POTATO LEAFHOPPER (HOMOPTERA, CICADELLIDAE) MOVEMENT, OVIPOSITION, AND FEEDING RESPONSE PATTERNS IN RELATION TO HOST AND NONHOST VEGETATION

The influence of minor and nonhost vegetation on bean, Phaseolus vulgarts L., host plant acceptance by the potato leafhopper, Empoasca fabae (Harris), was studied, with emphasis on the influence of tomato, Lycopersicon esculentum Mill. Cage environments in the laboratory and greenhouse were used to observe leafhopper movement and arrestment and to evaluate performance criteria, including feeding and oviposition. The presence of tomato vegetation suppressed total excreta production (an index of feeding) by 43%. Reduced excreta production was a result of considerable residence time on tomato. In oviposition choice tests, only 28% of the eggs were laid on bean in proximity to tomato. No-choice tests gave similarly significant results. Cabbage also reduced oviposition when in proximity to bean. In choice tests, only 32% of the eggs were laid on bean in proximity to cabbage. There were no differences in the average length of time on bean during each arrestment bout in treatment cages containing a combination of bean and companion plant leaves versus the control containing only bean leaves. When evaluating leafhopper movement frequency from surface to surface (i.e., the two leaves and cage surfaces), no significant difference was found when comparing the bean control with the bean and tomato treatment. It is suggested that tomato plants can directly reduce the interaction between bean plants and leafhopper through an extensive "nonproductive" residency time on tomato plants. The importance of evaluating insect and plant interactions based on multiple criteria is discussed. © 1990 Entomological Society of America.