Our research included degradation of imidacloprid (Premise®) at 50, 75 and 100 ppm; fipronil (Termidor®) at 60, 95 and 125 ppm; and bifenthrin (Talstar®) at 60, 90, 120 ppm in loamy soil. The treated soil samples were incubated at 25 oC and 25% (±3) RH in growth chambers. The insecticide residues extracted from soil and analyzed with HPLC at 0, 8, 30, 60 and 90-day intervals. Data revealed that after 90 days, the residue remained at 60, 85 and 90% of 50, 75 and 100 ppm of imidacloprid, respectively. The residues of fipronil were at 80, 90, and 95% of 60, 95 and 125 ppm, respectively. At the same time interval, we detected bifenthrin at 60, 86 and 95% of 60, 90 and 120 ppm respectively. At zero interval and with highest concentration, the bioassay data produced 100% mortality of subterranean termite workers within 2, 10 and 13 hrs for bifenthrin, fipronil and imidacloprid, respectively. Based on these data, the degradation rate is directly proportional to the concentration of termiticides applied initially in the soil.
Species 1: Isoptera Rhinotermitidae Reticulitermes flavipes (eastern subterranean termite)
Keywords: Insecticides, Persistence
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA