STUDY ON OPTIMUM GROWTH CONDITION AND DIVSION OF DEVELOPMENT STAGES OF THE RHYZOPERTHA DOMINICA

In order to accurately know about the damage of the different developmental stages of Rhyzopertha dominicain in stored grain,R.dominicain was reared on wheat (variety aikang 58,which has been stored for 1 year) in climate chambers.The infestation in wheat was determined by staining and split section method,and the optimum growth conditions and different growth stages were studied.The results showed that the maximum R.dominicain inoculation density in wheat was 8 000 adults per kilogaram under 30℃±1℃,75%±2%RH.Under the inoculation density of 8 000 adults per kilogaram and RH 75%±2%,the optimum environment temperature of R.dominicain was 30℃.Under the condition of inoculation density at 30℃±1℃,8 000 adults per kilogaram,the optimum relative humidity of A infestation for wheat was 70%.From the response surface analysis,the inoculation density of R.dominicain was the main factor affecting the infestation rate of wheat,the air relative humidity was the second,and the temperature had the least influence on the infestation rate of wheat.The effect of inoculation density,air relative humidity and temperature on R.dominicain was very significant (P<0.01).The interaction between temperature and humidity,temperature,the density and humidity of the insect and the density of the mouth of the insect is obvious,and the best drop was in the area of the test.The optimum condition for R.dominicain infestation by response surface regressi on analysis was 30.28℃,RH 78% and inoculation density of 8 000 adults per kilogaram.Under the condition,R.dominicain infestation rate in wheat was 90.30% in theory,and the R.dominicain infestation rate was 90.64% by experimental verification.The relative error of the predictive value and the actual result was 0.38%<0.2%,fitting well with the theoretical value,and the value prediction had a reference.Under the optimum conditions,the average growth developmental period of the R.dominicain was 32.64 days,the average developmental period of egg stage,larval stage,pupal stage and adult stage was 6.15,16.56,6.98 and 2.85 d,respectively.