Evaluation of allethrin and tetramenthrin as larvicides against simulium damnosum S.L. in west Africa

WORLD II!:TTL,TH ORGANISA IION ONCI{ûiUIiCI :iSIS CON I'R01, i'lltlGllÂ.'J'ifi OCP INSBC'TICTI)E RIIS!]NTCII UNIT BoulffE, c0rE Drrvomlt nEl.,oR,r L7/87 EVALUATION OF ALLErIMIN AND TE'I[TA].T]!'IIMIN AS LARVICIDUS ÂGAINST SII'IULIU]'I DTU'INOSUi,i S.L. IN WT]ST ,iI''ITICA NSECTICIDES : CIIM4ICAL GROI]P FOR}IULÀTION MAI{UFACTURM : i, i,{ f ÿI ilt § Allethrin (o'rs lol4 or Plmarnin Forte) Tetrarnethrin (pl'E ,Ol5 or Neo $pamin Forte) PYRETTNOID Allettrrin = 5O g/L EC (LOT ,70061) Tetranethrin = 50: S/t W (r,w >69961) Rec tô, 29/5/86 SIN'IITOI'iO CIIE.IICAI CO'IPANY 1. Tbough testing I.1. These products were evaluated. in southern Côte d.tlvoire and eastefn Guinea against Larvae of §. danurosu'rr s.1. which are lo:own to have normal susceptibility to pyrethroid insecticides L,2. The prod.ucts were first tested. in the closed.-circuit tror:gh systeh (refer Annex I for method.). 4 different trough tests were d.one altogether and the results ÉLre presented. in Table I. Data from tests with perme,tirrin 2O/o W, are also summaxised in the same table for comparison. It can be seen that these products are much less active than permethrin, with rc50 values 10 to 20 times higher. 1Oÿo mortality was only observed with allethrin at the d.ose of O.Z ng/L-10 min and with tetramethrin at O.t5r15i/ 1-10 min. Ilowever, mortalities over 95% were achieved by allethrin at only 0.025 rng/t-tO mtn. This gave some hope that the effective d.ose in the field. might be somewhat less than the 10@26 rnortality level obsenred in the tror:ghs. 1.1. Observations mad.e dr:ring the tests indicate that like pyrethroitls in ,l general allethrin and tetramethrin provoked. strong larval reaction dqrifrg ' ,; passate of insecticid.e due to their irritant effect. This reaction began wi;ttrinll Jr-la,o tPfr .../z ) -2- 2 min. after the beginning of exposure. They also caused feeding inhib-Ltion in.lrost1arvae.Att}reendoftha}O,.rinuLeSexpoSure'ovel2Q'/ooftlie}a::rrae abt,hchif,llcrconcr'nt,ratjonsIl,.rr1:rl.roar1;7rIet,acherl.T,arvaere;rainin.qrt.l.taÔl.rr,rl, were paxal;rrzed. in distorted. positions. I'Ior.rever, sorne of these rnoribonrl'larvae i ,i recovered later '.: 1.4. Both forr.rulations rrixed easily in water, producing whibe ho.rogerie.lus l emulsions with however xrore than usual thiclç foam on bhe surl'ace. The enulsions l remained stable for several hours. 2. Non-Target tror:gh tests 2.L, Both con:pound.s were evaluaLeti fcr effect on non-target invertebrates in the gutter system (see Annex 2 fo:: details of method.). These tests were eon- ducted in the Sassandra River in southern Côte d.rlvoire. Permethrin (Coopex 2A/o û from l,rlellcome, an operational formulation) was tested in parallei at the operational dose of O. OlrJ ng/L-IO min as a stand.ard.. Three tests were carried. out. Altethrin was tested. at O.O2 and. O.O) ng/l.