Five insecticides and three mixtures were tested on the cotton flea beetle (CFB), Podagricapuncticotis (Weise), the spiny bollworm (SBW), Earias insulana (Boisd.), and the cotton aphids (CA), Aphis gossypii (Glov.). The relative potency (in terms of LD50 and or LC50) for CFB followed this order: endosulfan + dimethoate > endosulfan + chlorpyrifos > dimethoate > fenvalerate > endosulfan > endosulfan + amitraz > amitraz. The LCS0 values ranged from 12. 0–1150 ppm. For SBW, the following order was obtained: fenvalerate > endosulfan + dimethoate, endosulfan + chlorpyrifos > endosulfan > dimethoate > chlorpyrifos > endosulfan + amitraz > amitraz. LC50 ranged between 0.35 and 3388 ppm. With regard to CA endosulfan + chlorpyrifos > endosulfan + dimethoate > endosulfan + amitraz > chlorpyrifos > endosulfan > fenvalerate > dimethoate > amitraz.
In general, C A was relatively tolerant to most tested insecticides when compared with the other two pests. The SBW was the most susceptible.
