01975naa a2200253 a 450000100080000000500110000800800410001910000230006024501600008326000090024349000140025252012440026665000150151065000130152565000110153865000260154965000100157565000090158565000110159465300120160565300100161770000190162777300750164619527762022-04-29       2012    bl uuuu     u00u1 u    #d1 aSOSA-GÓMEZ, D. R.  aFitness cost of resistance to bacillus thuringiensisin velvetbean caterpillar anticarsia gemmatalishübner (lepidoptera, noctuidae).h[electronic resource]  c2012  a0085-5626  aSelection pressure to obtain resistant genotypes can result in fitness cost. In this study, we report the effects of the selection pressure of a commercial formulation of Bacillus thuringiensis on biological aspects of a Dipel-resistant strain of velvetbean caterpillar, Anticarsia gemmatalis Hübner. Comparisons of Dipel-resistant and susceptible individuals revealed significant differences in pupal weight and larval development time. Both strains (Dipel-resistant and susceptible) were susceptible to Cry1Ac toxin expressed in foliar cotton tissues. Resistant and susceptible strains showed low survival rates of 22.5% and 51.2%, respectively, when fed with Greene diet containing Bt-cotton. Larvae bioassayed after three laboratory generations presented lower survival and less instar numbers than individuals maintained in the laboratory for more than 144 generations. Pupal weight was 9.4% lower and larval development time was 1.9 days longer in the resistant population than in the susceptible strain. Other parameters, such as duration of pupal stage, adult longevity, number of eggs per female, oviposition period, and egg fertility, remained unaffected. Keywords: Anticarsia gemmatalis; toxin; Cry1Ac; Dipel-resistant; strain.  aAnticarsia  aSoybeans  aToxins  aAnticarsia Gemmatalis  aRaça  aSoja  aToxina  aCry1 Ac  aDipel1 aMIRANDA, J. E.  tRevista Brasileira de Entomologiagv. 56, n. 3, p. 359-362, Set. 2012.