| One of the most important agricultural pests is the Galleria mellonella,a highly destructive insect that attacks and destroys hives,wreaking havoc on the beekeeping industry.Tea tree oil and eucalyptus oil are rich in resources,with insecticidal and sterilizing effects.The evaluation of the insecticidal effect of its active components has a guiding role in practical application.This paper mainly studied the contact activity of several main components of tea tree oil and eucalyptus oil,such as?-terpineol,?-terpineol,terpinolene,4-terpineol,1,8-cineole,mixed essential oil and compound essential oil against the Galleria mellonella.Preparation of nano-emulsion and determination of its insecticidal activity;The activity of mixed essential oil nanometer emulsion on acetylcholinesterase,carboxylate esterase and glutathione-S-transferase was determined.It provides technical support for the research and development of plant pesticides,the green control of agricultural pests and the reduction of the cost of essential oil pesticides.The main research results are as follows:1 Contact toxicity of five active ingredients against Galleria mellonella?-terpineol,?-terpineol,terpinolene,4-terpineol and 1,8-cineole had certain contact activity against the Galleria mellonella,but the insecticidal effect was different.The five chemical substances had a certain dose effect on the contact action of the larva of the Galleria mellonella,and the contact action on the larva of the Galleria mellonella increased with the increase of the concentration.The contact effect of 4-terpineol and 1,8-cineole was the best,and the LD50 of?-terpineol,?-terpineol,terpinolene,4-terpineol and 1,8-cineole to the Galleria mellonella were1953.428 ug/larva,3320.422 ug/larva,2670.531 ug/larva,765.743 ug/larva and765.743 ug/larva,respectively.2 Contact toxicity of mixed formula against Galleria mellonellaIn this paper,the effects of mixed essential oil and mixed essential oil on the contact killing of the giant moth were studied.Compared with single active ingredient,the contact effect of mixed essential oil and compound essential oil was enhanced.There was a significant difference between mixed essential oil and mixed essential oil with different dilution ratio on the toxic effect of the Galleria mellonella,and with the increase of treatment dose,the mortality rate of the Galleria mellonella increased,and the two were positively correlated.The contact effect of compound essential oil was significantly enhanced than that of compound essential oil.The LD50 was 144.327 ug/larva and 433.116 ug/larva,respectively.3.Contact toxicity of essential oil nanoemulsion against Galleria mellonellaThree kinds of essential oil nanoemulsion and essential oil crude emulsion with different ratio were configured,and the formula F3 was found to be the best by particle determination,with the droplet size of 40.8 nm and PDI value of 0.268.The data showed that the particle size and dispersion of the emulsion changed with the change of the surfactant tween 80,and the particle size of the droplets decreased with the increase of tween 80 concentration.The contact activity of the essential oil nanoemulsion was significantly enhanced than that of the bulk emulsion,and the LD50was 28.991 and 514.056 ug/larva,respectively.4.Contact toxicity mechanism of essential oil nanoemulsion against Galleria mellonellaThe nanoemulsion of essential oil had a significant inhibitory effect on AChE and CarE of the Galleria mellonella.With the increase of the treatment dose of essential oil nanoemulsion,the inhibition effect of the nanoemulsion on Ach E and CarE in the body of the giant moth showed an overall increasing trend.Under the maximum treatment dose of 206.16 ug/larva,the inhibition rates of AchE and CarE in the body of the giant moth were 48.81%and 41.92%,respectively,which were significantly different from the control?p<0.05?.There was no significant change in the GST activity dose of Galleria mellonella. |
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