Rearing and colonization of Simulium damnosum complex and related investigation: June to December, 1981

at 'IYHO O;{CHOCERCIAS]S COI{]ROL PROGRA&IME RESE.ARCH REPORTING. Reanine .and colonizatlon, of Simuli.ug d.amno.sum complex and related investlqationg. rfiJo/ocP. J.IT. Raybould.. 1st. January , 1982. June - December, 1981. Sub j ec t: Institution: Personnel: Date of submlsslon: Perlod covered.: liigtature of responsible officer: C. ./ -.( .:'::.t/r.14 CONTENTS. A. INTRODUCTIO]{ AND SU"}4ARY. B. REART}IG .STD COLONIZATION STUDIES. STUDIES ON EGG BIOLOGY. LIGHT TRJP COI,I,ECTIONS OF OVIPOSTTING S. .SQUA1,,1OSUM. VISTTING RESEARCII,;y'ORKERS. PUBLICATIONS. VTSITS TO RESEARCi TNSTITUTES AND ilIEETINGS. EDUCATIOITAL ACT TVIT]ES . WORK PLAI\Ti\TED FOR . NEXT QUARTER, AC K]$O'IfI,EDGET.,E NT S . REFERE}TCES. TABLES. . 1. Identification of a laboratory taatlng form of S. {aInrr_osrJn1 s .1. 2. Laboratory colonizaticn of the ,tJ-spot form?t of S. soubrense/Sgqg_lipguli . 3. A comparlson of two methodsof inducing ovlposition. 4. Single egg batch rearing of the ]-spot form ofS. soubrense/sanctlpauli. INSECTICIDE SUSCEPTIBILITY TESTS. 1 . Current investlgations. 2. Presentation of earlier work. r,aBoRATcRY STIJDTES oN vrIrNG-TirFT coLouRATroN rlT S. sa STIiDIES O}I TI{E ECIOSION OF S. DA',NtOSi.rr COI'IPE&T SPrc IEi D l ; G H I J K L a a I a a , a a o SIJiVi a tL 2 ]NTRODUCTIO}I AI{D S.UE$IARYA a The major. developmslt,ltrring the past six months has been the ldentification of a laboratory mating fori:r. in the S. osum compl-ex and the successf .1 col-oni-zation of thls forr-r at Aicoso'tibo. This has been achieved. using the simple rearit-ig technio-ues developed for use by O,C.P, Colonization has bee.: faci'l-iLated by the use of an oviposit ion inducement techniqu.e receluy oeveloped in the U.S.A., whlch gives higher rates of egg develop,:ent than earl-ier .rnethods. Unlil:e other Y7est Afrj-can members of the S. d.annosur.m eomplex, the colonized form (uhich is close to S. soqbre4ge and S. sanct-Lpauli) mates read-i-Iy ln the laboratory but : s difficuJ.t to blood-feed.. Further feeding uiork is therefore enr,'isaged-. Insecticide susceptibility tests have coatinued to be carriec'i out by a colleague 1n V.R.A. In spite of a paucity of materlal in some areas, good progress has been mad.e, especially in southern Togo. Inve stig ations on the eclosion of S. dantrosum coritillex species, egg biologythe wlne- t'.ift colouration of S. squamcsum anC on the of E- da;ry1ogufii g .1. have contlnr'.eiL to progress. Ilght trap col1ectlor.,s of ovipositing f e-rales have given interestlng resu,1ts. Tiro papers have been prepared a:rd- presente -. Important vriork has been carried. out at Akcsombo by visiting consul tan ts . For baclcgroui:.d. inJ'or-,iation on scne of the on-golng studies descrlbed 1n tl,is report and tire investigators concerned-, reference should. be macje to n1y earlier reports. Bz REAF. IIG 4"\D COLON]ZAT ION STIIDIES 1 Ide .a tlf ic. t ion ofa I atlora tor, rr ma L NEI f orm of S^ di suln s-I The inajor baruier to the laboratory col-onizatlon of ,,/est Afrlcan0,Lchocerciasis vectors has been raating. rvhen raboratory mating by a t,terrlber of tite S : a,^onoswn comrlex occl;rs, therefore, ldentif i ccrtion of the s-,,:cies oi. I'o:nrt eoncerned 1s iinportant. si"ii::cns a:rcL Edman (rggric) re;ently established the flrst raultiplc gcncration colonlr of S. da ilios,:iln s.1. ir.ith matenlal from the seachl rRapids, in tlie vo-i ta RJ-vr;r., ircar Aicosorbo. The form eolor:ized .,ras nct cytoi:-pec1, blrt adul i:,s ri-,rei.e keyed. out to el11ier S- si banuin or s. da^,nosrnr s. str. bo.scd. on the red.ucecl scutal pattern (Oang and Pe terson, 19BO ) . pre served male s were re-€x&r"1ined by Dr. Gaams and ifentified as a distinct of the rnaf s g subseq'-rently form of S soubre sanetipau.li in which the males have an extremely reduced t'5-spot" scutal pattern. A detailcd aceount of tili s f orm, incl-urding its l,lereclitir et al referred to as chronro soinal (t esz ), rn the J-spot eharacteristies, has been prepared, by the present r€lrort it wi 1I si@1y be fcr'-r of S br.ens Lt au.li a rn vlev'r of the importance of identiflca.tion of laboratory nating iorrns of S. damnos Lrn .s .1 . , c onf inl at ion tJ..