Study On Biology Character Of Panonychus Ulmi Experiment Population And Its Field Pendulum

Recently ,panonychus ulmi occur badly in the apple pear garden of Yan Bian area. In order to integrated prevention it .This paper study its shape character by observation in lad and field . Experiment is carry out under five temperatures and calculate the development threshold temperature and efficiency accumulate temperature. Build the experiment population life table of panonychus ulmi under five temperature .The result as follows:1) The color of summer egg is nacarat or ivory-white. The development phase of male mite is same with female mite.2) The development threshold temperature of panonychus ulmi egg is 7.79℃,efficiency accumulate temperature is 113.49 and the whole generation is 9.78℃, and 202.16.It occur five or six generations one year in YanBian area (beside the overwintering generation) .3) Panonychus ulmi imago life expectancy shorten along with temperature rise(such asl8℃ is 15.15d and 34℃is 5.96d) .The quantity of average lay egg quantity of lifetime on 26℃ is the bigger(45.65 granule).4) Under photophase 16h/d .The result :net reproductive rate is the bigger on 26℃ (25.9591) ,intrinsic rate of natural increase is the bigger on 29.28℃(0.2392) ;finite rate of increase is augment with the temperature rise, it decrease when temperature is 34℃ ;population double time decrease rapid with temperature rise in the section of low temperature, it postpone when temperature is 34 ℃, average generation time increase with temperature assume exponent.5) Panonychus ulmi occur two flood tides in field in one year. The first flood occurs from the middle of June to the end of June and the other in the middle of August. The first duration is longer and the quantity of mite is bigger.