Comparative Life Tables of the Potato Tuberworm, Phthorimaea operculella, on Leaves and Tubers of Different Potato Cultivars

The potato tuberworm, Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae), is a serious pest of the potato, Solanum tuberosum L. (Solanales: Solanaceae), in both fields and stores in tropical and subtropical regions. In the present study, the susceptibility of different potato cultivars to P. operculella was evaluated by measuring life table parameters. Tests were undertaken with leaves and tubers of 10 potato cultivars in the laboratory: Agria, Agata, Almera, Arinda, Baneba, Fiana, Marfona, Ramus, Satina, and Volvox. All parameters showed significant differences among tested cultivars. The longest mean generation times were observed on Marfona and Satina cultivars in the experiments on potato leaves and tubers, respectively. The lowest reproductive rate was observed on leaves and tubers of Marfona cultivar. Correspondingly, the lowest values of intrinsic rate of increase and the lowest finite rate of increase were also obtained on Marfona cultivar in tests on potato leaves and tubers. The highest intrinsic rate of incrase values were observed on Arinda and Baneba in the tests on leaves and tubers, respectively. The intrinsic rates of increase were significantly higher on potato leaves than on potato tubers. The lower performance of P. operculella on Marfona cultivar indicated that this cultivar is relatively less susceptible this pest and could be used in integrated pest management programs of P. operculella.