author(s)
Chandan Maity, Palash Mondal and Laltu Mondal

abstract
Tomato (Lycopersicon esculentum Mill.) is one of the most popular and commercially important vegetable crops in India. Among many factors responsible for low yields of tomato, insect pests are major ones that have been reported to attack tomato at all stages of crop growth. The damage caused by fruit borer, Helicoverpa armigera (Hubner) surpass the loss caused by all other insect pests together and it has been reported that the loss due to this pest ranges from 20 to 50 per cent. To address the issue an experiment were taken up where three entomopathogens were evaluated against Helicoverpa armigera to generate information regarding LC 50 and LT 50 along with five newer molecules. Observation data indicates the supreme toxicity of Emamectin benzoate among all the treatments as its shows lowest LC50 values on 12 and 24 hours are0.37 x 10-4 and 0.11 x 10-4 ml/l, respectively. Whereas, among microbials B. thuringiensis displayed lowest LC 50 values i.e, 5.0 x 108, 0.58 x 108 and 0.12 x 108 IU/gm, respectively, in 96, 120 and 144 hours. In terms of Median lethal time (LT50) was estimated for Emmamectin Benzoate (8.81 hour) was observed lowest followed by Cyantraniliprole (15.09 hour), Chlorantraniliprole (35.54 hour), Flubendiamide (44.41 hour), Spinosad (44.62 hour), B. thuringiensis (83.72 hour), HaNPV (114.58 hour) and B. bassiana (154.63 hour). This result is good evident of potency of newer molecules against H. armigera and it is well established that entomopathogens also has moderate level of efficacy which have no adverse effect on environment.