Resistance to insecticides in the field and baseline susceptibility to cyclaniliprole of whitefly Bemisia tabaci (Gennadius) in China

Resistance to multiple insecticides has become the biggest challenge to controlling Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). In attempts to remedy the problem, four insecticides with novel modes of action (cyclaniliprole, cyantraniliprole, sulfoxaflor, and flupyradifurone) have recently been introduced to control B. tabaci. In the present study, we collected 18 B. tabaci populations in China from 2018 to 2019 to determine their resistance levels to six insecticides including the above four insecticides and two representative traditional insecticides (bifenthrin and imidacloprid). The results showed cyclaniliprole with LC50 values ranging from 3.4 to 21.2 mg/L was the most toxic insecticide to B. tabaci field populations and their average LC50 of 13.5 mg/L was used for the susceptible baseline to cyclaniliprole. The other three newly introduced insecticides (cyantraniliprole, sulfoxaflor, and flupyradifurone) also exhibited high toxicity to the field populations, however, the two traditional insecticides tested were of low toxicity with LC50 values ranging from 16.9 to 296.6 mg/L and from 33.1 to 397.0 mg/L for bifenthrin and imidacloprid, respectively. These results demonstrate that the newly introduced insecticides can currently be considered as effective alternative insecticides in insect resistance management programs for B. tabaci in China.