The Defense Effect Of Stratiolaelaps Scimitus On The Infection Of Beauveria Bassiana

With the extensive use of traditional chemical pesticides,the resistance of pests has gradually increased,and biological control has gradually attracted more and more people's attention.However,some natural enemies sometimes do not have good control effect over the entire life history of a single pest.In order to improve the effect of biological control and reduce unnecessary economic losses,the combination of various natural enemies is a hot topic in modern biocontrol.However,due to the synergy between various natural enemies,there may be predation or parasitic effects,antagonism and the relationship between natural resources and competition is therefore highly controversial.Especially for insecticidal broad-spectrum entomopathogenic fungi,it also has a potential risk of infestation to natural enemy insects while killing pests.Therefore,the evaluation of compatibility is sues between multiple natural enemies has become the key to the success of joint applications.Based on the existing observations and researches,this paper studies the defense of a terrestrial predator,Stratiolaelaps scimitus,against B.bassiana from the perspectives of its biology,behavior and epidermal physical defense.The compatibility relationship between S.scimitus and B.bassiana was evaluated.The main conclusions were as follows:1.The effect of B.bassiana on the survival rate of S.scimitus:whether it is eggs,larva,protonymph,dcutonymph and adults,the survival rate of S.scimitus treated by B.bassiana at all ages had no significant difference with the control group treated with Tween-80.Observed under a dissecting microscope,it was found that the hydatid did not grow on the corpse of the S.scimitus after 5-6 days of death,indicating normal death.It indicated that B.bassiana had no effect on the survival rate of S.scimitus at any age.Effect of B.bassiana on the immature stage of the S.scimitus:The S.scimitus was treated with B.bassiana at each age of the adult mites,and it was found that compared with the treatment group and the control group.There was no significant difference in the developmental time of the age.It indicated that B.bassiana could not affect the growth and development of S.scimitus in the immature stage.Effect of B.bassiana on the reproduction and longevity of female adult mites:The time of pre-and post-spawning period of the female mites,and the average number of eggs laid until the death was recorded.By comparison with the control group,the average time of spawning and the average egg production and the average life span of the treatment group were almost the same as those of the control group.So it is considered that B.bassiana does not have a physiological effect on it.2.B.bassiana granule experiment:The experiment of B.bassiana granules was carried out after the small-cell blasting experiment was carried out on each age of S.scimitus to prove that B.bassiana had no effect on it.And the population of the genus S.scimitus is still not affected by the granules of B.bassiana.3.S.scimitus showed behavioral defense against B.bassiana:In order to better determine the behavioral defense of S.scimitus against B.bassiana,the predation selectivity of infected thrips and non-stained thrips was carried out.experiment of.It was found that under the same temperature and humidity conditions,S.scimitus tends to prey on the thrips after the infection,and the number of snails that prey on the infected thrips is significantly higher than that of the non-stained thrips.4..S.scimitus showed a protective effect on the epidermis of B.bassiana:Scanning electron microscopy was performed on the S.scimitus treated with B.bassiana.It was observed that although some B.bassiana spores could attach and germination on the epidermis of S.scimitus,they only extended the epidermis and could not penetrate the epidermis.The role of the epidermis component of S.scimitus in the defense against B.bassiana:after the detection and analysis of the epidermal components,combined with the existing research reports,it shows that the epidermis of S.scimitus is resistant to the white mushroom invasion.The dyed ingredients belong to the alanine of short-chain fatty acids,as well as galactose,octadecatrienoic acid,glycerol and sarcosine.