The efficacy of ZeroFly? Screen, insecticide incorporated screen, against nuisance and biting flies on cattle kept under zero grazing system in the Northern Zone of Tanzania

摘要

AfieldtrialwasconductedfromDecember2012toJune2013toassesstheeffectivenessofZeroFly?Screen,aninsecticideincorporatedscreen,againstfliesoncattlekeptunderzerograzingsysteminnorthernTanzania.Sixanimalsweredistributedinasmanystandardzero-grazingenclosures.TwoenclosurespersitewereconstructedatthreesitesA,BandC.AnimalshousedintheenclosuresatsiteAhadtheirenclosures(A1,A2)fittedwithZeroFly?ScreenwhilethoseatsiteB(B1,B2)hadinsecticidefreescreenofthesamematerialasZeroFly?Screen.TheremainingpairwaskeptinenclosuresatsiteC(C1,C2)withoutanynettinginstalledbutweresprayedwithEctopor?SA20aspermanufacturer#8217;srecommendationtoserveasthepositivecontrol.BaselinedataonflypopulationswerecollectedpriortoinstallationofZerofly?Screens.Flieswerethencaughtaftereveryfortnighttomonitortheirpopulations.Biconicaltrapsplaced3-5metersawayforaperiodof48hours,oneforeachenclosurewereusedtocatchflies.TheresultsindicatedthatZerofly?Screenwhenusedaloneiseffectiveincontrollingbothbitingandnuisanceflies.ThepopulationdensityoftsetsefliesatsiteAdroppedfromthemeancatchof3.75flies/trap/day(FTD)beforeinterventiontomonthlymeancatchof1.75,0.625,0.5,0.375,0.25,0,0.25FTDinDecember,January,February,March,April,MayandJunerespectively.Ontheotherhand,thepopulationdensityofhousefliesdroppedfromthemeancatchof103FTDbeforeinterventiontomonthlymeancatchof34,11.25,2.5,2.75,3.25,2.5and3FTDinDecember,January,February,March,April,MayandJunerespectively.Tsetseflypopulationdensitywassignificantly(p=0.006)loweratsiteAwhencomparedwithsiteB.Nevertheless,therewasnosignificantdifference(p=0.872)betweenthepopulationdensityoftsetseflyatsiteAandsiteC.Thedropinpopulationdensityofhouseflieswassignificantly(p=0.000)lowerwithrespecttositeB.However,therewaslittletochoose(p=0.922)betweensiteAandsiteC.LaboratoryfindingsshowedthatMuscadomesticawerehighlysusceptiblethanpregnantfedGlossinapallidipes.AlthoughtherewasanincreaseintimeforknockdowneffectforthesamplestakenfrommidDecember2012tomidJune2013,100%mortalitieswereobservedonallexposedflies.Inthisstudy,Zerofly?Screenhasshowntobeeffectiveagainsttsetsefliesandhouseflies,hencecanbeusedforcontrolofnuisanceandbitingfliesinTanzania.