Biological Activity Effect Of 15 Essential Oils Against Aedes Albopictus

With the warming of the climate and the deepening of global trade,Aedes albopictus has accelerated its spread throughout the world,what followed was the outbreak of diseases in which Ae.albopictus acted as a transmission medium.Thus the development of safe and effective mosquito repellents and poisons has become a hot spot.In this paper,15 common woody ornamental plants are selected,and essential oils are extracted through a laboratory-made oil extraction device.The composition of the 15essential oils was analyzed by GC-MS and the main components contained in each essential oil were obtained.The effects of 15 plant essential oils on Ae.albopictus larvae were tested by immersion method.The flask method was used to determine the fumigation activity of15 plant essential oils on adults of Ae.albopictus.The EAG response of Ae.albopictus to essential oils was determined by an antennal potential instrument.According to the national standard method,the repellent activity of 15 plant essential oils on female adults of Ae.albopictus was determined.And the biological activities of these essential oils on the growth stages of Ae.albopictus were obtained.Combining essential component analysis of essential oils,it will provide data and theoretical basis for the prevention and control of Ae.albopictus with plant essential oils.This will provide materials for the future exploration of new plant-derived mosquito repellents and mosquito insecticide.The result shows:1)There are many similarities in the composition of 15 plant essential oils.Terpenes,aliphatic hydrocarbons,aromatic alcohols and other compounds are the main components of these 15 plant essential oils,and the same plant essential oil may have multiple isomeric structures;2)All of these essential oils have good killing effect on larvae,and can achieve 100%lethal effect at 1%concentration.Age showed great impact on the killing effect of essential oils.Oils from Aceraceae,Pinaceae and Cupressaceae have better poisoning effect on larvae.The toxic effects of Cinnamomum bodinieri Levl.oil,Michelia macclurei Dandy,Pinus Elliottii,and Juniperus formosana Hayata are relatively good,while the poisoning effects of Taxodium distichum(L.)Rich.and Michelia chapensis Dandy are relatively stable,and the thick texture of Michelia chapensis Dandy oil is likely to affect its poisoning effect and reduce its poisoning efficiency.3)The response of DEET was not strong as expected in the electroantennogram response.There are many varieties of EAG in the test essential oil which exceed the DEET.The sensation of the antennae in the three essential oils of Lauraceae is greater after 1%concentration,changes in the first few concentration gradients did not bring significant changes in antennae potential;Michelia macclurei Dandy oil in Magnoliaceae shows better antennae potential response,EAG relative response increased with increasing concentration.Michelia chapensis Dandy oil is at a lower and slowly rising level,but Magnolia grandiflora EAG is basically no law,large fluctuations,the relative value is also lower;The relative values of Cryptomeria fortunei Hooibrenk ex Otto et Dietr oil and Taxodium distichum(L.)Rich oil are higher than those of DEET,After 5%,concentration began to fluctuate,the response of the Taxodium distichum at higher concentrations became stronger;among the three plants of Pinaceae,the lowest relative EAG response value showed up under the Pinus elliottii oil,the relative EAG response value of Pinus massoniana oil was initially strong,starting at 0.05%,it was lower than that of Pinus taeda oil;the relative response value was also very weak,lower than DEET.The relative response value of EAG cedar essential oil was higher than that of DEET 0.5%-1%.4)The repellent effects of 15 plant essential oils on the female Ae.albopictus were significantly different.At the concentration of 1%,the repellence rate of 5 essential oils was higher than 2 h.The best is Michelia chapensis Dandy,able to achieve an average repellent duration of 3.7 h,and at this concentration of DEET Tween solution only 3 h repellent time.At the 10%concentration,the 3 essential oils of Aceraceae plants exceeded the repellent duration of 2 hours,and Cryptomeria fortunei,Juniperus formosana Hayata,and Magnolia Grandiflora Linn also showed a significant increase,while Cinnamomum bodinieri Levl,Cinnamomum venetum,and Michelia chapensis Dandy showed a downward trend.At 100%concentration,Taxodium distichum(L.)Rich.oil,Pinus elliottii oil,Pinus taeda L.oil,Cupressus funebris Endl.oil,and Michelia crassipes Law oil still maintained a 100%repellent duration of 2 hours.At this concentration,Cinnamon and Michelia chapensis Dandy have the best repellent effect,but both not as good as DEET.Through the repellent schedule,it can be found that the repellent effects of Cinnamomum cassia,Pinus massoniana,Michelia acuminata,and Michelia chapensis Dandy oil are relatively good in 15 essential oils;5)In the adult female fumigation test,Juniperus formosana Hayata and Cupressus funebris Endl.oils had good effect of fumigation,and the LC₉₅ of 10 plant essential oils was lower than that of pyrethrin.Cinnamomum bodinieri Levl.oil,Linn oil and Cryptomeria fortunei oil performed the worst fumigation effect,their LC₅₀ and LC₉₅ are very high,and the effects of several other essential oils are comparable.In summary,these 15 plant essential oils have the potential for the development of plant-derived mosquito repellents and poisons,and their specific components and physical properties can be further studied.