ARTHROPO DMANAGEMENT Methomy lResistanc ei nStrain san dCrosse so fTobacc oBudworm: Degre eo fDominanc ean dPatroclinou sEffects

Afield-collecte d(field )an d asusceptible referenc estrai no ftobacc obudwor m[Heliothis virescen s(F.) ]wer ecrosse dt odetermin emod eof inheritanc efo rthei rrespons eto methomyl (Lannate) .Th efiel dstrai nwa sno tselecte dbecause w ewante dt odetermin eth emod eo finheritanc eo fa non-selecte dstrain .Ou rresult swer edifferen tfrom previou sresult so nth einheritanc eo frespons et othis insecticid ewit hothe rstrain so fthi sinsect .Methomyl wa sapplie dtopicall yt oprogen yo fth efiel dand susceptibl estrain san dcrosse so fthem .LD50 values (a sµ gmethomyl/larva )wer edetermine dafte r4 8h. Probi tanalysi swa suse dt ocalculat e95 %confidence interval san dslope so fregression .Th eLD50 valu eof th efiel dstrai nwa ssignificantl ygreate r(17-fold) tha ntha to fth esusceptibl estrain .Th eLD50 value sof bot hreciproca lcrosse so fF1 an dF2 wer enot significantl ydifferen tfro mth eLD50 o fth efield strain ,indicatin gtha trespons et omethomy lb ythis fiel dstrai nwa sdominant .Th eLD50 o fsusceptibl ex fiel d(femal eliste dfirst )i nth eF1 reciproca lcros swas significantl ygreate rtha nth eLD50 o ffiel dx susceptible ,indicatin ga possibl ese xlinkage .Results indicat e apossibl epatroclinou seffect.