Biological aspects of pear bud mite eriophyes pyri (pagenstecher) (acari : eriophidae) under different temperatures in egypt

The pear bud mite or pear leaf – gall mite Eriophyes pyri (Pagenstecher) successfully developed from egg to adult stage when reared on terminal buds of soft apple divided branches dipped in test tubes at different temperatures and 65% R.H., for the first time. The effect of temperature on the development, reproduction and population growth was investigated. At 14 and 34 °C the adults began to slow down and ceased all activity and died. It was able to develop at temperatures between 17 and 29°C with 65 % R.H. inside apple buds. At least of 34 % of the generation time was spent in the egg stage at 29°C. Adult life cycle and longevity decreased with increasing temperature. Fecundity was highest at 29°C with 20.66 eggs per female. Life table parameters showed that the intrinsic rate of natural increase (rm) increased with temperature to a maximum of 0.153 at 29°C. The population of E pyri inside buds multiplied 14.31 times in a generation time of 17.29 days at 29°C and lowered to 4.06 times in a generation time of 23.40 days at 17 °C under the same laboratory conditions.