Experimental Life Table for Population of Amblyseius swirskii(Athias-Henriot)Fed on Tetranychus truncatus(Ehara)

The parameters of a life table with an experimental population of Amblysieus swirskii(Athias-Henriot)were studied.At 6 constant temperatures(i.e.,15℃,18℃,20℃,25℃,30℃ and 35℃),A.swirskii were fed on Tetranychus truncatus(Ehara)to evaluate the feasibility of utilizing the predatory mites to control the spider mites.The in-laboratory experiments showed that,at 15℃,the predatory mite could develop,but its survival rate was less than 43.33%,and there were irregularities observed in its egg-laying.The temperature range of 18-35℃ was considered appropriate for the predatory mite's development.And,within the range,the time for A.swirskii to develop shortened as the temperature rose-the longest(31.50 days)at 15℃ and shortest(5.75days)at 35℃ for the females,and the longest(20.00 days)at 15℃ and shortest(3.96 days)at 35℃ for the males.The highest intrinsic rate of natural increase(rm = 0.1976)and the highest finite rate of increase(λ=1.2185)were observed at 35℃.The highest sex ratio(1.73:1)and the highest net reproductive rate(R0=36.8600)were found at 25℃.And,the highest mean number of eggs(57.60 eggs per female)occurred at 25℃.