SUMMARY Screening trials showed that many insecticides killed chrysanthemum leaf miner (Phytomyza atricornis Meigen) adults and larvae inside chrysanthemum leaves but not eggs or pupae. Residues of demeton‐S‐methyl were not completely effective against adults and DDT did not kill larvae. In commercial glasshouses, complete larval kill was consistently obtained with high volume sprays of 0.02 per cent diazinon, 0.05 per cent dichlorvos and 0.023 per cent thionazin; 0.04 per cent azinphos‐methyl, 0.05 per cent nicotine and 0.01 per cent parathion gave nearly complete kill; 0.0125 per cent gamma‐BHC, 0.02 per cent demeton‐S‐methyl, 0.11 per cent malathion, 0.025 per cent morphothion and 0.19 per cent oxydemeton‐methyl gave variable and sometimes poor results.