A scentless plant bug feeds on velvetleaf seeds. Fungi, dominated by the genera Fusarium and Alternaria, were isolated from insect-attacked seeds at levels related to insect density on the plants. The combined effects of insect feeding and fungal infection decreased seed germination. Burial of insect-attacked seeds in soil for 24 months reduced seed survival and increased Fusarium infection. Decreases in velvetleaf seed viability and survival in soil caused by a seed-feeding insect and associated seed fungi suggests that subsequent infestations by velvetleaf can be decreased through integrated use of the two biological control agents.

Field infestations of a seed-feeding insect developed from overwintered populations reduced viability of velvetleaf seed to 17.5 and 15.5% at two locations in central Missouri, compared to 95.5 and 87.5% at insect-free sites. Insect feeding enhanced the proportion of seedborne microorganisms in seed up to 98% compared to the average fungal infection of 8% for seed not exposed to the insect. There was a strong negative correlation between fungal infection associated with insect feeding and percent velvetleaf seed viability. The insect transmits microorganisms externally just as pollen is carried by various other insect species and not by ingestion and regurgitation. The effectiveness of the insect on reducing seed viability and seed production in central Missouri is mainly limited by the time required to build up populations capable of significantly affecting early-season velvetleaf seed production.