-,t the j-spot form mates in captivity vvas deemed iesirable. During the visit of I'ir. K.R. Si:',imons fro"l the Uitiver.sity of i\lassachusetts , dfl atternpt was rnade to obtain such confir,nation in col1aboratlon wlth him. This also offered the oDportr-mity for mc to l-earn soile of hlg nelv techniques. An effort l',as rrr.ade, therefor.e, to incuce laboratory emerged. adrilts, believed. to be of the J_spot formr to mate in captivlty and to rear F1 larvae and adr',lts for eytorogical and morphological iclen tif ication respect iveIy. a 4Puoae v/ere obtained (i.;-th the help of Dr. Garns) from a breed:-ng-site at tsdgba Rar:iCsr oh the [iono Iliver, bord.ering Togo and Benin. Larvae were alsc collected and cytot pedx as 85% 3-spot fcnm and 151a d a",,.to SU;t s.str.D The pupae .JCre ,.r-it i;rto a cage in uhich emerged ad.ults rere attractect bl- light into a col-lectii:g t'rbe, ,;here b,e,rr ir,rere observed. for ma.tlng behavi-our. 96% of i,he mal-r:s t,'cre morphologically identified as the J-spot forn. Adr''1ts of both rexes were suckecl lirto aspirators and Lr.lanipulated by .ro;th to agllregatr tl'_ei'l and encourage mating ( Si rmcns and Eci nair, 1981b ) . Fo]low:nr, this breatrnen t, the flies ui/ere stored in speciall;y deslpmed 'lnru,ting-":agestt. Soon af ter enprgence ntales mad-e vlgoro'urs ,11s,,i1ts tc inate hut the fei:ra1es were refractory and ritany a-ternpted matings failed.. lflhen rnatlng vras slr.ccessfully completed, the seq,-,.ence was the same as that observed by Sii,rmons and Edrnan (f ggf U) 1n Lhcir Ia'bor.atory colony. The cLay after emergence the fe;,la1e s were of-fc:r.ed. a blood-meaI on man. 31ood-fecl flies were r.mintained in single tu,.bes. Three days l ater tJre;' lvere induced to ovlposit in the evenlng by Lhe Si.u"nons and Ediran (tg8tU) technique. Thirtee.-r. fc,,ales laid e,rjs arrd allo,-,t slx of the egg batches were t-ertile. F1 lai'vae y/erc reared in on-e of t,le rearing systems at Aicosornbo (Rayboulc.. et al . c i9S?). La.te 1ne tar l-arvae ,vere fixed in Carnoyts sof u.tion .,nd cytotaxono:ricaI1;; 1d-e:tifled as the J-spot forn. Lar.ral oeveloi:-ient li,/as satisf actor,.; but pupal mortality .,as high. However, the rclati-veIy fevl ad-'.,f-ts obtained exhibited a very high ]aboratory m:tlng rate. The mal.es ,-,ere moryhologicaII;r identlfled as the J-snot for.'r by Dn. R.A. cheke, although their scutal patterns whowed more rrariation than is ssr-r.aI jrr field collections. It All cytotaxonornie lrfentifications v/erc. earried out by Dr. S.E.O. I{eredlth and l[r. G. Fiasorgbor. RIt may be conclucred iltat the J-sp of {'orr.t of S scubl"ens sanr: ti paL.-Ii m..le s in the laboratory and that this Lvas tl e f o;'m coloni ze-d l;,J Si-rmoiis and Edman (f gaf U ). Thls c;Jhotype represents the se c cnd ,;r6.-j ,1ilJer of t he S . C f.i'.inosum c o,rpf ex, e.nd the f i::st vector of 0. volvtil-i:s, t,o be ictentifiecl as a Lar-,r>t:atory inating form. It ls al-so tire onlir nleY-ilcr of ti-:.e col1pleX fo::' rhich a lairo:ratory colony has been e s t' .bli shr: d . 'rhenerre:' f abor ator;r nrat,ing activit;- by ,,rest Afric;-:n S d.amnosum s.l. ha,': beeii obserr/ed., ':h.c ma] es harre l-;eerr vcrJ" a.ctive and. the females refrac tcr.i,' as ret-lor t ed. h,:r: ( Fa.-r|6U16 , t979; GrUnelvalcl, p CrS Co-:i11. i Cupp et aI., l9B1 , Si.r"nons a'ad Ed.man, I981b). This simllarit;r of behaviour rrrorcpts the o-uesticn whether all the carlier reports also referred to the J-spot forr.r vrhj-ch wor-.Jd" not then ha./e been di st ingu lshcd fron S. Eo brense s.str. Thus the present findings cast doubt on the earlier recogrition of the latter as a laboratcr,.v mating specles. rt l','ould be 1n l;eresting to icnoly whether it i,/as tr€ J-sr:ot forn tne t Cupp et al-. (f gSf ) reared f,or a comitlete generatlon. ?itis i'iork has a1r'eady been preparecl for p,-iblication (S1,t,1.-,ns et 2]., 1?82). 