Field experiments were conducted in two agroclimatic regions of Rajasthan (the semi‐humid Udaipur in 1979 and 1981, and the semi‐arid Jobner‐Jaipur in 1980 and 1981) to evaluate the insecticides, chlorpyrifos (0.05%), ethion (0.05%), phosalone (0.035%), dicofol (0.1%), carbaryl (0.2%), toxaphene (0.1%), malathion (0.05%), endosulfan (0.07%) and dimethoate (0.03%) for the control of the pumpkin beetle and the fruitfly damaging musk melon var.Durgapura madhu.Four spray applications of 0.2% carbaryl at 3, 5, 9 and 11 weeks after sowing proved most effective against both the pumpkin beetle and the fruitfly, and resulted in increases in yield of between 79 and 89 q/ha, and net profits of between Rs 5526 and 6246/ha, over the check. Sprays of dimethoate and phosalone were found to be effective against both pests and also gave higher benefit/cost ratios because of low costs.