5-(Bromomethyl)-2,4-dichlorothiazole is an intermediate for the synthesis of 4-Chloro-thiamethoxam (C369940), which is an over chlorinated impurity of thiamethoxam (T344180), a neonicotinoid insecticide. Reports show that when exposed to neonicotinoid pesticides honeybees have problems returning home after foraging and bumblebee colonies grow poorly and produce fewer queens.