With the present invention it has now been found that certain 4-(trifluoromethyl)pyridine compounds and active compound compositions comprising such compounds are suitable for controlling nuisance, disease carrying or blood feeding dipteran and cimicidae insect pests by knockdown. In one embodiment, dipteran pests are selected from flies and mosquitoes, including insecticide-resistant flies and mosquitoes, as well as fly and mosquito vectors of pathogenic disease. Target cimicidae insect pests are selected from bed bugs. Other aspects of the present invention will also be apparent in the detailed description which follows.