Age-Stage Two-Sex Life Tables of <I>Panonychus ulmi</I> (Acari: Tetranychidae), on Different Apple Varieties

Abstract

To understand the influence of different apple varieties on the development and reproduction of the European red mite, Panonychus ulmi (Koch) (Acari: Tetranychidae), age-stage two-sex life tables of P. ulmi on 'Fuji,' 'Starkrimson Delicious,' 'Golden Delicious,' and 'Granny Smith' varieties were constructed under laboratory conditions at 23 +/- 1 degrees C, 75 +/- 5% relative humidity, and a photoperiod of 16:8 (L:D) h. Results showed that total development time of immature females was shorter on Fuji than on the other varieties, and this was because of its shorter egg duration. Immature survival of P. ulmi was 74.51-78.00% among four apple varieties, and no significant differences were found. The total fecundity per female was significantly higher on Golden Delicious (34.12 eggs per female) than that on Fuji (27.15 eggs per female), Starkrimson Delicious (25.15 eggs per female), and Granny Smith (20.62 eggs per female). Based on the intrinsic rate of population increase, Fuji and Golden Delicious were more suitable than Starkrimson Delicious and Granny Smith.