Comparative Biology and Life Tables of 'Candidatus Liberibacter Solanacearum'-Infected and -Free Bactericera Cockerelli (Hemiptera: Triozidae) on Potato and Silverleaf Nightshade

摘要

The potato psyllid, Bactericera cockerelli (Sulc), vectors the pathogen "Candidatus Liberibacter solanacearum" (Lso), causal agent of zebra chip disease of potato. Several cultivated and wild plants are reported to serve as alternate hosts for B. cockerelli and Lso, including silverleaf nightshade (SLN), a wild solanaceous woody perennial weed that occurs throughout Texas. Experiments were conducted in the laboratory to compare performance of Lso-infected and Lso-free B. cockerelli on SLN and potato. Results showed that host plants and Lso-infection significantly influenced the performance of B. cockerelli. Egg incubation and nymphal development of Lso-infected and Lso-free immatures were prolonged on SLN compared with potato indicating a host effect. Generally, Lso-infected B. cockerelli immatures developed faster on both SLN and potato, although significantly more Lso-free nymphs survived than nymphs that harbored the pathogen. Lso-free adults also lived longer and laid more eggs on potato than SLN. According to life table estimates, intrinsic and finite rates of increase of Lso-infected B. cockerelli were not significantly different from Lso-free individuals on potato and SLN. Analysis of the two factors revealed significant interaction effects between host and Lso and that development and reproduction of B. cockerelli is a function of both Lso-infection and host on which it fed. Results of this study suggests that Lso does not have a negative effect in the overall performance of B. cockerelli on both hosts and also demonstrated SLN to be an important alternative host that supports survival of Lso-infected and Lso-free B. cockerelli populations.