author(s)
Toma Chakraborty, Naznin Nahar, MST Rokeya Khatun and Gopal Das

abstract
In the present study, experiments were conducted in the laboratory of Department of Entomology, Bangladesh Agricultural University, Mymensingh-2202 to evaluate the potentiality of some promising insect growth regulators (IGRs) viz. Buprofezin (Award 40 SC), Lufenuron (Heron 5 EC) and Pyriproxyfen (Pyrifen 10.8 EC) on the mortality of bean aphid, Aphis craccivora (Koch). Each of the IGRs was tested in three different concentrations (0.5, 1.0 and 1.5 ml/L) following three application methods namely direct (topical), indirect (leaf-dip) and combined (topical+ leaf-dip). Data on mortality were collected at 1, 3 and 7 days after treatment (DAT) application. All selected IGRs were found very effective against bean aphid in the laboratory condition. Mortality of bean aphid was clearly dose, time and method dependent. No mortality was found at 1 DAT while mortality was reached to significant level at 3 DAT from all application methods but the highest mortality was found at 7 DAT. Highest mortality was recorded through combined application method @ 1.5 ml/L (85 to 93%) which was followed by 1.0 ml/L (~80%) and 0.50 ml/L (60-70%) respectively. It was also observed that combined application method along with highest concentration was found very effective than topical and leaf-dip method regarding mortality.