| The European red mite, Panonychus ulmi (Koch)(Acari: Tetranychidae), is one of the primarypests in the apple orchard and causes serious damage. In order to understand resistance levels ofdifferent apple varieties to P. ulmi and provide a theoretical basis for conducting integrated pestmanagement (IPM) to P. ulmi, The methods of laboratory experiments and construction of life tableswere used to study the population dynamics of P. ulmi on different apple varieties, and the resistancelevel of different apple varieties were preliminarily identified, and analyze the reason for the differencethrough age-stage two-sex life tables. The research results are as follows:1The investigation of population dynamics of P. ulmi on different apple varieties in the laboratoryThe same number of P. ulmi were moved to the different potted apple seedlings under laboratoryconditions at20-35℃. The growth dynamics were investigated respectively. The results showed thatthere were significant differences in the occurrence of P. ulmi on various apple varieties, which wasserious on Fuji (21.15individuals/leaf and Qinguan (19.07individuals/leaf), and relative less on GrannySmith (11.77individuals/leaf), Gala (11.11individuals/leaf), Tsugaru (9.34individuals/leaf) and Dwarf(4.19individuals/leaf).2Construction and analysis of age-stage two-sex life tables of P. ulmi on different apple varietiesAge–stage two-sex life tables of P. ulmi were constructed and analyzed at23±1°C,75±5%relative humidity and a photoperiod of16:8(L:D)and the results indicated that different apple varietieshave a significant influence on the development time and reproduction of P. ulmi while s lightly affectedthe immature survival. Judging from the intrinsic increase rate we can found that the highest r were onQinguan(0.1513) Fuj（i0.1491）, Golden Delicious（0.1489） and Qionajin（0.1486）, the second higheston Ralls（0.1436）, Granny Smith（0.1359）, Gala（0.1359） and Starkrimson Delicious（0.1357）,and the lowest on Tsugaru（0.1086） and Shandingzi (0.0904). The intrinsic increase rate is the mostimportant parameter for measuring the population increase and the identified results from the twomethods are in agreement. |
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