Evaluation of ethiofencarb (Croneton) 50% EC (Bayer) as larvicide against simulium damnosum sl

1'/0RLD ORGANI ETT'ECTS AGA]NST S. DA]VINOSUM S.L. IN SECTICIlE Ethiofencarb or Croneton j}ft EC supplied. by Bayer. ORGANTSATI ON }{O}ilD IALE DE LA SANTE formulation, Batch No FL Z59O/L57 (t titre) was t EVALUATTON 0F ETHrOFmrcARB (cnouoroN) 5e/, EC (BAYER) AS LARVICINE AGANST SN,{ULTUM DAMNOSIryI S.L. TEST METHODS The closed.-circuit trough system was used, in testing this formulation. TEST STTES Evaluation of the larvicide was carried out by OCP Staff in Southern Togo. Larvae of.9imuliu$_d?mnosum s.1. which were used. for the tests are lcaown to be nozmally suscep-tible to all insecti.cides. RESUITS A- TrouEh Te sts Resul-ts from two series of tests Jrr troughs (each with one replicate) are summarised.in Table 1. Data from tests with temephos the standard. OCP l-arvicide, axe also presented.for comparison. The results obtained using the trougJhs which are the stand.ard. testing equipment, show that Ethiofencarb has a rather,poor activity on larvae of !. d.amnoqr:m s.I. Dr:ringexposure at a dosage of or5 rr.g,/t/tol the larvae showed littre i?=iffiilnd. onIy, smalI proportion got d.etached.. !/ith increasing dosage - Lr5 ngft to JrO ng/L - Iarvae became more agitated. and ? proportionally greater number of larvae detached in the course of exposr:re. Feed.i-nginhibition was observed in some of the larvae at higher concentratj-ons. Larvae that gotd'etached jnto the nets appeared. to be only morrlund or even sti1l aLive several hor;:safter exposure. Temephos 2A/o EC, produces 10@6 mortality at between OrIJ mg/f ana orit^r/t B- River Tria1s No river trial-s were conducted, with this formul-ation j:r view of its Iow efficacy onthe S. damnosr:m s.1. Iarvae in troughs. 1984 -2- C- Comments on formulation Ethiofencarb (Croneton) 5O/o EC is a light ye11ow oiI which mixes easily in waterto forrn a white, homogenous ermrlsion. The emulsion remails stable for several hours when kept standing. Foaming occurs when the mixture is prepared. and. the foam remains on the surface for hours. DISCUSSTON AND CONCLUS]ON The activity of Ethiofencarb was found. to be rather 1or+ against Simulium d.amnosun s.1, larvae. Low d.osages caused. very little detachment of larvae. ly incr@T@; t,o JrO ^g/1, onLy )5rfflo d.etachment of mature larvae was obtained. This is between 10 and2l times the d,osage that gives 100/o mortality with temephos. River trials were not attempted because of the 1ow efficacy of the formulation on the larvae. However, Ethiofencarb being a carbamate and an emulsifiable concentrate which is in a d.ifferent class of insecticides from temephos it is recommended, that thefi:rn improves upon this formulation so as to meet the requirements of OCP. a E tdH E! H il ll lt lt ilII il lt ll ti ll ll lt ilI il lr li il II il ilI il lt il il H lt il il il il ll ll E o a CF o U s) cl- o E o5 tsd o E B I COs I N) o\ P{ \o 0os N)\rl c)o .\l \N F3i Hd F.p P. J o5p, tr ct P. P' cl- E o x P. o P. cF cl- o :Jp ct-f o H s) H p o ob lor p, g) 5 ota Itr IB a a P il il il il lt ilI lt ll il il il il il ilI il il il il il il il lt il ll ilI ll ll il II llI il ilI ll il il il il lt ilI il il il lt lt il il il il il ll lt il llII il lt lrI rl I E o :J oFd o a F o H $) 0q o + o H \o cl' o a cl a ll ll il il lt il il il ilI il II lt ll rlI il il il il il lt ilII il ltI ll il ilI il il il ll il ilII lt ilII ltI il il il il il II lt il ll II lt lt il llI il il il il ll a E3F !d O r.d E aq E L-l U)Ea HE E € HO r_d Fr1 C) :d td !ne o\ t5C) ll il It- lt il il il il lt ll lt lt II II II il il il I Ii I lr ll lt lt lt il il lr il II lt Hoo Ff H\N @ tra o E o\ -B .t\) o;< s) o =JpooFJP ct TD \N lJeP.O ct<ts a_ P il ll il ltI ll il il il lt II lr lt ll lt II 1I I ii il ltI il II il il 1I il ti it il ll lt ll il il il II il II il II il il lr il il il il il lt il lt il III lt il II II il il il il o O CO O o\o\ O H \J., I o N)\] ilz \O cl- € I @5 IH N) tu s. co co5 N) __l c)o --l s H5 E H\nln trq_ g O o\ --l TJ c) \, \o N) 5 \o\, ilz oO\ cF __l -H =too\ g) o 5pooFJ P,+grH ts. \, cl-<E a_ P H C) Hr-l O od a o H 4 op il il lt lt lt ll l, II ll ll lr il lt t' t, il il It il il ilI li il il il il II lr il lt il il il il il ilI I il ilI il il il il il lrI il ilI il II il il ll lt lt il lt lr ll il il il lt ll II ilI llI il il il il II il ilI il ll ilI II il il lt il lt il llI II il lr ll lt il lt