The Change Of Nymph Body Temperature Of Locusta Migratoria Manilensis And The Pathogenesis Effect On It Of Metarhizium Anisopliae

The Locusta migratoria manilensis(Meyen)is one kind of important pests about harming gramineous plants.There have a series of problems depending on the long-term chemical pesticide against locust.In recent years,the people gradually make use of biological methods instead of chemical methods against locust,especially Metarhizium anisopliae pathogenic Fungi,etc.Normally the effect in the laboratory is better than the field against locust by biological pesticide.The major reason factor is the thermoregulation of locust about the bad effiency in the field.And the themoregulation is not only improving its immune,but also restraining the conidia of Metarhizium anisopliae growth and germination.In this paper,we tested the Locusta migratoria manilensis body temperature regularity in the field,and in laboratory used oil metarhizium anisopliae var acridum of commodity biological pesticide against the 3rd instar locust at different temperature.The aim is to understand the relationship of the locust body temperature and environment factors in the field and the effiency of commodity biological pesticide against the 3rd instar locust in the laboratory.The main results of the paper were summarized as follows.1.The locust body temperature rises with the environment temperature.In daytime,the body temperature has maximum value at 11 a.m and 2 p.m.However,the body temperature occurred the minimum value at 3 a.m.And the highest locust body temperature can get 49?,but the lowest is 23.7?.The summer locust body temperature rises with the increase of the locust instar,but the autumn locust body temperature at every locust instar is no significant difference.2.The related degree about the locust body temperature and the environment factor: ground temperature(0.704)> the middle temperature of plant(0.631)> air humidity(-0.607)> the top temperature of plant(0.603)> ground humidity(-0.597)> air temperature(0.546)> plant height(-0.287)> wind speed(0.142).We got the optimal the linear model through multiple linear regression analysis,the linear regression equation Locusta migratoria manilensis body temperature(Y)and ground temperature(X1)?air humidity(X2)?plant height(X3)?the top temperature of plant(X4)?wind speed(X5): Y=35.096+0.206X1-0.168X2-0.032X3+0.137X4+0.043X5(R2=0.622).Thus,ground temperature(X1)?air humidity(X2)?plant height(X3)?the top temperature of plant(X4)?wind speed(X5)are the major factors influenced the Locusta migratoria manilensis body temperature(Y).3.To test the pathogenesis of oil Metarhizium anisopliae of the commodity biological pesticide of the 3rd instar locust at five gradient temperature(15?20?25?30?35?)and the infected rate of dead locust condition atdifferent five temperature.There is different between locust mortality and infected rate at different temperature.The highest mortality of the temperature is 30?.The infected rate is higher at 25? than any other temperature.Therefore,30? is the optimum temperature of killing the locust with metarhizium anisopliae var acridum,but 25? is the optimum temperature growth of metarhizium anisopliae var acridum.4.The total food consumption and the difference of body weight of the 3rd locust rised with the increase of the temperature.The approximate digestion rised with the increase of the temperature,and the treatment approximate digestion of 15? is negative value.The food conversion rate of 3rd instar locust is highest at 25?.Thus,the 15? restrains the infected 3rd instar locust approximate digestion,nevertheless the 25? has dominant influence on the food conversion rate of 3rd instar infected locust.