2 bor.a coIonl ;zat t the rr -sno t rm" fS sanctinaurll. Thc ioentification of Lh. 3-spot for,l of S. soubrense,/ sanc tlpauli as the laltoratorJr riating f orrn that t', as ter.r1:oraril;,' c'rlonizei in Lhc USA (Sl mons e.i:d Edr,ran ll8lb and section Bl above) suggested that it eould be c ol-onlzed at Akcs or-,bo. This ob jecti ve v/as achieved ]arge1.1r thrr:ugh tiie effolt of .',r. D. Boakye who carried out tlie rcutine lat'roratorJr vuori<. Tr:o eolonies of the j-snot for,-r have bow bcen establiehed at Akosoi:nbo. The f irst v;,as startecl ,'rii;r a s Lrgte female collected .on 5lB/g/U froic neal' Kaboua i-n ?enirr. This f1.1- was blooci-ied a-v 41.oso1i.i:o anc l- a"j-C abL;ut l+47 e::gs, almost al-l- of 'r;h ich 'i/ere fert j-1e. TI^e Lai". ae: deveJ-opr.;6 e)it1'enelJ/ ',,e11 UntiI a po'i/er i'aj-lure kil-led. all- Llrose that ]rad 'rot already pupated. ldel'er-tirele ss, the puJae surrrivcd. and 19t a.d.'.,]trr r,,rcre obtained.. T.r.e matinil r-a,tc of' 1, ,3 F1 acru--]-ts lrrras v,:rJ,/ hi:41 (a.Iniost every fe,.rral-e coul-c'l- be indivi;,rl,ualIy ,^nated- in a sma]1 aspirator") but felv f e,,la.1c s took bl-ood ai-rd only one batc-rr of f :r ti1e F2 cf ..s r,,;as succcssfully rearecl. -he felv F, ad,r-rl-ts obtained. shoi,vecl an unbalanced. SeX ratio vu,.ith 22 f.e^._-l-es an,C. o:Jy a0 males ernerging. A behavioUral cherrye 1/ri as .:.1 so a,^ltarent: rrlol t ra]- es ignor.ed, tfie fema]-es v',hi]e the l-atter exhibited aggressive 'tsting behaviour. Ilo'wever, two females Y/ere successfully mated (probably both by the sarire male) and a single fertlle batch 'ras reared to F3 ad.ults. Only 12 fe -ral-es and 10 ma.1es were obtai.ned but a.s the se)i ratlo and the aggressive mating behaviour of the ii:.Ies were agaiu nornral e successf uI matings v/ere achie./ed. Once a;4ain feeCing proved to be the major Cifficulty and onI;r eyls fertile egg batcli was ootaine,l. Only 9 Fh adults (6 fernales aud J nrafes) lvere rearecl and, J of tite fenal-es er,lerged after all the mal-es hao died. Nevertheless a fcrtile egg batch iras obtaine d and. about 369 eggs developed. The F, l_a.rva.e are develo.ping wel1. This tln;r colon-.r is of p;rtic ular interest because (tr}, chance ratl'rer than deslgn) it has been subjected to extre.ne inbreedlng. Thls mlt-st maxir"irise the cfiance of defects, such as an al-tered sex ratio, res:l-ting from inbreeding clepression (Sllraons and Ed.man, 1981b). If the coIor,.y conti-nues to survive in spite of intense lnbrcedlng, therefore, it uvoul-d suggest th-.t loss of viabili-ty is iiot inevitable under such condltions. The colony is therefore valuable as an indica.,or of the f'easi'-.i]it;r of long-terrn colonization of the J-spot form of S. so,"brense/salc . -7 - ri second. colony of the J-spot forrn has recently been established. at Akoso:nbo. It was started. with material fror.r B6gba Rapid.s in the i'lono River, on the :tog:o/-tien-in bord.er. Several laboratory emergecl females were successful1y induced. to mate, to blood.-feed. and. to Iay fertile eggs. Once again blood.-feedingr not ruatinge vras the l-iieiting factor. Tkr-is colony was started. on a larger scale than ti:at from Kaboua and. numexous F1 adults axe emerging at lhc time of writing. They are, however, proving to be exceptionall. &ifficult to b1ood.-feed., 2)c A eomnarison of tlro method.s of inducinE orri posl tion. Th:is investigation is being ca-.ried out in collaboration with l,tr. Dari-iel Boakye. Lewis et a1. (tget) induced gavid Lj3gggJ =.1. to ovipo- sit by immersing: them in water j-n a b;be. r\lternative techniques have recently been developed. j-n the U,S.r!. and used. successfully with S. d.ecorum (Brenner et al-., 19BO; Sirmons and Ed-ma:: 1!81 a) and Er--darg o"u, s.1. (O*pp et a1 ,, L9B7; Sii'rnons and. trdman 1981 b). A major problem in the lacorator"r colonlzation of S. da.mnosum s .1. l is that many eggs laid. in captirrifir fa.r-l to d-evelop. Egg d.evelopment was therefore compared using tuo &iffe:ent methods of inducing orri- position; the Simnons and Ed.nan (f9gf b) technique (refemed to below as the I'twilight nethod.ti) a;rd- tirc i:ru-nersion method. (Lewis et a1. 1951). 'Ihe forner j-nvolved- the prorrision of oviposition substrates, agitated. wate:! and conditj-ons of sirn:la ed twiright. 