-10 min and. tetrameth:rin at : O.OJ ngfl--lO min as estimates of the operationaL d.ose. The results of inêivi- dual tests aïe sunnarized. in Table 2. The rneans of d.rift of the rnajoi grgupq and total d.rift are presented in Eig. L - 4. The perrnethrin values given in these figures represent means and, 95o/o confidence intervaf s for several cipera-r ,l tional perinethrin fonnulations and a considerable number of replicates. . Fi6.; 5 represents the cumulative d.rift over tinre and Fig. 5 tfre instantaneous drift over time. 2.2. Allethrin at O.OZ ngf)-LO min is generall.y less toxic than perirethrin.: At O. 05 ng/L-LO min, it produces the sanre total d.rift, but is much moreltoxio to Trichoptera and Chironomid.ae than pernethrin. In fact, it has a rnôre severe effect on Thichoptera than any other insecticide used in OCP (temephosl ch1o4- phoxim, penrethrin, and. carbosulfan). similar effects to allethrin. ft toxic than a]lethrin to EphQmeropter{r 3. River trials 3.1. River trials with allethrin were carried. out using J d.ifferent coficentra- tions slightiy less than that giving 1Oÿo in the troughs. The resultô are 2.r. Tetra;nethrin at O.O5O W/t-l.:O nin has is extrernely toxic to Ibichoptera, and. r:rore ..-/t -1- presented. in Tables ) anu A,. It is .quite clear th:rL ab bhe lower torrgori L:rationsj'i (O.Of ,,,gf ),ftOr and 0.02 r,1.ç/1/fO'), tne product has litt1e effect on ldrraaët Pro- clucing orrJ.y atrout 4ü/u rc,ducLion. r\l; (). O5 ry1ft/l'O', 9(1,/, rr',h tction j-n li,rt,,ro *,.o achieved at a well colonised. breed.ing siùe, but unfortunateJ.y this d'oiaie prqved : to be lethal to fish. Soon after spraying several fish were traui{r;ltiSed lnd.: completely disoriented. S;ral-l-cr fish d.ied as a clirect efi'ect of ttre la*vic.i-de.li 1.2. per,rrethrin Coopex 2ü)/o Ifr actua1.l;; used in the Pro,qrarnrre has an dfrfective fie1cl close of 0.015 n,g/t/tOr giving 10C06 re<luction at that do:;e witlr rto lf ish, mortality. In the cond.itions of the trials of allethrin, it would be to give IO0zd effect over 50Om. 1.1, Due to the toxicity seen with allethrin, and. the lower activity; compound, no river trials were done with tetramethrin. 4. Conclusion Because of their relatively lovr activity against S. darnnosun (in of pyrethroid.s) and. their high toxicity to non-target invertebrates ( at least for alletfrrin) fr:rther develop,'nent of allethrin and. tetrametiu Simulium larvicides is not envisanEed. I e*pèctedri; i the ,l arrâ. I i" i 'Lhe class Il; fish r l as Bouaké t /rc/at D P I{ B Kurtak Renaud 0cran lÿah1e I 1 I I i I I I I I ir rl :, '-J:p,dIJ .P: l-t, ': ,l ,i .l i' tt ' r-J oIJ c-l c)|f a a C)OU L,.t --q---------- U)tlÉr irj F< o lrl 'N l,r(J) HË(n or{ Fl o EÈ r-3lri aHa Ç) H U)É lcol! lèlFr I l-{ lfl IrJ IE tâlola IE !, F HÈ tstr rl o a ul o§ 2t o :(a o\,.l\, E|-l E H E rÉo âJ;Ë E H r1uÉHo rd olrj F ë 0q, H' Ho a- xE o @ E o 3G.& E +§>ts O^EI Ho r.o(n ô B§>HI oz*no I I c+PZo0roI'H ci- <oppo olsl_-t--------lplo IFJI t\)lLnl___--_--lo loI r\)IunI-------- Iloloi\n o H o t\) o \rr bp, o o o ;. 5 cf'o l-J I t------- P.i,p o5 oq P.I cf cf o a Çt- a lJ r(J lr. o'-l t' cF5 H fD(DI' FI .t "E'Ê\}J P.