Preparation And Application Of Combinations Of Metarhizium Brunneum And Insecticidal Drugs

Metarhizium brunneum,as a broad-spectrum entomophagous fungus,has been widely used in the prevention and control of various agricultural insect diseases.It is one of the representative species of entomophagous fungi,but the current research on its control to animal ectoparasites is very scarce,which hinders the application of the fungus in the prevention and control of veterinary parasitic diseases.In order to promote the application of M.brunneum in the biological control of livestock parasitic diseases,it is necessary to carry out the research,especially the development of biocontrol agents.To this end,this article took M.brunneum as the test fungus,on the basis of the research of batch culture method in the laboratory,and the virulence to musca domestica at different developmental stages was determined,the optimum spore concentration was selected,then a wettable powder of M.brunneum was developped.After studying the interaction with beta-cypermethrin,a collaboration with beta-cypermethrin was prepared.Latter,the store conditions,germination rate,wetting time,spore suspension rate,UV protection effect,particle size,p H and other properties of the preparation were measured.Meanwhile,the preparation was used to control flies on the cattle farm.The experimental results were as follows:（1）The determination of optimal virulence to domestic fly larvae,pupal,and adult flies were 1×10⁶/m L,1×10⁷/m L and 1×10⁶/m L.Using spore germination rate,colony growth diameter,spore yield and hyphal biomass as the indicators,it was determined that there was no significant effect of beta-cypermethrin on the growth of M.brunneum.（2）The combination of M.brunneum with low-dose beta-cypermethrin showed that the preparation had different degrees of median lethal time(LT₅₀)was shortened and increased lethality rates in various stages of houseflies at all stages of development.At optimal conidia concentrations,the rate of housefly larvae LT₅₀was shortened from101.81h to 85.72h and the mortality rate increased from 86.7%to 100%,the housefly LT₅₀was shortened from 161.64 h to 129.81 h,and the mortality rate increased from 53.0%to66.7%,and the LT₅₀of adult flies was shortened from 126.03h to 102.60h,and the mortality rate increased from 70.0%to 83.3%.Adding a lure agent to the original M.brunneum wettable powder of 3%fish protein,can increase the effect of M.brunneum wettable powder on the prevention and control of houseflies in practical applications.The wettable powder prepared by the test could meets the national standards and provides technical support for the clinical application of the agent and the biocontrol control of parasites in livestock.3)In the experiment on the cattle farm,the prevention and control effect of M.brunneum wettable powder,beta-cypermethrin wettable powder,and M.brunneum-beta-cypermethrin combined preparation on housefly larvae,pupae and adult flies was carried out,which confirmed that the above two biocontrol preparations had different degrees of prevention and control effect on houseflies,and the control effects on housefly larvae and pupae within 7 days were 61.2%,49.3%and 76.1%,respectively,and the control effects on adult domestic flies were 64.0%,80%and 84.0%,respectively;the effect of the lure-type brown zombie wettable powder was further improved in the lure test,and the mortality rate of adult houseflies was greater than 86%.The above experimental conclusions laid the foundation for the use of M.brunneum in animal husbandry.In summary,the biocontrol preparation M.brunneum wettable powder,M.brunneum-beta-cypermethrin combined preparation,lure M.brunneum wettable powder prepared by the test could play impotant role in veterinary clinics,and contribute to the use of biological control of veterinary parasitic diseases.It was also determined that the combination of M.brunneum and beta-cypermethrin had a certain synergistic effect,which might make up the shortcomings of the slow action of biocontrol preparations,and provide a new choice for the prevention and control of veterinary ectoparasitic diseases.Besides it also may lay the foundation for the further research and clinical application of the fungus in the future and has certain significance for the healthy development of livestock breeding.