3ecamse of the special light con&itions requi.red., the twilight method. was tested. in the evenjng after d.ark. '-Ihe inmersion l,echnique was tested. both in the evening ancl during the day. S. .s_gua.gq.glg fenaJes from tsatsadu Falls were used- in these investigations" BResr-i1ts to ciate are gi';en jj1 Tables 1 , 2 and i. Al-though var.i:,tlon betl',een i.ndivioual- esig-batches is very grea+., it -"ra; be seen -bhat tr.e .lg devel-op:reat rate of 75% obtained usint the tl;ilight rnethoC is nia r'1y tv;icc -i,hat obtainecl ';,ith the iir,nersion tecLurlquc. Results rur th t'i ': 1:.r.tter n,:tlioo lrere 367i aevelopnen t when sti-rrrul-ated. at rrigi-i, anc-l isJo/c titr:YL imerscd. d-urring the da7 . A1thoui5fl the twilir,]rt [ethrd gives ]ri6 her rates of esg devel-oprnr-.nt, it i-s lesS sr-:ita'lIe for obtain tr€i indlrrlr-1'''aI egg batchi s .i'r.)-a partiteular .ie,r;..Ies beeause the fl-ies are stimulated- toge tl'i e r rrthe r ti-ra:r in separa te tube s . Ti,e r,reblcd- of Brei:rncr et a]. (t 98O) f,as not yet been compared wiih tlre o l.jrcr technlqu-,:s, but it operates on tire sanle prlnciples as the Si rmons and Eflnalt m€rtltod a.nd -rlght be expected. to give si'^tiIar re su1 ts . 4. Sin ee b:r tch re arin s of tfe of forni of sal'ictiPau-1-i . A nu:aber of egg batclies of lhe J-spot for: ]rave beerr i'eared. separatelT aai the Iar,vae ancl female parents ;lsed for chromosomal and morpholo.,ical St'ldi es reri,)eclirrely. It is hoped. that this v'lork v,r1It assist Drs. Gar,1s, ,.ered j.ti and- Cheltc ( consultants to O.C.P. ) to build ui: a, pictu,-re of the :-.elatlons.r ip bctlveeii certa.in cjrroi:rosomal and. morpholcl;i-c-il charactcrs. 5. Cro s s-matinf, at tei:t"ilts. The J-s:rot for,i of S. soubrense,/sanctipauli 1s aJf exceptionally sma]I rne',lcer of t,he S. da,',moslm co'rp1e:1. Attenrpts to cross the males of tltis for:n v'rith f e,,ra1e s of S. sq:-r.a-'rosrjrc arpanen tly fa.i1 ed be eEEse the fema'l es were refr.ac +uo11 ;r. Althouigh the J-s rot tla.les mad.e repeated. r?heroicrr attempts at matinga, Lliey were knoek_ed- asicle, bouiled.-over or trarnpled on by the mucli large:" sqLr-allroslxn f ernale s . It s.e ^s porjsj-ble spccie s arc re ,..r-r";,1 y the crO S S-r'rlatin ir' a t+"e,:fi:t S . c. Ii.SECT I0 IDJ cJSCEPTItsiLIT Y TESTS -9 th,a t i-f sn'EI 1e r f emal-e s of l-ile o the r 3-s'nt ma.les might sr.lcceed in tirci r I C',rrr., i-it lnve s t ir. a. t :i-r-rtr s . Lile ,).-:T.:e,,,l]i:.t be *r,',,cell O.C.P. alLd V.-R..A. for I'tr. Acllariiah and' an. e.SSlS1.a-J-r-.,., to .i,J Sl-iSCei)-r,it,111ty teStS in the I/O1ta Region and Kitrtari.-ro, altca ctf Ghana, has i"ecentl;r b':en eXtend-ed. to i.iclude sor.thern Icr,.ro. T] is ;/olrj, h,"s continued. tc be rrnd-er my 1o':a1 s,-r.per\risir-,l-r,i-rti-r technical- -Lr:tai1s belng; checked by Dr. D.C. Kurtak. -r-ests i;r tjrr-, rrar lcus areas have been carried oUt 'rhen adequate materlal- h:s bcco,1e ava i-l-e":l-c. fn tl.e Kintampo area, tests rrrith ter,ephos have l-reen d.one mostly on olcl llirvcre from Yab::aso cn the Oyoko River, i':anso on the Ta:rfl Rlver and Yaya Crossrlfi o;h the Yaya River. Further tests with youJt3 larvae are requirecl.. uttor], 1n the Asr.tbencie Rlver systern vrrill- coltunelice vllren the rrva+-er leriel r'eeedes el.t'oLr!,]L f'or larvae to be collected-. i,Tr:ch tine has been -s.)ent fruitlessly searching f or larvae 1n the Asui,avrkaw Rlvcr system sinee t;1e experinental.:-treatnents in JUne and .fuly. lior,:rg.7c'1', a. cliagnostic test vias carrieC out at Djoclji on tjte Gbarn-iioua Ri.rer on 22nd. October and. a test vrith young larvae 1"/as canllr:tccl aI Asu]..awkaw Bridge in mid-December. llore ra-]ici pl:.ogretjs i:as been ma,Le 1n scutlter"n Togo vuhere more material nas ')ee;L ava.ila1c1e. Larvac fro,ir the loivcr l,iono River have been test,ed, l; itir teme.:lLos (Z tests on old larvae conrpleted so f ar) and me thoxyclrlor (t tcst on ol-d 1e^rvae) . In the p1-ateau area, diegrrqstie--, t,ests vrrtr tentephos haire beeu carried out at Ayagba on the Cba;r-lloua Rivere Arnou-Oblo on the Amou and Azafie on the River - 10 - Goirobe'. Four co::.pIr,.te teire phos tests on you-ni.. Larvae ancl ttruro on old har.re hr:en co,l---] eter-t at Ayagba. tsoth yorJng and o1d, larvae fro,-' tl--r: Slo Ri.rzep, r^L06r. PaI1me, have also been tested v,iith temephoS. f t is antlcipatccl t]'a t the programltle agreed to so far, w111 be ncarly eom,:l etcd by tjre end of the ycar. 2. Pre sentat e ag1 i :r' '' ork. Earl- ier r o']r Iiiver itear AkosonlLo on larvae fro,'i the Sc-nclii Rapid.s in