PATTERNS AMONG HOST PLANTS OF POTATO LEAFHOPPER, EMPOASCA-FABAE (HOMOPTERA, CICADELLIDAE)

Ecological characteristics of potato leafhopper, Empoasca fabae (Harri s), including polyphagy, suggest that non-economic plant species in th e landscape may be important to its population ecology. The objectives of this study were to compile a host list, to ascertain taxonomic and ecological patterns within the list, and to determine host utilizatio n in non-crop habitats. The host plant list included 220 species in 10 0 genera and 26 families. Fabaceae represented 47% of the genera and 6 2% of the species. Yet, the list includes a diversity of taxonomic gro ups within the class Magnoliopsida, representing highly divergent chem istry and morphological types. Ecological classifications, based on su ch characteristics as habitat, growth form, and origin, were similarly diverse. Thus, the diversity of plant species suitable for reproducti on suggests that non-crop habitats may be a significant source of pota to leafhopper populations after spring migration into northern states. Also, the ability of leafhopper adults to utilize additional species (e.g., grasses, pines) as refugia provides a secondary role to non-cro p habitats. Yet, our limited data suggest that utilization of non-crop habitats for reproduction is restricted to a relatively few naturaliz ed hosts (e.g., deciduous trees). Host finding behavior, operating at a landscape or habitat level, as well as abiotic and biotic factors wi thin habitats, may limit host utilization in non-crop habitats.