Acaricidal activity of extracts from Adonis coerulea Maxim. against Psoroptes cuniculi in vitro and in vivo.

The acaricidal activity of Adonis coerulea extracts was investigated against Psoroptes cuniculi. The aqueous, methanol, acetic ether and petroleum ether extracts all showed marked acaricidal activity in vitro. Especially, the acetic ether extract possessed strong toxicity against mites in vitro with LT50 values 0.743 h, 2.730 h, 5.919 h and 22.536 h at concentrations of 500, 250, 125 and 62.5 mg/ml, respectively. At the same time, the acetic ether extract showed the best effectiveness topically to infested rabbits in vivo. After three times treatment, at the day 20, rabbits treated with A. coerulea extract were observed only small scabs or secretions in ear canal, but no mites. These findings suggested that as a potential insecticide, A. coerulea should be studied further to develop active components or a new acaricidal drug.