the Volta (see previous rei:ort) has b:eri analys.c and presentctl :'or p!)ssi]-.le aistriltution ( s"" scctionl). as a ,T.iC nrimeographred d.ocumqrt D LAPORAT ORY STTJDISS OIT 'I/IIIG-TUFT COLOUzu\TiOII N, S. SQUA,]{OST]1\,1 This woril is be ng dcne jn eollaborat r-L)n vuith Dr. D. i{urtak. Its purpose he.s been explained in earlier reDorts and by Kurtak et al. (t 9r,1 1. P.esurl ts Llp to June &his Jrear irrere presented in my last report. To investlgate L"he ti- er wing-t'-f t colouration is affected by v,ta't,er ternperatL.re, S. squanosum fro,n Boti Fal-Is uas reared, from egg to acl,.rlt in thc 1al..rcr.a..t o-r:i ar lovr teinpL-rature s of 20-22oC. Although c1e velop.irrt -,;as verJ,' slovu e nan;I ad.u.-Its i"rere obtained and preserved- f'ron e)ra.in.;ti:rn. This s'l,Lid-j,. is now virtually compl:te excep+. fep lf€ fj:rai aral;rs13 an;. presentation of resu.]-ts. E STUDIES O}[ Ir]E ECLOSIO;.' OF S. NA IiiOSTTIi COLPLH( SPECIES Inve s tisat1ons on S. squdosurx savamnah species have been descrihcd and a nrixed popul ation of irr earlier renorts. RecentLY, S- s anum and. -uirc been st'r.died. J-spot forn of S. soubrense/sgnctlpauli have -11 L'io pure popul eLr'.)o of S. sir'banum occlr.rs ,roa,J, Al:osortt,o but Dr. ailr,' i'lrs. J. frun,-'wa1c1 krnd-]-y agrre d to reoord ti^e r'el-,:v.,trt d.ata for .c:,1-,erl al :irorn lfa--,e, (Tabl,., 4). -if tcr c crre, ctron r..ho thr: f,upa.e !vere j.ic,1t'r, l\':r-t':1,1- t in i,lr,-. r'efrigera'[or. aei], nc, f ries emegge d. the fo1lo',:-i:--' cla-.r. EctoEioii cccLrrre:r thrc.,-Lfl.rlrt t.i,"e L exr, tvr: c-ays and at tl : cUrrit-,: r,ativeL$ h11'n r:.e vaillng terltp;-:ra:tu-rcs tite r,e wer,e tl:o pcak emcrgcltc'i p-rior-i.s br.fr-,rc O5.OO and betv;ecu 12.OO :inrr 15.0O horrrs. Ti:is -ai;noda1 --,--l-osion -rrr,t,:rn sug iests 1,rrrl iire ni:-,.-or siccn rJe.Ty emer'€,,encc- | ea,I: slown b,,, a poj-rulat i ;n of S. ia.:rrosum s. st,r . mixed_ 'riti-i soITI€. S. sirbanirr (see . arlier re,rorr,s) r ,,,os probably caused. by the l zrt tcr sp eci es . Str-rr1i-e s on t he J-snot llcrre of S oubr sanc tipa'-r1i h ave been carried or-lt on ti,;o pLrl:al col-lections froir the tsjgba Raplcls in the i/iono krver. Titc fir.st'#as roaoe ot 21/B/El and. the pupae were kept at temperatures ranglng from 25 2BoC. l, ith littl-e ciraqle durlng the day. The vast majority of f'Iie-s emcrged in the morningl many bcfore 06.00 and. r,rith a peak bet'vyeen o5.oo - o9.oo hcurs (taUf e 5). The se conc-L cofl-..ction of pupae (ll.l1 .91) 'rus kept at 25 3loc. l,ri.th peah tempera.tures 1n the afternoon arrd cooler mornings ( similar to thc-rse of the fi rst fi.ia] ) . Eclosion occurred throughorit the da;,,' ;'i'c h tr';o peairs betwecit 09.00 - 12.OO hourrs and 15.0O -'18.O0 hours b.,.t feur fl-ies emerged befor.e O5.OO hours (tante 6). Interpretatlon of the abo.re f incl inp s is f urther complicated. by the eclosicn paltterns shown by the lat:cratory reareo F,,, offspring of tfp tvro lots of f rclcl ;iraterial. Fl l-arvae clerived. lron the first col-lection 'ilere rearecl at rather constarit Iow tcnperatur es rarrging from 21 .5 Zt+oC. IiTevertheless the arLults obtained- energed -12 throu.gltout ti.c da.;r li.ke those of the s':co.ic, fibl-rl collecti-on lvhj-ch ',ra.$ k.iE,t zt ,r r1-'h iemp'.'r'atures. The F,,, offsrring of the second- coilcct tcn, ho,';evi.r, cme.f i,rcii aliirost en'r,iro1y in t,lre mor..ing. In eac.ir ct-se, i-.:--. (-:i".:ra, '"it,: F,1 reared. adulis exhibitcrl ttie ct:ergcnce pattern i:o'11 l; --r.,8[ l]V ,-,hi- p.L"tVioUS (parentat) generaticn. The reaSons for tircsc con.f', ictin,r" r-r-.9i:.1- ts are not understoc-,d. fire ecI,,sicn pattcr'ns of S. so,*-u-i cll Se s. str S. sanctipauli.9 and. S r l;'.1hcrr-:t i:o.,ia irt Lc '-.,e invc s ti gated. F. STi,D]IS Oi\' EGG :IOLOGY. i,,Lr. C.t-lar.lcs Kypr.ku (a: lt.Sc. studerrt undcr n19 supervision see earlre r rcrrorts) has ntleu']-y cc,nplc, ecl his thesis. Aspe cts of his v'rork on the egfs of S. d.a-rrros',-tn eonplcx species vui1l be r ef erred. to in -,:;r next r:epor-t. l'1.;ani,hiIe r his light-trappir:g of ovlpositing fer,rales is d.cscr'i'oeo. beIot,l. G. LIGI:T TRAP CC)-,LECTIOi[S OF OVIPOSTTT,}TG s s(:)i.TAl,/iosT'ix/i Sefvice (l'llg) uscci a. modified. ilonks foocl lip:ht