| In order to find out socially harmless controlling technologies to white grubs, anddevelop and utilize the resources of entomopathgenic fungi, In these thesis, pathogenicityof several fungal species to the white grubs, biological features, experimental ecologywere studied. And cultivation food in production of fungi were filtered, the examinationof fungi to white grubs in field were studied, and the composited emulsion of fungi andbacteria which saved in house after one year were measured. Some effective techniquesand measures for bring up controlling efficacy to white grubs in the field were proposed.1 Biological experiments of fungal Several species (total 8 strains) were inoculated in differert culture medium anddifferent culture materials, and different temperature was set up. Colony features, growthrate, conidial germination time and conidia output of mycelia were observed in differentculture medium and culture materials. The results indicated that①The Beauveriabrongniartii strain Bbr and Meterhizium anisopliae strain Ma1 and Ma3 can all grow at15℃, 25℃ and 30℃, but the optimum at 25℃. ②The B. brongniartii strain Bbr cangrow well on every medias. Its growth rate is fastest and conidia output of mycelia ishighest in three fungi. Therefore the strain Bbr is more suitable to be produced andapplied. ③Every fungal growth rate are faster and its conidia output of mycelia is higherin culture medium PPDA than others. Therefore PPDA is suitable to grow for fungi. ④The growth of seven fungi except Meterhizium anisopliae and Nomuraea rileyi issuitable to five culture materials. It filled the culture materials only 6-8 days. AndMeterhizium anisopliae growth status was better than others in formulas contain potato(A, C, D), and the D is the best. ⑤The bourgeoning rate of spores of three fungi wasmeasured through being cultivated in liquid nutrition, it showed that the bourgeoningrate of spores of Meterhizium anisopliae was higher than Beauveria brongniartii's in thesame conditions.2 The virulence of socially harmless controlling technologies to whitegrubs in lab The experiments of virulence were made in order to filter strain which highervirulence. The results showed as follows: ①The mortality on the constant temperature(25℃) is higher than on the lower temperature. ②On the lower temperature, urea andMeterhizium anisopliae still have higher controlling effect, thereinto the adjustedaccumulative mortality rates of urea reached at 81.35%. It showed they aren't affected bytemperature. ③The mortality of Bbr is the highest in fungi on constant temperature. Itsadjusted accumulative mortality rates were 86.67% and LT50 8.75 days which is obviousdifferent with others. ④The controlling efficacy to white grubs was enhanced when thestrain Bbr was mixed with Bt and with tee-seed cake. But LT50 of the strain Bbr wasmixed with tee-seed cake was suspended 10 days compared with alone Bbr. It showedthe strain Bbr was mixed with tee-seed cake have enhanced but decreased speed ofmortality. The strain Bbr was mixed with Bt not only have cut down the time of mortalitybut also enhanced the mortality rates.3 Fungus release experiment in the field The strain Bbr, Ma1 and Beauveria bassiana strain 5S03 were selected to release in the fieldthrough the effect of virulence to white grubs in lab. The result showed that the effect of Bbr wasbetter than others. The field dealt with Bbr, the decreasing rates of its quantity of insect and murderedpeanuts and increasing rates of quantity of peanuts was the highest compared with contras. The effectof prevention and cure was 74.18%.4 Measurement of compound latexes of bacteria and fungi saved afterone year Delamination, deposition were appeared in the compound latexes of bacteria andfungi after being stored in house one year. Although pH of each formulation had changed,it ranged from three to seven. The different methods were used for microbial activity's measure. The slab dilutionwas used for bacterial vitality measurement. The live cellular of bacteria quantity can bereflected directly... |
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