Alteration of spermosphere ecosystems affecting oviposition by the bean seed fly and attack by soilborne fungi on germinating seeds

In laboratory studies, treating ‘Butternut’ squash (Cucurbita pepo) seeds with ascospores of Chaetomium globosum NRRL 6296 and 6297 reduced oviposition by the bean seed fly Hylemya platura (Meigen), and reduced seed rot caused by Pythium ultimum and P. aphanidermatum. Treatment of seeds with thiram or captan increased oviposition by the bean seed fly. In the field, treatment of snap bean seeds with C. globosum NRRL 6296, or a commercial seed treatment mixture containing captan, diazinon, and streptomycin sulphate, resulted in significantly less damage by bean seed fly larvae than a treatment with thiram.