| AbstractIn this thesis, the effect of temperature on the biological characteristics of 2 Metarhizium anisopliae isolates, LA and LD, was studied. Thermoregulation characteristics of Locusta migratoria manilensis(Meyen) as well as its effect on pathogenesis of M. anisopliae was investigated.The most suitable temperature for the 2 isolates colony growth and conidia production was ranged from 25℃to 30℃. Within this range, LA began to produce conidia on the 3rd day and the amount reached 6×107 /cm2, but LD began to produce conidia on the 7th day and the amount was 1×107 /cm2．For the 2 isolates, conidia both germinated fastest at 30℃and GT50s were 7．55h and 9．88h, respectively. Both the two isolates produced most protease protein at 35℃. For chitinase, the most protein was produced at 25℃in LA and 30℃in LD.L. migratoria manilensis had high thermoregulation ability and could absorb radiation heat to regulate body temperature. The thermoregulation ability increased as ages. When the ambient temperature was low, the body temperature could be regulated to a higher level but when the ambient temperature was too high, the body temperature could be regulated to a lower one to avoid being harmed. L. migratoria manilensis was sensitive to high temperature and the high temperature tolerance ability increased with age, too.With thermoregulation, the M. anisopliae infected locusts could prolong the dead time and it was more efficient at higher radiation. Isolate LA still had virulence ability at high temperature, but LD rapidly decreased. The virulence ability of LA was higher than LD. At lower conidia concentration, thermoregulation had higher effect on it s virulence. The infected locust individuals preferred higher temperature for their body temperature rose 1．5℃which was significantly higher than uninfected ones. In the infected locusts, hemocyte concentration decreased rapidly inside those individuals having no thermoregulation ability compared with those ones having or uninfected individuals.
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