Lrapr to collect oviposit:.ng S. seU&Lilosurl a.t Boti Frill-s. The 1arge n'r:-;rbcrs cau^ght sutErjsted ii:,at a nu.,iilcer of light Lraps stratugicall;' placed. near oviposition sj 1:;s ,ri5--h t unCer certaia circur;ist:'nces contribute signifi ear.tly to tlre ir con trol . Servi ee t ,s t.t'r ,-'" n^,zv'ai',,1 ti L. or-rglr : t thc ni-.ght a-nd the to tal catch l,ras c olIe ct,,-d ,.1 flawn :1.,: nr-.xt Jay. In order to asSeSS more pfeeiSCly ,,,,-''ren r-he fl- i .:s en ter th.; tr:epS, ca tr:hc-S wCI"e mad-e in August in wlirc: tjie traps ;ti:ra emntlef at in'iervals during the night. The vast lirajority of i.emal-:s coll-ec'ued., entered. the traps betvreen 18.45 .ric1 i 9.15 hcur's ;ust after ovipositing. Hard.ly any fI1es r/vcre tra'pcC aflcr, 21 .00 hours. Prel-il:ti-r:r',iz trail:s v.'itl.r chemical Ii3h*u traps (Service, 19BO) shoured, that the.r attracl!eo ,L.-- squaglostrm. Ilowever e the se traPs require a irore powerfuLl fatr to collect black-flies efficiently. 13 H. VISITIIG P"ESLARCII ,'Ortr(ERS. Dr. R.J. Cooter, frcr'r. the Centre for Ov,:rseas Pcst Research rn Lond.on, vlc-rr']^:ccl a.i; Akoscrlbo in *'ugrst and Sep"i; r: t'[:;r Coing tethcred. f1ig:ht st,:clies cir ioresL spi:cies in the S. uB,Yroslnn contpl ex . (tt" did. f::r,thcr rzalual;Ie r,vo'''r; a*. O'uiaga.cliu8ou on savannah flies). l'ir. K.R. SLr[rri.,t1s, i'rom the l.fniversit;i of ltiassachtrsetts, spent most of A'-'gust and,:arli Serd,enoer collabor'atii:g v'rlth me at Akc.rsoi'rbo::i,f, in Togo. i-lis rrisit ,ras fruitful- bc-cause \ile identified a VTest African laboratory mat -ng (s"" section ts I). r. PUBI,ICAT IONS. -'orl1 ln r,.l-:e S. clll Llos.,rli c ornpl- ex The fol-loi,ving papers have bec-r prepar'ed.: Sl-amons, K.R., Ra;'bouIC, J.ij., It{ered.ith, S.E.O. eurcl Gar;'ns R. Identification of a laboratory ma'cing J.'orrn in the Si:,^ul-1irn oEr..trosL,jl] Theobalcl c onplex in lilest Africa. Adiamah, J.H., Rairbotrltl, 'r.N., Kurtak, D. r Israel- " A. and liaegga B.T.A. Tire susceptibilit3' of Simlrl ium darrxrosum s.1 . ll.rvae f'roi^Lr tht-- Vol'L,a River ;n scuthern Ghana to temephos af ter ncarL;' u'ii:ir-r, !. L,.:' s trcatrient. J VTSITS TO RESiIARCi II;STIT- iTES /{{'J I\IEETII{GS. Dlring nty l-r-'ave in.ll',1rr I madc a nu:^.rber of unofflcial visits to var" ioLr-s resc'.'&r-c:-L cs'.a,rlislr'ta1t s r-r England.. Thcsc included. the Centre for Oversea.s Pest l'esi:areh, the Dj-ptera section of the Natural Histor;'- L,tusr:',.-*t, i,hc R.oss Insl,itLrte (alI in London) and the Wlnches Farm Flel-cl Cenre (at St. Al-t,ans) of the London School of Hygiene and Tropical- -'iciicine. I als:o attended the aru)ua1 meetlng 1Lt of th e Br i ti sh Sirrnf iu:n fjroLr.D (he1 o. or:. I rily 6ty.. a t i$e.r,eharm, Dorse t ) and con'rributerl to ilrc rligcussfctl. .fil,so dar';,it;a 't.i lcav,; in London, I spi.nt a fcr; :i::-n r-,Lth 1ir,. :'.P. Wir:t,:, fro.n tj-, -; Tr-i,-iagen fnstitute of Tropica.l -er'11s1n.r Sor t ag oilt +-1.: rcS,_.I_'s o_l ogr col_laborative worli at Atr.tscl'l|o :a.r1i,: r. iir ine year. r at ;;nc1:-:d. t he JlcPttia.i me: ti ng on re invo-; ion st;c iu s and rcscarch hcrl ,1 :rt L.rr,-,.r,- -Fi.-.r?. c),i' 21 s -, and ?_2rii lr, r.r ct. K. EDUCATIO}TAI ACTTVITIES orr llni i,-'cl I'atioiis Dar- r gave 'd l-ccturc on o.c.P. to the Ghana LTnited llatio:rs $f.,,,'-r'-ri ts Asso ,iation. In acrciition, a l-ecture and d.e",tonstratj-on on onchocJrc:i-aSis, .vrLh oarticular refi':rence to O.C.P. i''ras given to medical studen: s from Acera. Occasional advlce has also been of'fercd to i:ntoi;rolc;y st,uiicnte frorn the University of Gharr,a at Legon. L. \I/ORK PLA}INED FOR NEXT OUARTER Fev'r i.f ar..-' n.:v/ i.nrrcstl ,. ations i"ri-l--l- be star.ted btrrt the followi-ng stiidies u',.1-1 he cor-tiniLed a:nc wb.ere possible completed: (t ) Col-oni zal-:,ort of ',J-spot f,ormr?. ( Z ) Disp atcr of e,,.[.s -'or cot onization elsevyhere. 