Scleroderma Sichuanensis Carrying Beauveria Bassiana Microcapsules To Control Monochamus Alternatus

Since the invasion of pine wood nematode disease in China,588 county-level administrative regions have been classified as pine wood nematode disease areas,and pine wood nematode disease has caused serious damage to China’s economy and ecology.Monochamus alternatus is one of the main vector insects of the spread of Bursaphelenchus xylophilus,so the control of M.alternatus can effectively control the spread of pine wood nematode.Research practice at home and abroad shows that the use of natural enemy insects and entomogenous fungi to control M.alternatus is a useful measure.In this experiment,the growth traits of 6 different strains of Beauveria bassiana and the virulence of M.alternatus were compared.The best pathogenic strains were mixed with 3 kinds of polymer materials to prepare microcapsules,and the preparation was determined.Under the premise of parameters,the germination rate of spores of B.bassiana and the sporulation of different microcapsules,the adhesion on the surface of Scleroderma sichuanensis and the infective effect of the indoor on M.alternatus were compared.The B.bassiana microcapsules with the best infestation effect were applied to the forest control experiment.The conclusions are as follows:1.The growth rate of 6 strains of B.bassiana was compared.On the 21st day,the largest colony diameter was B₂strain,the smallest was B_g2strain,48.04 mm and 32.36mm respectively;the The most strain sporulation was B₂strain,and the least was B_g1strain.,3.86×10⁷cfu/cm ²and 1.82 cfu×10⁷cfu/cm ²respectively.Six strains of B.bassiana were inoculated at the larvae of M.alternatus.After 15 days,The two strains with the highest mortality and infection rate of M.alternatus were B₂and B₁,and the lethal rates were 95%and 85%,respectively.The rates are 90%and 75%,respectively.After comprehensive comparative analysis,strain B₂isolated From the susceptible larvae of M.alternatus was superior to other strains in growth traits and pathogenicity to M.alternatus,so B₂strain was identified as the strain used in the subsequent experiments.2.Preparation of B.bassiana microcapsules.After comparing different preparation conditions,the optimal preparation scheme of different wall materials was determined.After comparing the microcapsule particle size,spore powder content and spore germination rate prepared by the acute pore solidification method and the complex phase emulsion method,alginic acid was used.The sodium microcapsules have a particle size of 22.7μm,a spore powder content of 9.95 cfu/particle,a spore germination rate of 77.88%,a surface adhesion rate of 63%on the S.sichuanensis,and a 60%infection of the M.alternatus in an indoor test.The comprehensive performance of the microcapsule was determined to be used as a microcapsule for the forest control trial.3.Forest control trials.Through the calculation of the reduction rate and control effect of various insects,the population loss rate of each sample of M.alternatus was41.88%,53.59%and 4.03%,respectively;the correction reducing rate of sample 1 and sample 2 was 39.44%,respectively.And 51.65%,indicating that the release of the B.bassiana microcapsules of the S.sichuanensis has a better control effect on the M.alternatus than the single release of the S.sichuanensis.Through this experiment,it is proved that the use of natural enemies to carry pathogenic fungi microcapsules to control the wood borer has certain reference and reference value for the prevention and control of large wood borer such as Batocera lineolata.