{F-15oo 8,:r.PO \,.Jo +. \, vo\I tu ,§{è \rl {-l O\ H I l------------ Pvr@ t§§ -: I o§ o\ \o oo o\ \o @ o\ \o\o \,l Hoo ^oloo \o ^Olo 1§ EÉF]E@ @ @ o§o\ o\ o\ o\ttrl§§\x\o§ or.rr \,t§è -l § § tJ r.l r:'i f--J oo(D(D cl- l-J O cl- cl-lB5 (D 'r,fuo <5§o\N PCFo\ Biÿ\t) P. lJ\D5P.O\5P lJ ^c) 'tJ|,.r5 0 (Dutoot-Jô H'd r'i5 oovOX(+ o5ËHtc, P.0, E' I P @I§P ----;----'l S ts O\}J\n \rlÀ F] t-- r§ --I f§§ -l f\)q\ -t -J('\H-l -l\n r§ I H\rr @|HH\rl o I H @ H ------§ ----''l -ll.l v.l I @ o\ \o \o lo\x I. .loO\ lO§ l-.-----------{ H Ele ü[§ oo L-----------.,1 Hlool.ololN o oH t o^o .O. oOo\n oooo oo 1§ oo t§ -----J----- -lo^olo 8N\o Ê @o\ I Êco§ o\ \, \,I \N§H@ N)l\) -l \o -:§ t-- \0\o t§ t- I o\ \o\o Hoo ------------l tt tl tl o oHH o I5 ooo.HOO\Ot§ \rl o o\o§ o o \/ cl H @q\ I o\ Éo o\ I Po E @o\ Ièo F3 @ o\ I .l.- .§ §\N\o§ ^^^U.j IÙ H v\-rv hooçjcJru55c,' 0q(,, c)oPo5§ür(+Hcl r(H tDoIJ,OP o(r- a :.1oHofJ i,. Hocqcl-(,! § s,OctH5PP.O<ct' cFdc{oI FJ P.OH(/) . cÈ 2 5'loa OOtsr)oo)-hJHP' cl-cq ts. v'r)'doH\N cl-O§o\- \}Jpo P \.l.lHl7l o 4 P. \r.'I.6' s. FJ 'dbHOo l-J clÊ)tJctO HOE5(D ctr E. aC) BHÉHo a l Eo Lr)g H o r-lc)(D !l rJ lu hr cF E =---------- fuble 2. Elfects o{ verious pyrethroid coopounds on the 0iJor non-target aquattc invertebrates. Version Date: 2ïllllgl llest Nuaber NT-86-5 NT-86-5 NI-86-É }lT-86-t },|T-87-7 NT-87-7 NI-87-7: I ! ------------ -i--'r--: I lDate 5-6/I/86 5-6/l/86 l3-t4/I/86 t3-11/I/86 }4-?SlullllÊ7 z1-?Stvllllgl 21-25/vlill/87: ! I ------------ '------------- -:--.1--- ! I lnrecticide: ! Cheli crl Nroe !0!lS Nurber ! Trrde Nale ! Conc en tr rt i on ! Dosrge ! (rg/l/10 rnl rl Iethrin gerlethrin J03r 1821 Pynrli n Forte Cooper 5T EC 2OT EC 0.020 0.015 rllethrin 3031 Pynrnin Forte 5T EC 0.020 peraethrin ellethrin tetrroethrln l82r 303{ J035 Cooper Pynarin Forte Neo-Pynrain Forte 20I EC 5r EC 5I tC 0.015 0.050 0.050 Prrrl r 82l Coop ei !h, Irn I 20t E 0.0ls I g I lI Adjusted Dri(t: Eph eleropt err ??.r. 93.0 54.3 83.5 77,5 89.2 34.2 5è.9 5À.0 41.0 79.8 74.? lChironolidre 2t,4 32.4 34. I 44. { 38.6 36. I lTotrl 32.5 83.9 {8.5 72,1 59.5 55.8 : 5$,3 | lPerk I ; I ! Instrntaneous 37,9 40.8 ; tS. Z t lDrilt ; ! ---i---+-.- t lTire ol Perk I I lDri{tefter 15 tS i iSOt IlTrertrent(rn) i I I r ------------ ---i---- I !Length of I Catostr oph i c lE{{ect (h) i choptera t{. si tlr, r.75 2i 232,0 !------------i'--r'-'-l lLength of I ! lReversion 20 0 i 20 I !E{{ect (h) : ! 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Onoe a treafuent polnt has been chosen ln ttre partlcular stæetch of the. ,tt== Ito be usêd, the amorurt of foruulation requlred to gÈve ttre deslred concehtl"atLon for 10 utnutee of rlver ùtschaæge ls cal,qrlated. It ls uflÊIl.y d{Luted trtth a i,I consenLent a.moutt of river rater Just before appllcatlon ltrle aottral applloatloir ray be calrrled. out rlth a tra,nd. p:3oêsure Erprayêr such as ttre Eud.son X".perrt 1" tt i, case of malL gbee,ms. A boat qpd a pleroed. dr:n my also be uEed. In these tvoj @.