All the tested B. thuringiensis isolates were found effective against S. obliqua larvae collected from different locations. Among all the tested isolates least LC50 were noticed in case of Aligarh population in particularly unfortunate. Low level of resistance was reported in Plodia interpunctella (Hubner), the Indian meal moth, in storage bins of B. thuringiensis treated grain. Entomologists have documented three cases of field-evolved resistance to Bt crops (Frisvold and Reeves, 2010). Keeping comparison to Delhi population. However, trend was changed in case of LC90 where Btk Path-1 and Bt galleriae registered higher LC90 for Aligarh population. Trend was maintained in case of LC99 where Btk Path-1, Bt galleriae and Bt entomocidus registered more LC99 for Aligarh population. Finally Delhi population registered more LC99 except Btk Path-1, Bt galleriae, Bt entomocidus, Bt aizawai and Btk HD-73 against S. obliqua larvae.
Susceptibility, LC values, B. thuringiensis
