Variation in susceptibility of Helicoverpa armigera (Hübner) and Helicoverpa punctigera (Wallengren) (Lepidoptera: Noctuidae) in Australia to two Bacillus thuringiensis toxins

Susceptibility of Spodoptera exigua to 9 toxins from Bacillus thuringiensis

“…Larval growth inhibition has been used to determine susceptibility to individual B. thuringiensis toxins in a number of insect species, such as Helicoverpa armigera (MacIntosh et al, 1990;Sims et al, 1996;Avilla et al, 2005;Bird and Akhurst, 2006), Helicoverpa zea (MacIntosh et al, 1990;Siegfried et al, 2000), Ostrinia nubilalis (Marçon et al, 1999) and Diabrotica virgifera virgifera (Siegfried et al, 2005). To our knowledge, no study on individual B. thuringiensis toxins on growth inhibition has ever been published on S. exigua.…”

Environmental Impact of Genetically Modified Crops

“…In addition, field-evolved resistance has been reported to Bt corn producing Cry1A in Busseola fusca in South Africa (Van Rensburg, 2007) and to Bt corn producing Cry1F in Spodoptera frugiperda in Puerto Rico (Matten et al, 2008). Published data also provide evidence that resistance to Bt crops has not been detected in monitored field populations of H. armigera, H. virescens, O. nubilalis, P. gossypiella and Sesamia nonagrioides in Australia, China, Spain and the USA (Tabashnik et al, 2003(Tabashnik et al, , 2005a(Tabashnik et al, , 2006(Tabashnik et al, , 2008Farinós et al, 2004;Stodola et al, 2006;Bird and Akhurst, 2007b;Downes et al, 2007;Gahan et al, 2007;Siegfried et al, 2007;Wu, 2007).…”

New Tools and Traits for Cotton Improvement

“…Overall potency of a Bt cotton will depend upon the Bt proteins expressed and their levels within the plant (dose). In general terms, Cry 1Ac and Cry 1Ab are very effective against most genera except Spodoptera; Cry 2Ab is effective against all genera; Cry1F has strong activity that includes Spodoptera, H. virescens, and Pectinophora; and Vip3A also has excellent activity against Spodoptera with moderate activity against several other genera (MacIntosh et al 1990;Estruch et al 1996;Sims 1997;Sivasupramaniam et al 2000;Green et al 2003;Adamczyk and Gore 2004;Bird and Akhurst 2007). These complementary activities are reflected in Bt-expressing cotton products either in the marketplace or approaching commercialization.…”