Effect of four apple varieties on the biology and demography of the red mite

Abstract

In this study, the impact of four apple varieties on the development et reproduction of the European red mite Panonychus ulmi (Koch, 1836) (Prostigmata: Tetranychidae) was studied. The age-stage two-sex life tables of P. ulmi on Golden Delicious, Red Shief, Jeromine et the Gala varieties were constructed under experimental conditions with temperature of 25 ± 1 °C, relative humidity of 65 ± 5% et photoperiod of 16:8 (L:D). Panonychus ulmi developed better on Golden Delicious et Red Shief than the other two varieties, as indicated by high fertility (38.5 et 35.1 eggs/female) et intrinsic rates of increase (rm) of 0.1643 et 0.1521 day-1 respectively. The low values of (rm) were obtained on Gala and Jeromine (0.1263 et 0.1319 d-1). The results showed that the total development time of immature females was shorter on Golden Delicious (11.2 days). Immatures survival was significantly higher on Golden Delicious, Jeromine and Red Shief (79.1, 76.5 and 72.3 %, respectively) and significantly lower on the Gala variety (64.5%). In the absence of careful management, Panonychus ulmi swarm quickly on Golden Delicious and Red Shief varieties, which are appropriate among the four varieties tested.

Keywords

• Panonychus ulmi
• life table
• apple
• fecundity
• Development
• Reproduction