem bao tir tryc tiep len mdi va thi nghiem lay nhiem tren dTa petri, thi sd ngay mdi chet 100% tren md hinh keo dai ban rat nhieu. So ngiy moi chet 100% d thi nghiem phai nhiem tryc tiep bao tir la 3 - 4 ngay; d thi nghiem lay nhiem Ircn dTa petri la 6 - 9 ngay, cdn d thi nghiem lay nhiem tren md hinh 1 tir 10 - 20 ngay, mac dii ty le nhiem ban diu tren md hinh cao hon ti le
PHAN II - XAY DIJNG VA BAO VE CONG TRINH.. 629
nay d thi nghiem tren dia. Nhu vay, vdi sd lugng hang trieu c i thi trong mdt td mdi d ty nhien cin phii Iiy nhiem d ty le cao ban.
3. Hiiu Iwc diet mdi mdi C. formosanus eda cdc chung MaCI vd MaC2 tdi phdn lap Mdt trong cie tieu chi ciia viec tuyen chpn cic chiing nim gay benh la hieu lyc ciia chiing phii dn dinh trong qui trinh lay nhiem [2]. Chiing tdi da tiin hanh tii phan lap cic chiing MaCl va MaC2 tir xic mdi ehit do bi phai nhilm bio tir ciia cie chiing niy de xic dinh lai hieu lyc cua cic ehimg d the he sau. Kit q u i thi nghiem tren dTa petri duge trinh b i y tren bang 3.
Bdng 3. LT50 (gia) cita cdc chimg MaCl vd MaC2 tdi phdn lap Chiing giong
MaCI MaC2
Lieu luang bio tu 5.10'
63,00 ±4,41 65,75 ± 2,42
5.10^
91,25 ±4,27 96,25 ±3,77
5.10^
134,75 ±3,63 143,00 ±5,08
5.10'
>240
>240
06i chifng
>240
>240
Sd lieu cho thay, sau khi tii phan lap, hieu lyc diet mdi ciia cic chiing MaC 1 va MaC2 k h i dn dinh, khi cho phoi nhiem bao tir eiia cic ehiing tii phin lap d cic lieu lugng khic nhau, hieu lyc diet mdi dugc the hien qua LT50 tren bang 3. Chimg td hieu lyc diet mdi cua chiing khdng thay ddi so vdi chiing gdc ban dau. Dieu nay md ra trien vpng cic the he nam va bio tir ke tiep nhau sinh ra tren xac mdi se tao nen sy lay nhiem mang tinh diy tmyen, lam cho hieu qui diet mdi se cao ban.
4. Hiiu qud diet mdi C. formosanus trong qud trinh bdo qudn bdo tir
Dinh ky mdi thing mdt lin trong qui trinh bao quin, liy bao tir xic dinh hieu qui diet mdi sau 72 gid xir ly bing dich huyen phii bao tir, vdi lieu lupng 10 /ml va lieu diing la 10ml, phoi nhiem cho 50 ca the mdi C. formosanus trong dTa petri (10 xl5cm).
Hieu qua diet mdi cua chiing MaC I trudc khi bao quan dugc xic dinh l i 67,9%, tuang ty, chiing MaC2 la 67,1 %. Kit qui xic dinh hieu lyc dinh ky sau bio quan dugc trinh bay d bang 4.
Kit qua d bang 4 cho thiy, hieu qua diet mdi ciia bio tir MaC 1 va MaC2 deu cd sy suy giim theo thdi gian bio quan trong cic dieu kien khic nhau. Miic dp suy giim hieu lyc diet mdi cua MaCl d diiu kien cit giir binh thudng la 10,1% sau 6 thing va 28,5% sau 12 thing. Miic dp suy giim hieu lyc diet mdi ciia MaCl trong dieu kien bio quin d 4''C la 2,9% v i 8,3% sau 12 thing. Cd thi thiy rd, hieu lyc diet moi ciia bao tir MaCl trong diiu kien bio quan d 4°C suy giam cham ban rit nhilu so vdi bao quin d diiu kien binh thudng. Nhu viy, Bao tu sau mdt nim bio quin d 4°C vin cd hieu qua diet mdi dip iing yeu cau sir dyng. So lieu v l mirc suy giam hieu qua diet mdi ciia bao tu chiing MaC2 trong 2 diiu kien bao quin cung tuong ty MaCl. Do dd bao quan bao tir d nhiet dp 4°C tot ban bio quan d nhiet dp thudng
Bdng 4. Hieu qud diet mdi C. formosanus Irong qud trinh bdo qudn bdo tic a cdc diiu kien khdc nhau ciia 2 chiing MaClvd MaC2
Thdi gian bao quan (thang)
1 2 3 4 5 6 7 8 9 10 11 12
Chung MaCI 25 - 30°C
67,3±0,76 67,0±0,43 66,2±0,43 64,8±0,71 60,8+0,53 57,8±0,08 56,2+0,51 53,3±0,65 50,6±0,51 47,5±0,67 43,5±0,90 39,4+0,34
Nhiet dp 4''C 67,6±0,21 67,3±0,24 66,7±0,15 65,6±0,14 65,4±0,10 65,0±0,10 64,4±0,07 63,5+0,03 62,20,12 61,6±0,15 60,4±0,20 59,6±0,31
Chung MaC2 25 - SO^C
66,8±0,24 66,6±0,24 66,1±0,20 64,8+0,70 60,5±0,42 57,6+0,16 56,0±0,45 52,9±0,50 50,3±0,42 46,9±0,55 43,5±0,31 39,4±0,32
Nhiet dp 4°C 66,8±0,15 66,6±0,26 65,7±0,15 65,4±0,22 64,6±0,25 64,0±0,29 63,4±0,12 62,3±0,18 60,9±0,22 61,5±0,32 60,3±0,14 57,3±0,24
IV. K^T LUAN
1. Chiing nim MaCl cd khi ning gay chet cho tat ci cac c i the khac trong quin the cd sd lugng tu 1000 - 4.000 ci the vdi ty Ie lay nhiem ban diu li 10 -20% sd ci thi.
Khi ning gay benh lim chet din mdi C. formosanus ciia bao tir chiing MaCl phy thudc vao ty le ca the mdi bi giy nhiem ban dau, khi ning gay chit khi xir Iy chi phim phu thupc vao khoing each giira nai giy nhiem vi nai tap tmng mdi .
2. Sau khi tii phan lap tir cic ci the mdi bi nhiem benh, hieu luc diet mdi cua cic chiing MaCl va MaC2 la dn dinh.
3. Miic dp suy giim hieu qua diet mdi cua cic chung MaCI v i MaC2 trong chi phim Metavina 90DP d diiu kien bao quin 4°C chi la 2,9% vi 8,3% sau 12 thing.
TAI LIEU THAM KHAO