§es, the rppllcatlon oan be tlned. to last 10 ntnutes. &ê appllcatlon 'oah afsb te done from t'he aLr uslng a heLlcopter. trhon ttre alrl the lnseçtlolde tnêy ber pourêd. t,trrgurdaanouüLetlnthesl.d'eoftàenach1ne'otsprayed'1ntother1veruernsthe equlpment used in routlne'opêratlons, ' : ,l Aerlal app).laatlon is egsentially lnstarâtzneous, but ttre applloetlon ls naêe J'n sIorl,y-rnorrlng reter soroe ùlsta,nce abore t]re'ft::st rraplds ln euch a vay that lnsectLcld.e front spræds out to give a longer erposure ln the raplds. EnalrratLon of the effect of ttre cherulca.l on ths larral stagp of the veotoq le æ,mLed. ort 24 houre or 48 hor:r's after applicatlon. llhe uhole portLon of rlver iLs a€ain artrreyed. by hellcopter and. the proportlon of Ia:rrae rrhI'ch have d.etaohed. is ,, eetimateü . i . I I I I I ) I I I I the: I i i I I I 4,. , ANND(; 2 MEIIHODS.ÔF EVÀIU.ILTIOT{ OF TIIE DFFDCTS OF SIMULIUM IÂRWCIDES AGA]NST TTO{-TÂITGET ORG/NISI'IS GUTI'EI This technique is based. on the meâsurerncnt of the drift (aetgctr- : ment) of benthlc aquatic organism. This phenomenon occtrrs naturally In: a d.atIy cycIe, but is very rmrch increased. by the passags of toxic matà- riars. ; The gutter (a seotion of H/C pipe 2rn long by 12cm j.n d.iameter) represents a stretch of river ln minLatrrre. ft is placeit in the river 2{ hor.rrs before the appltcation of insècticide'andl colonized. by anai.ng i natr:rar supports (sÈpnes, g?ass, etc.) rvith atlhering organlsms. rt; Lp ; usually placetl a few hund.reil metres below the point of appllcation bfi ; the lnsectLcide. . : t;i IA nêf,'lrtlttâched to the d.otmstrearn encl of the gutter, antl ae.Ugfiio!; organlsms aæe collecteil àt inte:rrals after the passage of, the fnsectfiihe!, :.1.:. This methoil thus pereits an analysiq-qf the clyna'nics of the effêdts of the insecttcides, as well as the global reèuction,of each group: of..: orga^nisrns. . : ,l "r,i,.: li' 1,,i, tq ). "{t.':' ËrF,,:' ffii .â'l'r "' 'JÈ-.lri'', .:,fü:i ," ''*.r'.:: 1r I i' i, 1 ::l trl ,rl lr; ri ' Itl ill ll i'i i,'i rl,lr, rl r ilr l,ljit Ilti li, 1,, ';i i:i ::i irtlrl lrl Lr I I :it.l , ) SIMI'I,IUM IÂRVICIDIT SCR]IEITntrG nI THN :ffi-crncr^srs collTRor, InoGIr ttflt ÀT'rNü( lJ ISjlgL: Clorrd-clroult trough trrt Thtt rrthod rrr dcvaiopcd for OCP in Àfrica by Dr. H. Jeoaback brt.d on r ryrtcr ühi i I I I bh I }lr.R.0augIrrut.drlt.D!lvrIy1nNryIorkSùltr.IthrrbcrnlurÙhrrrodlf1rdbythr0CPIa|cc[lcldr ir,rrch tttr, Lorr. logo. Lrrvao ooll.cù.d ln lhr ftrld rrr ollovrd to ettroir th.rt.lY.t On r r.!ovrbl, i platr lylng la thc bottor of r trough vhrrr satcr ls roclrculatcd vtth r putP. thr plrtr ls lLhon trpnr- i frrrod to r r.coDd trough vharr lnsrctlcldr hes elrcrdy becn alrcd lnto thc rrcirculatlng Yft.f. lfttr r 'l sprclflc .rpoturt tlrr, thr plrtr lr flnally oorte.llüy 1r notrd eftrr 2'l hourt. Tcchnlcal dctall r ' Tho trought urcd rrr constructad of aluolniua and palnted vbltr. Thc troughr arcisOl cr lorg, .: l5clv1drrad8crdorp.1hcyerac]'osrdatonccnd.ltthcothcrtnd,econstrlctcdlrct1o|norIi]p, I! cr lorg, 8.8 cr v1dr, rnd 2 ca drcp ls attâchod. A rcaovablr ratal platr rcsts ln thc botior of tnlr .l ,l Ilp. tJetar 1s puupcd tato thc closcd ead of tbc trough and flovs ovcr thc plrtr in thc llp lqto e rqscrvol,r to bc rrplretrd by thr purp rgalt. SoaII elcctric ceatrifugrl pulpr vlth r