Mosquito Control Agents Derived from Petroleum Hydrocarbons. III. The Effect of FLIT® MLO on First and Second Larval Instars1

Abstract

The petroleum hydrocarbon, FLIT MLO, markedly retarded the development of the 1st and 2nd larval instars of the southern house mosquito, Culex pipiens quinquefasciatus Say (=C. fatigans Wiedmann) , and the yellow-fever mosquito, Aedes aegypti (L.), when applied to the water surface in 11¾, × 7-inch enameled pans at dosage rates of 0.5, 1, 2, and 4 gal per acre. Maximum delay in development and maximum mortality were obtained at the rate of 2 gal per acre, which delayed the onset of pupation as much as 9 days and prolonged larval development for as long as 42 days. Gross and microscopic observations of “stunted” specimens revealed abnormalities in the tracheal system, alimentation, pigmentation and response to external stimuli.