3) Improvc,ien t of bloocj-f e34i rg ::ates of 3-;;1.:6t f orrn. (l ) Comparison of or/i:-ro;:i tion inoucennent met,r:iods. (f ) Supervls ion of insecticide susce ltibil ii;, work. (6) Eclosj-on stui,lies. (Z) lTrltjng-up earllcr. yrork. ACIir'jOWLEDGEI,IE i\i lt s i alt most gra1tcf;I to al-I tjlose: rlentioned in thi-s reoort for their collaboratlon, adviee, help or s:.tpport. Tn partrcLilar I wlsh to thank l,{essrs. tr'. j,,.orrlzi-fa:mri D. tsoaL.:j-e, for efficient uork thrr,,ugl.out; DT.. S. '"rr-c4ith and llr. G. Fiasorgbor for cytotaxonomie i,lentiflc;af,,ieng,' Dr'. aid l'-r.s. J. Grune',.,a1-o for" collecting va1uable data; D::s. R. gnnrlrrj a:-,C P-.A. CjLekt _flor j dcnti_f ;riri6 adr_l1ts and sunrll-ing inrrterial; Dr. R.J. Ccoter f'ol. aclvice; Dr. D.C. Kurtak ancl l{eSSl-S. J.li. rL,-,iei."ah, C. Ilyor.i.::, j(.R. 1ji.',-,cils and Ii.P. V{irLZ for thelr fri,-;t'i.l-; cr:-L1;" ...;:. ,,.1-on a ,c -lr. .-r.:r. , -.,uku lor. typing thls report. -15 I am ind-ebtecl t o tlte V.R.l . arrC th.e l/.L.R. accomod.ation at Akcs,.,,bo ancl io ilre Ghana i,1r.1str;, sending Danicl Boaj.;.;,-e ,r.s a r,_search assis-tant. T\ iJ for iical th for on Ann. trop REFIREiVCES Brenner, R.J., Cupp E.l/., Bernard.o colonizaL:.orL anc--l life table stralns of Si-:r,lliur"ln de corLrTr L{.,r. (f ggO ). L:iboratory sta.ti stics -rrr. 4 Baragit., 2., 119 - 122. (Diptera: - 497. for gcogranhlc Si,aul1ida.e ). Tronenrte I Parasit. r 71 , 41; d: Scole s, C. '. g Bernar,-io, J''i .J., Erenner,, R.J. Po1 lack, R. A. (l qgt ). Clorrp.l-ete gcne ration rearing of Cupp, E W., Lok, -r.B l abora t oi ;, . J Simul-iul,r .'r.r'l:-rosr-;tr s.l-. (Oi;rl,era: Simuliidae) in the a 'i rc ,;c Lewis, D.J., Lyo;ts, G.p..L. e ilar.re J.l).11. Observatl ons Sinu.l iu ii ,f arnnos lnt ::'r',.',': the Reld Vof ta e 2O2 21(,. in GlLano. l{ed. Parasit C:Ft2 Dang, P.T. c* Petcrscn, B.v. (t 9Bo), pictorial heys to the ma.in sper.r ie s ancl s c ecl ur:; .;r oups within the Si.rr-iI1uni rfamnosun Theobald coirolcx occi-rr"ring in '[/est Af rlca (Olptera: Simr,:liioae ). ?ro-,:en,,ed.3?rB$.th rr31 , i17-1zO. - 16 Kur tak, D.C. , LaJ/blLl rl , J.r'r . a,r.d. Vafli,ne , cololus LT,. -lc p:o..'r-rlij ,:f ;-i::11 .' 6qUa:osu.i;r (Err,i tr'1e;:,). . !' J', , 1 '2'o. C . (t qt',t ) . r,'lri,rg tr:f t i ri :1 .- r i-c: u-a.ls tri S i, :.t i i uin D jr,ie ci .9C c, l) T, i\4ereCrth, S.I.L'., CiriI:e, R.A. & '-)arr,-rsrP.. ('traZ) . Variatj-on in S t^i'tl,.'l i ,--- . it, .',r- ,,-" :Lg- \rajim.; and D$abar :rrd. a -^.-rJ . D ArJ, c tip erul i \Ia i-i .re, a_t;l Dittba.i. :i.:i,1 l,he ciistr.r _,Ll r, j-.;t:- C)r,' rliffif ent f OfniS in 'ilr-ct ,{i r)_ca. Sr_:l-:uj-tted.. Ray-,ep1.1 , J. I. (",);:). St,.ir-'--ies ort lobc,re'1,or,-; rn.rtii:g in S. soubrense. fn: unprrlr-. l-:[r:C Q.,.iartcrly ]'e-r.)rt tc, O.C.P. , OuagadcuSoUr July S'.-,: f,. , !')79 y , -2 . Rpyboul-c1, J.i{., Prz'rco, T'.r S."',,adoEor R.e & iviordizlfa, F. 098 ?). A neyr,sirpl.-. l,_cl:r:riliUe.i_'cr r,laring F1 progenli from females of tha Si ,r-,1iun c1a' ::rosuin lhcol:al-d cdnpf ex. In press ' c'i Servioc, i.'r,rl. (f l;'g). Ligirr; Simurl i';m sqlrairosum t-:ap ecllections of ovi.-,oslt ing 1r" Ghana. o I"je d. Parasl t ., J ''s, )-''e'7 9C ' Servicee I[.''d,r. (198C). r. chcurical 11g1Lt .r a,p f'or mosqultoes and other 'bi t1:rg lnsr'cts. !\1ed Entcmol. ,1-ir 1?,3 - 185.T Slrr?nons, Ii.ir. and J.D. EO an " I981 a. Slrsta j-ire.-l coloni zatrcxt of tlre hla ck f.l-Jr S:-nu}1um clreccrru i7ir3.]-|4.r,rp (Oiptera; Sinr-rl . iriae ) . qgl " g. Zo*. ->91 1-7 . Siyirnons, Ii.R. ic .!d-nan, J.D. (f gaf n). -al:oTo-t-orJl col cnLzation of the hu-nan ol)-chorjerei asi s ve ctor Sinuii'-m dairtrosLEl cor:"tplex (oif tera: Simul- iir-16g ) L'.s intl an ellclo sed, gravity trc)lr.:\-1r rcSv ng s;rsfgr1. In Press. Sirunons, Ii.R. r !?aybo'.,.1C, J.l{., M.':t-ec}i lh, S.E.O. & Garms, R. (t 9gz). f :rentif ication of a l-aborej'ory rnatlng f ornt in the SinuL ir-u','r dan"rmosu.tt ?heobal'1 co'rtT:le-:( in '[fest African. Suhmi t tcc1. Ann. TAP,LE 1. DEVELOP iiirl OF EGGS LAI) BY S.SQjAIC$U'{ I'E'1rrLES I}IDLTCID TO OVIFOSIT Bi TrrE Illl.{ERSiOIT IEC!] IIQUE D.IRING I::E DAY ItT e, OTI Tf,Y OVIPOS]TIOl[ DTiIE DAYS }'FTER Ei,i.)oD-ilEAJ, 'in d ( DE1/EL,-P T1'I C. /O 25t 1o 1? 197 25Lt 21 318 )143 24 1 z4 133 2g 98 78 Z 32 C 23o 148 314 209 711 7 iB 529 1iB a') No. RETAI'ED !-'ATE OF ECC1S I,AID OF L/\I 1 Z 3 4 5 6 7 o o 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 31 .1C .e'1 ,1 .1 0.El 31 .1O.?n, 9.11 .)1 9.11 .81 9.1 1 .61 9.11.31 23 .11 .?,1 23.11 .'1,1 23.11 .81 23.11 .81 23.11 .81 29.11 .81 29 .11 .81 29.11 .81 7.12.81 .12 .81 .12 .81 .12.?.1 .12.81 .12 .81 .12.81 .f 2 .B,r .12.81 .1 2. rl) 20 .12. 