Control of the Dark Rice Field Mosquito with FLIT® MLO12

Abstract

Small-plot and outfield tests were conducted to determine the amount required and best method of FLIT® MLO application to control Psorophora confinnis (Lynch-Arribalzaga) in Louisiana. Larval mortality was determined 24 hours following application. At the 0.5 gal/acre rate, the spray and pour-on applications of the material caused 97% mortality to first-stage larvae, while the drip-bucket and capsule applications effected 94 and 90% mortality, respectively. In small-plot tests, the film caused 96% or greater larval mortality at the 2.0 gal/acre rate regardless of the method of application. Spray and capsule application of the material at 0.5 gal/acre resulted in 99% larval mortality in the outfield tests, while 1.0 gal/acre rates were necessary to achieve the same degree of control with the drip-bucket and pour-on methods. The yields of rice in 1968 and 1969 for each method and rate of application indicated that no reduction occurred through use of the surface film. FLIT MLO was not detected in rice grain or straw from plots which had been sprayed with 2.0 gal/acre. An LC50 of 0.34 gal/acre equivalent and an LC90 of 0.53 gal/acre equivalent were determined for P. confinnis pupae.