The Solid Fermentation Of Beauveria Bassiana And Study On Virulence For Vegetable Pest

In this paper, the insecticidal spectrum, industrialized solid compost, carrier, culture condition, virulence and the compatibility between Beauveria bassiana and chemical pesticide were studied on Beauveria bassiana strain Bb98.The purpose was to find the weaknesses of Beauveria bassiana as a biological insecticide and provide a scientific basis for the large-scaled industrialized production of Beauveria bassiana.The insecticidal spectrum and insecticidal effect of Beauveria bassiana were tested on strain Bb98 and new isolated strain Bb01 and Bb02.The results indicated that Beauveria bassiana was effective to the insects of Coleoptera, Lepidoptera and Homoptera, including the larva of Plutella xylostella, Pieris brassicae, Borabyx mori(L.),Prodenia Litura(Fabricius) Lipaphis erysimi(kaltenbach),and adult of Piodia Interpunctella and stitophilus zeamais. Among the three orders ,the effect to the Lepidoptera was the best and the effect to the Homoptera was the second. The effect to the larva was better than to the adult. The strain Bb01 isolated from Bombyx mori(L.)was more effective than strain Bb98 to Bombyx mori(L.) . The influence of Beauveria bassiana to death, pupation and eclosion of the insects could be found in the tests.The solid compost of Beauveria bassiana was studied. The results showed that the sporulation in liquid media with 30% of the solid media was the best. A,B and J were the best three prearations. In the respect of soil samples, the effect decrease in the following sequence: pondsoil, gardensoil, contaminative soil.The prearation with fertile soil was antipolluted. The improvement of culture methods showed that the sporulation was higher in bag than in bottle .The reason might related to the ventilation. The productive methods of Beauveria bassiana were also simplified , the results would benefit to the popularization and application of Beauveria bassiana.Ten different carriers were filtered by mensuration of germination rates of spore, sporulation and growth mycelial. Cluster analysis and variance analysis showed that wheat bran, sawdust, Diatomaceous earth (DE )3, DE4 were suitable to be the carriers of Beauveria bassiana.The effects of 8 kinds of chemical pesticides to the growth mycelial and germination showed that all the 8 chemical pesticides inhibited them to a certain degree . The higher concentration was , the stronger inhibition was. The correlation was linear. Based on the tests, Beauveria bassiana could be used with Phoxin,Deltamethrin,Bt, Chlorpyrifos and DDV in certain concentration.It may be worth studying further.11 kinds of nitrogen sources, 7 kinds of carbon sources and 16 different C:N were studied on culture medium SDAY. The results indicated that sporulation and toxicity in nitrogen sources from animal were higher than in nitrogen sources from plant, inorganic nitrogen sources couldn't be used absolutely. The beef was the best nitrogen sources. Availability and toxicity were different in different carbon sources. Ethanol couldn't be used absolutely. Glucose was the best carbon sources.The parameters in prearations with different C:N lacked significant tendency while the effect decided by quantity of nitrogen sources and carbon sources. Correlation analysis showed that the correlation between sporulation and toxicity was higher than correlation between growth mycelial and toxicity. Growth mycelial and sporulation lacked significant tendency, but correlation between sporulation and toxicity in different treatments with the same strain was prominent.