Kill Ticks Effect Assessment Of Five Kinds Plant Crude Extracts And Screening Of Effective Formulas

Ticks are a kind of ectoparasites with a variety of hosts and global distribution.Ticks parasitism not only directly causes the loss of animal nutrients,skin damage,inflammation and even ulcers,but also spreads a variety of zoonoses and animal diseases,which pose a great threat to the public health livestock industry.In China,the prevention and control of ticks is mainly based on chemical drugs.With the extensive use of chemical drugs for a long period of time,the disadvantages caused by them have become more prominent.With the progress of society and improvement of living standards,people have higher requirement for foods and environment.There is an urgent need for an efficient,environment-friendly and safe method of tick control to replace the extensive use of chemical drugs.Large numbers of studies have demonstrated that botanical acaricidal drugs are one of the methods to solve the current problems.In this study,five kinds of Chinese herbal medicines,namely tobacco leaf,Sichuan chinaberry bark,cnidium monnieri,stemonae radix and flavescens,were selected to screen a new set of plant-derived acaricidal drugs.Firstly,prescriptions of five kinds of traditional Chinese medicine were screened.The five herbs were divided into 31 groups according to 1 Chinese herb,2 Chinese herbs,3 Chinese herbs,4 Chinese herbs,and 5 Chinese herbs respectively.After weighing the herbs,they were soaked,refluxed,and to 1 g/mL to carry out immersion experiment of engorged nymph.Finally two effective arranging prescriptions,tobacco + cnidium and stemonae radix + cnidium,were screened out,and their lethal rates were 96.67% and 93.33%,respectively.Secondly,further research was conducted on the selected effective groups.Weighing,immersing,reflux extraction,and concentrating to 1 g/m L in different proportions of drugs were performed in these groups.In order to study the best proportion of drugs in the traditional Chinese compounds and the effect of the drugs on ticks,two common ticks,Rhipicephalus sanguineus and Boophilus microplus,were selected as experimental subjects.The results showed that the best ratio of the two prescriptions were 1:3(tobacco:cnidium)and1:2(one hundred:cnidium),and the former has the best effect,with 90.00% fatality rate for engorged nymph of Rhipicephalus sanguineus and 80.00% for engorged adult of Boophilus microplus,and spawning rate decreased by 87.61%.This study successfully screened the plant acaricidal drugs for tick control.