Microbiological examination of soybean pods artificially inoculated in the greenhouse confirmed that Nematospora coryli Peglion causes yeast-spot disease in soybeans. The disease normally occurred only in association with feeding by certain species of pentatomids and with mechanical inoculation. Since the organism was not transmitted incidentally through wounds that simulated insect punctures, an intimate association between insect and micro-organism was implied. Cage tests showed that Thyanta custator (F.); the green stink bug, Acrosternum hilare (Say); the brown stink bug, Euschistus serous (Say); the dusky stink bug, E. tristigmus (Say); the one-spot stink bug, E. variolarius (Palisot de Beauvois); and E. euschi-stoides (Vollenhoven) were capable of transmitting the organism which causes yeast-spot disease in soybeans.