The Effect of four apple varieties on the biology and demography of the red Mite: Two-sex table of life of Panonychus ulmi
The effect of four apple varieties on the development and reproduction of the European red spider mite Panonychus ulmi (Koch, 1836) (Prostigmata: Tetranychidae) was studied under the controlled conditions of 25 ± 1 °C, Relative Humidity of 65 ± 5 % and photoperiod of 16:8 (L:D). The age-stage two-sex life tables of P. ulmi on Golden Delicious, Red Shief, Jeromine and Gala varieties were constructed. Based on higher values of fecundities (38.5 and 35.1 eggs / female) and the intrinsic rates of increase (rm) of 0.1643 and 0.1521 day-1, Panonychus ulmi developed better on Golden Delicious and Red Shief among the varieties tested. Results show that the developmental time of female adults was shorter on Golden delicious and (11.2 days). Immature survival of P. ulmi was significantly higher on Golden delicious, Jeromine and Red Shief (79.1, 76.5 and 72.3 %,respectively), and lower on the Gala variety (64.5 %). In the light of these results, Panonychus ulmi develop and reproduce quickly on Golden Delicious and Red Shief varieties among the four varieties tested. Establishment of two-sex life tables of P. ulmi on apple varieties facilitates the rational management of this phytophagous mite according to the principles of integrated management.
Keywords: Panonychus ulmi, life table, apple, fecundity, Development, Reproduction