Proposed entomology research programme on fly movement for 1976

@ ONCHOCERCIASTS CONTROL PROGRAMME IN THE VOLTA RIVER BASIN AREA SCIENTIFIC AND TECHNICAL ADVISORY COMMITTEE Ceneva, 2-4 March I9?6 Agenda item 9 on fly movement for 1976 by P.T. Haskell ocP/srAc3.4 ORIGINAL: ENGLISH RESTRICTED Centre for Overseas Pest Research Ministry of Overseas Development United Kingdom Proposed Entomology Research Programme IONCIIOCEI1CIASIS CONTROL PROGRAMME Scientiflc & Advieorrr Committeo. Ganeva Harch 2-4. 19?6 Proposed catoaoloFr Reaearch prorra.one on flv novement, for 19?5. (Agenda Item ? ) 1. It ia not poaalble to makc a dctailed criticlan of the 19?6 OCp reeearch pro8ramme on adult fly novcnent. sLnce yc havc only an outline of the reeearch propoaala. Houcverl fror thcac it appcara that the aln of the reaearch ln 1975 ls to find thc aource of the nies utrich invade the Bandana. The following aaaunptloaa hava bcan nadcr (i) There ie a etnglo aounco (1i) For each invasion the source is the eane (iir) since the Bandama wa6 invaclcd i,n 19?5, it $irI be invaded in aubecquent yeara (ivl Iiubsequent invasione of the Bandama will occur at the eaoe time of year as the 1975 invaaion 2. The search for a posaible source of the invading flies appears to be g,oing to be concentrated in southern Ivory Coast and sorrth-western Ghana. There is no evidence that the 1975 lnvasion occurred from these areas or that these areas would provlde the only source of flles. It is also urilikely that there is a sin8le aourco of the fliea accunulating in zoner of winci convergence. This, togethcr rtth the fact that the direction and dlstance a fly will be dieplaced. rlll dcpend not only on the duration of flight but aleo on time and placa of takc-offt neana that individual invasions yill not be id,entical although the end reault uay bc thc asrrc. 1. One of the oain drarbacke to thc aeeuoptiona bahind the rosearch propoeals is that by conccntrating on oae apeciflc area, other invasions nay be miseed. The recent and subeequent invaelons of the Bandana are aesuned. to bc localieedr but there ia no evidence for this because thc catching systen ueed in the OCP a -2- Area ia not geared to estirnate the extent of eny invasion. Hence, by concentrating all res,'arch rosourcea in er singie arear there is a rlanger that other. equally import;rnt movements r+ill not be monitored oufficiently. In addition' there ia also thc poseibility that the Bandama will not be invaded in 19?6 (19?5 uaa the first year a reinvaslon was noticed; it nay have been an unusuar year e.g. the firet wet year after a period of dry years). 4. Ihe timing of the reoearch programa ie critical. Uit:rout daily monitoring of fry nunbere throughout the year, it ie imp.;eaibre to cven guess whether fluctuationa i.n fly nu.abera are due'to imaigration or to local breeding, although adnittedly marked differences in size and a5e structure do suggeot immi6ration. It is inportrurt that the fly popr.rlation ehould be monitored thro rghout the year or {rny invasion may p:r€;s unnoticed, since it is unlikely it would be noticed except at the very beginning of the invasion. There is certalnl-y no reason to asaume that the timi.ng of an;' invacions wi'l lle the s;,me aa the 19?5 one. 5. A 5re.'t tleal of effort is also going to be spent on detailed cytotaxontrmic, and morphometric work in an atte int to find a source. .'lince with {1. damnosum one i8 dealing with a highly rirobile and a.laptable insect it seems unl-ike1y that one specific fom of the fly will be foun I to originate from one particplar area. fn Senera1 terrsr virtually evety cytotype can be found somewhere in the OCP Area throu6hout the year. Froo the cytotaxonornic rvork which has been done it appeara that different fonBa of the fly can be found et the saae slte at different times of the ycar and therefore. without further researrch of this narture throughout the entlre OCP Area. it scems unlikely that if a certain cytotaxonomic type appcars on the Banrlema it can be traced to a speciflc arca. 6. tJe have no detaile ebout exactly where the reeearch is going to be done, what the sampling network and frequency of oarnJrling will be, or for how long I I-r- tho rcecareh programmc uill bc carrtcd out. Por bio6cographical rrork, daily catchin6 la rttal but cvcn ulth thia. ytthout baatc ros.rarch on fli5ht bchavlour' crp.ciarry tioe of takc off. dtrcctlon and hel8ht of frlght we cannot usc back tracking techntquca to locatr poaaible aourco ar6as. 7. It muet bo oophaaised that theso conmcnts arc based only orr a trrief outllnc of thc reacar"ch propoaalo but our vicn hcre bascd on lon6 experlence of the study of air bornc in.-iccts ia that thia progr.rmmo nould not pr.oduce data on fly movement of the type neceaoary and rroulC be largety rrariteful o.C rcsources and expertise for little likely result. P T Haakell Centrc for Overaeas Pest tiescar^ch 12th February 1976 I t. I