20 .12 . 7 7 7 7 7 7 B B B B 1B U 15 q 0 0 B3 o o o o o o o 0 4 4 4 1 z Z 3 3 7 3 1 7 z) 7 3 7 3 3 3 2) z) 3 3 7) 1 2) 7 7 ,) 4lt 399 o o o o o o o 168 o o 6 535 .)J -aLt I 439 302 320 \2i 540 5llt 256 271+ )47 206 .)c ) -)t-) 205 255 112 239 312 37?, 'I t46, -_ -, '- F:91 .) Q- ,: )[ 136 639 02z 4ot1 47 l+l l+ 6S 79 5 9o 6g 4 0.4 10 IrO -/ 14 4t 23 1 12 o 80 47 B3 46 EO 2 4t B3 24 21 B1 81 81 81 IOTAL 11 65 1 0395 41158 43 ir lir l, nr -'r Jl Jt 1'l 42 371 160 l+3 TAtsLE 2. DEVELOPT E,T C}' EGGS LAID IY S -l ai, su.,' !,EI1,ALES Il\D,icED 'IO OVIPCSII 'lY T,jID I -lrERSrOl.- r,olIC-rrrlQiTE A'I lTlGIlT. FA?E OF EGGS l1o. OF rT,Y OVIPOSIT IOr' D.rTE DAYS T+FTER 'LCCD-IT,AI -T .^ RETAIi'[ID ]To. LAID lPnfu,oP rtrc 7' ( of,nttf ,OPTNG 1 2 3 4 5 6 7 o(J 9 '10 11 12 11 th 15 16 17 1B 1g 20 21 22 23 24 25 26 27 20.1 0.81 20 .10.81 20.10.8,'l 20 .10 .81 22.10 .?,1 22.1O .81 29 .1O.81 29.1O.81 29,10.81 29.1 O.Bl 29 .1O .?,1 29 .1O .81 29.t o .gt 9 .11 .81 23 .11 .81 23.11 .81 23.11 .81 23.11 .81 29.11 .81 29.11 .81 I O .12 .81 10.1 2.Bl 10.1 2.Bl '11 ,1 2 .81 23.12.81 23.12.81 23 .12 .81 i+ 4 )+ 4 3 3 3 7 3 7 3 -) 3 3 3 i 3 3 7 7 7.t trl 7 7 3 3 0 o 20 0 o t) t+7 ,47 2E2 LLO3 ,90 175 Ltrll 201 -t.cZ4( t 643 BC) B2+ AQ7I tt) 138 46t 446 207 339 576 287 433 162 250 426 500 235 1Bg 4Eo t+37 545 17 31 95 10c l+t 23._; lCO 6 3 162 3t L a-1 +Ll 4oe o 201 c) oo 10 I 13 413 t+7i 11 34 l+t 29B 13 4 5 5L+ 24 ZV oI 16 6 4 Bg 22 qo 91 U 52 14 3o 2 1 5 97 95 5 1B 9 oo 2 237 U o 0 2)r7 o 0 0 0 1 0 o 0 0 0 o 3 TOTAL 138\ 9i1o 3336 j)o IlEAid 5t 345 124 )o TAiLE 3. DE]IELOPIII]iT OF. SGCS IAID tsY S. SQUA.,,'OSIJ} FEIIII.IES I}TDUCED ?C OI/IPOSIT ?--1 l,;-X Sr r'6t'ig AITD ED .Lif TECtilrIQLfE. FA E OF EGGS No.0F FLY OVIPOS IT ION D+iTE DA]'S AFT]]R elooD-l EAt -,T ^ _!u. DTTAT}.I]]D LH?d ol-,,'Biopr,',o % (or r,eroEGGS ) DE\TEIQP ]NG 1 2 3 4 tr, 6 7 aL, 9 10 11 12 13 14 15 16 17 18 1g ._eo 21 22 23 24 25 26 20.10,81 20.10.31 22.10 .81 22.1 C . E1 22.10 .e1 29.1 O . :-,'1 29 .1O .81 29.1 0.81 29.1o .?,1 f0.1 0. 81 g .11 .81 9.11 .?'1 9.11 .81 29 .11 .81 29 .11 .81 29,11 .81 1O.12 .Bl 1 0.1 2,.31 10 .12.?'1 10 .12.81 1O .12.81 11 .12.81 11 .12.41 11 .12.?'1 11 .12.81 11.12.?r1 4 , 4 4 3 j 3 3 3 3 j 4 2) 3 7) Z 7 3 7 3 3 3 z) 3 1 7 7) 1 C) 501 o 21_c) 1 C 0 0 o Lru 319 2::c 114 DIC 744 SLir: 537 5\t '"9o 537 6lL+ 2?.3 258 295 150 7. A.) 118 204 43t trtG7, 590 (1.sa 'J) | 294 I !-t3 529 360 181+ )13 b 618 31o 6sg +90 5oo _)oo 514 6oz 239 245 157 157 21 15 72 155 421 545 515 66 47 524 86 rO)t) 16 E 95 97 100 91 78 ht-) 95 89 Bh 95 53 OQ 7 13 35 35 75 93 e4 22 33 99 o ri o U 0 r! 0 0 16 52\ 73 3B 12 4 i1 4t 130 0 TOTAL 1826 1O7rO D,O51 75 }iEA}T 70 )$3 310 75 I TABLE 4. Ti{E TI 'i'Tj'j G o 5I' ECLOSIOIJ OF S. SIMBA}TLI}' (Pupae coltectcC at Yer.bo anrl leept t.n thc refriiiera.Lcr over ni6;l-t). J0.9. Bl E. Jr.r 1J.OO I '.Oo ' 1'E .00 DUD3.C t:, . )r) 7a ^ 3L.o arf iLvca 0 o o o o 0 o C 0 C 0 o 1.10.81 6.o7 9. oo 12.OO 15.00 18.00 25.5 It.: . ) 32.O 32.5 30.o -r -1-'. ' 25.5 2r,.5 3?.C 30.o l0 .0 2c.a 32.A 7)tr 33.5 9 0 2 5 3 12 7 1 14 3 14 37 7 3o 2 2.1 0. B.,l 6.o5 9. o0 12 .O5 15.OO 18.O5 Dtr. tr ZU.U 31 .5 32.O J0.o 2r.5 30.o 20 26)l:. tr 10 13 5 1 I 10 13 o -2) 3 10 28 .0 .o .9 tr zl) 31 33 5 431 .5 30.o 32.O SU'I'IARY 6. oo 9.00 12 .OO 15.00 18.00 S. SIii -]fl,l rJLi FEi'AL:S :.AI,E S ]OTAI 27 13 5 3t 9 15 16 12 10 l+ 42 29 17 4t 13 Txi,pr.jliA-,..,j l?E oC S. SIR,BAjjul DATE .L,I __E AC-r,'.A1; i. flr . jtAX lE, ;;LES I,;AL5S TOTAI { ) FORI,; OFS SOUB,!EllsTA LE '. SA]CT /.LT,I COLLTCIi) FRO ?.E tsEGtsA RAPIDS O]{ 23/B/ii ( rt'r pvu'irrc) (i.lol.t iri cold bc',x thrt.ughctrt n,-,'t ,iaJ). j)n TE:lP riiAi :lE "u 'o. 0F !'LIES DATE TI ''E lt4"{ T . . AC T;.]AL I' ',{..E I I]I AL E TOTd, 0600 2B.C 2a.Ll 2,-:.0 1g 2.,' lJ7 o9co 25/B/8t 12oo 12 l+O ?? .c Za.i 25., 5 4 1c 1 500 27 .e: 2i.O 27.o 1 I ,2 1 300 27 .O 25.C 26.C O 0 o 0,500 2a) .5 2).C 26 .5 t 6 2Lt 4O 26/a/n1 o9o0 2-1 .O 2.-..5 27 .O 4(, 2-,' 73 1 200 2).O 27 .O 2B .O 16 11 27 1 500 2?,.5 25.5 27.O 34 7 'i 8oo 2?,.O 26.0 26.0 2 Z 4 o5oo 27.O 2)+.5 /+.5 6 1 7 o9oo '25.5 2)1.5 25.5 52 33 85 zt /e/st 1 200 27 .' 26.5 27 .5 19 5 2l+ 1 500 27 .5 27 .O 27.O 4 1 5 1 800 27 .5 25.5 2€, .O 2 o 2