Research On The Correlationships Of Beauveria Bassiana Control Hegesidemus Habrus

Hegesidemus habrus Drake belongs to Hemiptera Tingidae Tinginae,a piercing insect pest that feeds mainly on the leaves of willows and other trees.Both adults and nymphs are harmful to feeding.At the same time,it also increases the incidence of coal smudge and seriously affects the growth and development of trees.At present,there have been a lot of studies on the control of the insect,mainly physical and chemical control,but there has been no report on the use of biological control and the use of Beauveria bassiana control.Firstly,a field survey was conducted on the damage of Hegesidemus habrus Drake in Taigu County,Shanxi Province.Later,in order to solve the problem of insect origin for research,the laboratory study of Hegesidemus habrus Drake was carried out.He toxicity of four species of Beauveria bassiana to Diprionidae larvae was tested.Finally,one strain with high toxicity to Hegesidemus habrus Drake was selected from four existing strains by body wall smearing.At the same time,toxicity tests at different concentrations and temperatures were carried out to screen out the optimum concentration and temperature.The specific results are as follows:（1）In Taigu County,willow is the main type of garden plants endangered by Hegesidemus habrus Drake,and weeping willow and dry willow are both endangered,relatively speaking,weeping willow is more serious.The maximum number of Hegesidemus habrus Drake in weeping willow was 3109 per louver,while that in dry willow was 1011 per louver.At the same time,the number of insect population in different directions was counted.The results showed that the number of insect population in the South was the largest,with 1835 per louver（2）the paper tried to select five kinds of vegetables for indoor rearing Hegesidemus habrus Drake.Results that All survived,and the survival rate showed a downward trend with the passage of time.The results showed that breeding effect of celery leaves was the best and the average survival rate was the highest,reached 93.33%.The average survival rate of sweet potato leaves was the lowest,was only 78.33%.Through a significant difference in survival rate and comparison with nutrient components,it was found that the trend of water change consistent with survival rate,and ash was opposite to survival rate.It is speculated that the main criterion for selecting new hosts is water content.（3）At the same concentration,four kinds of strains about Beauveria bassiana were identified,embraces FDB,JLYT,BF and TST.The results showed that the insect body changed from the original light yellow to white,somatic mesoblast was softer than the control,and the puncture was easier.Some insects appeared black spots of the size of pinholes,and their activity was reduced after being infected by fungi.The number of blood cells increased first and then decreased,which proves that Beauveria bassiana spore suspension have pathogenic to Diprionidae.（4）The objective of this study was tested for the pathogenicity effect of Hegesidemus habrus Drake at four kinds of inoculation concentration of 1×10⁸ conidia/m L.It was observed that four kinds of bacteria were pathogenic to the test insect.The result showed that the mortality rate was rank above 90% ahout bacteria of BF and FDB.The mortality rate of FDB was the highest to 92.22%,bombys batryticatus rate was 74.11%.The mortality rate of BF was 91.11%,bombys batryticatus rate was the highest to 84.44%.The LT₅₀ of the strains of BF and FDB were less then 4 d.BF was the most quickly to 2.33 d.Take all factors into consideration,BF was the best one.The bacterial solutions of different concentrations were 1 *10⁶,1 *10⁷ and 1 *10⁸ mL^-1,made from high virulent strain BF.The same way was used to infect Membrane-shoulder Reticulator after Tween-80 solution was used as control.Get the regression equation y=15x+45.553（R²=0.9068）,and get LC₅₀=2.97×10⁵m L^-1.（5）The result of BF temperature experiments showed that the mortality rate was rank above 90%at 22,26 ℃,and the mortality rate was up to 100%.So,the best range of temperature is 22-26 ℃ to splash liquor,increasing or lowering the temperature all will decrease the infection rate.In this paper,the feasibility test of the biological control of the rhizomes is first performed by entomogenous fungi.The results showed that the death of the test insects was caused by the infection of bacterial fluid,which confirmed that temperature was one of the main factors affecting spore germination...