dlrchergc of ebout, 22 l/àtr,. rrtp urod, ud tbr vrloolty orcr th. ottachlcnt plrtr ls about Orh/rcc. For th. attachrcnt andlolsrrvrt{on syrtratr. tho rrsrrvol.r ls e plaatlc vastc-buckct hottllng about 60 lltrar. for thr.rpolure'rfctcr, ri l0 I l1tro rneqrlufra pot 1r urrd rr l rcs.rvolr to raducr tha rEount of lnrrctlcldc ncadcd. Rlvrl urtcrllr utid et r1l rtrgb! for routlac trstr. Ita cbarecteristlca (tcrpcrrturc, pB, turbldtty) rrr carc.fulrly not6d. i Lçreç arc ooll.ot.d by rerovlrrg thclr naturrl rupportr fror th. rlvcr. thay rrc t{ansporfctt la ] plettlc brtr h ra lorbor. Crrr lo tokcn to roparet! thc larver fror the lcc by e laycr of fricrh I.àv.! o.r grrr!. Although thr rqulprcat can br urrd aù tha rivrrrtdr urlng e porteblr clrctrlc gcn.rêtdr, thlr typr l of tcrt lr urually doac la a lrboratory vhlch uay bc et sorr distrncr fror thr oolloctlDg pofdt., ; I ,: . thr :laJvac naturallÿ lrava thr vcgctetloa-to rcrk r strougrr currcnt and thur tttach to thr plrtr ln thr llp, vtrtcli har tira : ,I hlghrrt vrloolty la tbo trough. tha larvea arc lcft for zil hourr to.Dtur. llrr ettrchrra!. tlarvrr'uhtchl puprt. durlug. thlr prrlod rrr rllrlnatcd Just bcforc rrpolur!. thr plrtr urually coatrlD! i.bîut 1001 raturd lrrvrr end trrorrl huadrrd young lervrc. i ' : .t. llrr lrrvlcldr forruletlon! ar. approprlataly dilut,ed ylth rtisttllcd vatrr fucaiitciy ptiot to : i thr tart. Thc quanttty Dccrlrary for tha lovcst concantratlon 1r rddad, by plpcttc to thr rcslrvoir of'thci .xposur. trough vlth thr puop runntng. Thc inccctieide ls allovcd to clrculet. for ! olnuicsi to oUtpfn a ,-l unlfora dlrprrrrl. lddttloael larrcticidc le addcd to tho leEc Jy!t.! üo obtaln thr hlghcr cpnientrationr' ln e trrt rrrl,rr. I ;l, lbr plrta fror tha rttachEant trough Is nov carcfully llftctt out rDd plrced in thc frposurr trouih for r dcflncd prrlod, uaually I0 rlnuter. .t of the, trough.\ Larvec drtrchlng durlng tha axposurc perlod are crugbt ln e nat ettachêd to tha lip Âfttr thc rrporurr parlod the plaüa and tha nst rr. t,rrnafrrrcd to a holdlng troughl lt tàe enÇ. of r 2l-hour obt.rvatlon prrlod, tha dctachcd larvac ln tha nct, rr vrll ar tny dcad onrs §ti[I attacliad ti thr plqtr rr. pr.t.rÿ.d la rlcohol for countlng. (f ftrst collrctlon lc uruelly tûa 2 hourrl aftcr rrposüic rlnor rott lrrver drtrch la thlr prrlod and thc l.rÿt...y d.oolpoto lf lrfù too lond). ftr S,tvtn6ilrrvlpl rrr klll,rd ytth bot vrtrr rad r1!o p!...rvcd ln alcohol for countlrg. lotrl aurbcr crporcd, I itred, rrr rstrbllrhrd r.purt.ly for raturr (6tb-?th lnrtrr) ud young (frt-5ttr lnrtar) f.rt1L orpotrd to lartctlcldr rü pupatlng durlng thc tcst arr not couatcd rrcrpt for thc ooatrol uln]c lncludcd la thr lurbcr rurvlvlag. l ltlng,. ard i :,rl:thc urual conforratlon of a t?st is a rangc of ! conccntrrtlon! and an unt4ortcd cQntrol vlùh tvo rcpllcatar et rrch oouccntretlon. Pcrccnt EortÀIity is crlculrtcd aü oach conccntrrtlon and cônccn- trnnrfrrrod lo r thtrd lrough rlth ollan reLrrivhfrr lhr: hc ahd . Larvrr rc ùhcy trc { Ç trrtion/rorteli,!y llnrr cctebllshad by probit 8naly!is. I I I I I I I i I I i I