author(s)
Mohammad Mustkeem, Parvez Qamar Rizvi, Mohammad Haniph Shah and Hadi Husain Khan

abstract
The present study entitled “Studies on the Nanochemicals and conventional chemicals against Helicoverpa armigera (Hubner) on Chickpea (Cicer arietinum L.)” was conducted to determine the efficacy and dose-response relationship of Nanochemicals in comparison to few conventional and widely used insecticides against IInd and Vth instar larvae of Helicoverpa armigera (Hub.). The efficacy of copper, silver, manganese and neem seed kernel extract (NSKE) in Nanoform (30-50nm) and conventional chemicals viz., imidacloprid and Neem Hakeem was assessed on IInd and Vth instar larvae of H. armigera (Hub.). The respective Nanochemicals were evaluated @ 1:10, 1:100, 1:200, 1:500, 1:1000 and 1:2000 dilutions by topical spray method. The lower dilutions were found more efficacious and produced the maximum mortality of both instar larvae. Among four Nanochemicals and two conventional chemicals, Nano-silver was found comparable to imidacloprid. The chemicals were found more toxic to IInd instar larvae, Nano-silver and imidacloprid caused 83.33% and 86.66% mortality at 1:10 dilution, which was maximum in all chemicals. The Vth instar larvae showed less susceptibility towards these chemicals and caused 70% and 76% mortality with respective chemicals. Nano NSKE and Neem Hakeem produced the minimum mortality i.e., 66% and 63% on IInd instar larvae and 53% and 56% mortality of Vth instar larvae at same dilution on 4th day of exposure. The other Nanochemicals like Nano-manganese and Nano-copper exhibited the intermediate effect on larval killing. The LC50 values computed for manganese, silver, copper and NSKE, neemhakeem and imidacloprid on IInd instars were 0.0032, 0.013, 0.012 0.047, 1.057, 0.054, respectively. Whereas the LC50 values of respective chemicals on Vth instar larvae were 0.098, 0.061, 0.078, 0.082, 1.573 and 0.058. During the periods of heavy infestation, Nanosilver and Nano NSKE (30-50 nm) can be applied as protective measures. Nanoparticles were found effective in this study, therefore the work on enhancing the usefulness and commercialization of Nanoparticles could be a better alternative over conventional insecticides.