Carrying and transmission of Eremothecium coryli (Peglion) Kurtzman as a causal pathogen of yeast-spot disease in soybeans by Riptortus clavatus (Thunberg), Nezara antennata Scott, Piezodorus hybneri (Gmelin) and Dolycoris baccarum (Linnaeus)

Abstract

Eremothecium coryli has been identified as the causative agent of yeast-spot disease in soybeans. To determine which true bug species might be vectors for yeast-spot disease in Japan, Riptortus clavatus, Nezara antennata, Piezodorus hybneri and Dolycoris baccarum were collected from commercially grown soybean plants in Kyoto and Hiroshima Prefectures, in July to September 2006. The carrying rates of E. coryli were 77.7, 35.7, 20.4 and 43.8% on R. clavatus, N. antennata, P. hybneri and D. baccarum adults, respectively. The carrying rate of E. coryli was 11.5% among R. clavatus nymphs. But E. coryli was not isolated from N. antennata and D. baccarum nymphs. The transmission rates of E. coryli to immature soybean seeds were 81.6, 50.0, 16.7 and 40.0% by R. clavatus, N. antennata, P. hybneri and D. baccarum adults, respectively. The results suggested that these 4 species are capable of carrying and transmitting E. coryli that cause yeast-spot disease in soybeans.