A field study of potato leafhopper (Homoptera: Cicadellidae) abundance and damage on alfalfa cultivars and perennial glandular-haired Medicago strains

Four perennial, glandular-haired Medicago spp. strains and four alfalfa (M. sativa L.) cultivars were sampled for potato leafhopper (PLH), Empoasca fabae (Harris), abundance and damage in replicated field plots during 1986, 1987, and 1988. Sweep samples were used to determine leafhopper abundance, and plant discoloration was rated visually to estimate damage. PLH were less abundant on the glandular-haired M. glandulosa and M. glutinosa than on the M. sativa cultivars in all three years. Less damage was observed on M. glandulosa than on any other entry in 1986 and 1988. These results suggest that nonglandular PLH resistant alfalfa cultivars would benefit from the incorporation of PLH resistance from glandular-haired Medicago species.