Suitability of Rosaceae fruit tree species for Panonychus citri (McGregor) (Acari: Tetranychidae)

The citrus red mite (CRM), Panonychus citri (McGregor) (Acari: Tetranychidae), a worldwide pest chiefly infesting Citrus plants, has spread from Southern China to Northern China. Little information is known about the population performance of CRM on the plants except for citrus trees and pear trees. In order to evaluate the extent of damage might caused by CRM to the fruit trees cultivated in Northern China, the performance of CRM on four Rosaceae species, including three main fruit tree species (pear-Pyrus pyrifolia Nakai cv. Shannongsu, apple-Malus pumila Mill. cv. Fuji, peach-Prunus persica (L.) Batsch cv. Zhongyou 4) cultivated in Shandong Province, Northern China, and one rootstock for grafting apples (crabapple-Malus micromalus Makino) was determined using the age-stage, two-sex life table at laboratory conditions (25 ± 1 °C, 75 ± 5% RH and L16: D8 h photoperiod). The results showed that CRM could complete the whole life cycle on all the four plant species. The development time of larva, protonymph and deutonymph and the survival of immature stage of CRM did not vary among the four plant species. Differences on the egg incubation period explained the total duration of the immature stage among the four plants. The total duration of the immature stage was shorter on pear and peach than on crabapple and apple, but no difference was observed between pear and peach. The mites reared on pear and peach exhibited a higher fecundity, net reproductive rate (R₀), intrinsic growth rate (r) and finite rate of increase (λ) and longer longevity of the adult females than on crabapple and apple, but no significant differences between pear and peach, crabapple and apple. The mean generation time (T) of CRM reared on crabapple was the longest, which did not differ significantly on pear, peach and apple. In summary, the cultivars of pear, peach, apple and crabapple used in this study, especially that of peach and pear were suitable for the development and reproduction of CRM. CRM might be a serious risk for the main Rosaceae fruit species in Northern China.