Toxicity of conventional termiticides to Reticulitermes flaviceps.

Objective To evaluate the toxicity and repellent effects of 20% Tianying termiticidal emulsifiable concentrates,5% bifenthrin suspension concentrates,15% Wanjie termiticidal emulsifiable concentrates and 48% chlorpyrifos emulsifiable concentrates to Reticulitermes flaviceps,providing the basis for termite control.Methods The drug-impregnated filter method,toxic soil method and toxic soil pillar method were used to determine the toxicity and repellent effects of the four agents against R.flaviceps.Results Among the four tested agents,48% chlorpyrifos emulsifiable concentrates and 5% bifenthrin suspension concentrates had the greatest contact toxicity to R.flaviceps.After 30 min of exposure to filters impregnated with 200 mg/L of them,the termite mortality reached 100% beyond 48 h.The second most toxic agent was 20% Tianying termiticidal emulsifiable concentrates,with 100% mortality beyond day 11 after treatment.The Wanjie termiticidal emulsifiable concentrates had the lowest toxicity to termites,with only 46.7% mortality beyond day 11 after treatment.All of the R.flaviceps in contact with the soil treated with ≥20 mg/L of any of the four agents died in 1 to 8 d.At a concentration of ≥200 mg/L,none of R.flaviceps could penetrate through a soil layer of 5 cm in thickness.Conclusion All of the four tested drugs can be used for termite prevention.In general,however,20% Tianying termiticidal emulsifiable concentrates should be the agent of choice for the manufacturing industry.