Distribution and control of Chironomus riparius (Diptera: Chironomidae) in a polluted creek

Mass emergences of adult Chironomus riparius have been regularly occurring in late February near residential areas adjacent to a creek receiving municipal sewage effluent located in Lexington, Kentucky. Prior to attempting control of this chironomid, the larval distribution of this species in the creek was investigated. Although large numbers of larvae were being produced in this creek, the greatest larval density occurred downstream from an adjacent horse "muck" pile and an adjacent landfill. Application of Vectobac-6AS reduced larval density in these areas but Vectobac-G did not.