Toxic Effect of Some Insecticides on Predatory Lady Bird Beetles (Coleoptera: Coccinellidae) in Country Bean (Lablab purpureus L.) Field

The study was carried out in the entomology research field at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh during 2009 to evaluate the effect of some insecticides on the abundance and mortality of predacious lady bird beetles in country bean; Lablab purpureus L. ecosystem. Among the insecticides, Neemoil (fresh) @ 2.5 ml / L water, Curtap 50 SP @ 2.0 g / L water and Emamectin benzoate 5 SG @ 1.0 g / L water ensure highest number of lady bird beetle in the treated plot resulting 22.45, 17.97 and 15.63 adult lady bird beetles per plot area respectively. On the contrary, lowest number of lady bird beetle was found in Fenvalerate 20 EC @ 1 ml / L water, Cypermethrin 10 EC @ 1.0 ml / L water and Esfenvalerate 5 EC @ 1.0 ml / L water treated plots resulting 10.67, 11.43 and 12.72 adult lady bird beetle per plot area respectively. Neemoil (fresh) @ 2.5 ml / L water, Neemoil (stored) @ 2.5 ml / L water and Emamectin benzoate 5 SG @ 1.0 g / L water found least toxic to lady bird beetles confirming 9.37, 17.45 and 19.04 % mortality respectively. Esfenvalerate 5 EC @ 1.0 ml / L water, Cypermethrin 10 EC @ 1.0 ml / L water and Deltramethrin 2.5 EC @ 1.0 ml / L water found highly toxic to lady bird beetle resulting 33.78, 31.76 and 28.42 % mortality respectively.