Study On The Control Of Two Ixodid Ticks By Essential Oils

Tick is a kind of arthropod that sucks blood in vitro.It is a transmission vector of various pathogens,which causes great harm to human health and the development of animal husbandry.Hyalomma rufipes is a two-host tick,widely distributed in Africa and China's Inner Mongolia,Shanxi,Ningxia,Xinjiang,etc.,and can transmit Babesia,Rickettsia,and Crimean-Congo hemorrhagic fever virus.Haemaphysalis doenitzi is a three-host tick,mainly distributed in Fujian,Yunnan,and other places of China.It can carry a variety of pathogens such as Babesia.In this thesis,Hyalomma rufipes and Haemaphysalis doenitzi were used as research objects.The toxic effect of 9 kinds of plant essential oils on Hyalomma rufipes unfed adults was tested by in vitro immersion method,and the toxic effect of11 kinds of plant essential oils on Haemaphysalis doenitzi unfed adults also was tested.The toxic effect of 9 kinds of plant essential oils on Hyalomma rufipes unfed larvae was also tested by filter paper bag method.And the median lethal concentration(LC₅₀)was measured.Hyalomma rufipes were reared successfully using artificial membrane feeding technology,and the toxic effect of cinnamon bark oil on ticks,biting on artificial membranes,was tested.Meanwhile,the repellent activity of DEET and 15plant essential oils against Haemaphysalis doenitzi unfed nymphs was tested by repellent experiments.Additionally,the components of 23 plant essential oils were analyzed by gas chromatography-mass spectrometry?GC-MS?.The main results are as follows:1.The toxicity of eucalyptus oil,allspice oil,cinnamon bark oil,basil essential oil,rose essential oil,grapefruit oil,cypress oil,geranium essential oil,and marigold essential oil against Hyalomma rufipes unfed adults,three plant essential oils with the significant contact toxicity were cinnamon bark oil,geranium essential oil,and basil essential oil.And the LC₅₀0 was 15.51 mg/ml,24.90 mg/ml,and 26.19 mg/ml,respectively.The toxicity of eucalyptus oil,allspice oil,cinnamon bark oil,basil essential oil,rose essential oil,grapefruit oil,cypress oil,geranium essential oil,marigold essential oil,lemon essential oil,and holly oil against Haemaphysalis doenitzi unfed adults.Holly oil,cinnamon bark oil,and allspice oil had significant contact toxicity,and the LC₅₀0 was 7.97 mg/ml,8.59 mg/ml,and 11.28 mg/ml,respectively.The toxicity of eucalyptus oil,allspice oil,cinnamon bark oil,basil essential oil,rose essential oil,grapefruit oil,cypress oil,geranium essential oil,and marigold essential oil against Hyalomma rufipes unfed larvae.The contact toxicity of cinnamon bark oil,basil essential oil,and marigold essential oil were significant.And the LC₅₀was 8.84 mg/ml,17.73 mg/ml,and 26.12 mg/ml,respectively.2.Hyalomma rufipes were successfully raised by artificial membrane technology.Among 120 Hyalomma rufipes unfed adults,50 male ticks successfully bite,with a attached rate of 83.4%.And 45 female ticks successfully bite;the attached rate is 75.0%.On the basis of this technology,different doses of 0.5?l,1?l,2?l,and4?l of cinnamon bark oil were added to backplane of ticks.Additionally,the lethality of each dose was measured at 30 min,1 h,5 h,and 24 h.3.The repellent activity of thyme essential oil,clove essential oil,holly oil,nepeta essential oil,bitter essential oil,jasmine essential oil,vitex essential oil,lemongrass oil,oregano essential oil,cypress oil,geranium essential oil,cedarwood essential oil,vetiver essential oil,ylang-ylang essential oil,coriander essential oil,and DEET against Haemaphysalis doenitzi unfed nymphs.By comparison with the positive control group DEET,oregano essential oil,thyme essential oil,jasmine essential oil,lemongrass oil,coriander essential oil,ylang-ylang essential oil,and geranium essential oil had significant repellent activity and the value of EC₅₀0 was lower than DEET.The EC₅₀0 of seven essential oil was 2.12 mg/cm²,2.46 mg/cm²,2.97 mg/cm²,4.13 mg/cm²,5.34 mg/cm²,5.68 mg/cm²,6.75 mg/cm²,respectively.4.Gas chromatography-mass spectrometry?GC-MS?was used to analyze the composition of 23 plant essential oils,and it determined chemical components whose relative content accounts for more than 1%of the total components.The above results provide a reference for the development of new,low-toxic,and highly effective anti-tick drugs and repellent drugs,as well as for raising ticks in artificial membrane.