Abstract
In the laboratory, fipronil was tested against laboratory-reared and field-collected early 4th-instars of Aedes albopictus. The insecticide was also bioassayed for activity against natural field populations of Ae. albopictus inhabiting 1-liter-capacity stone-made containers in it cemetery in St. Augustine, FL. The cemetery containers also were Utilized to Study initial efficacy and activity persistence of fipronil against natural populations of Ae. albopictus. The laboratory-reared larvae were 2-fold more susceptible than field-collected larvae as indicated by the 50% lethal concentration (LC(50)) values of 2.6 and 6 parts per billion (ppb) for laboratory-reared and field-collected larvae, respectively. In the field bioassay, in stone-made containers, the LC50 value of Ae. albopictus larvae amounted to 57.5 ppb. In the cemetery containers, fipronil applied at 3.2 and 32 ppb gave 100% control of Ae. albopictus larvae with either rate of application for at least up to 8 wk posttreatment.