Several studies on the dengue vector Aedes aegypti in northern Queensland have revealed a considerable percentage of the larval population to be living and surviving the unfavourable dry or winter season in underground breeding sites.Service pits and manholes have been found to contain mosquito larvae.The presence of natural predators of mosquito larvae such as Mesocyclops (Crustacea, Copepoda) species is known to considerably reduce mosquito breeding in service pits and manholes.