Seeds of Arctic plants face numerous threats prior to dispersal. The growing season varies across years in terms of degree days, and herbivory, predation, and pathogens are critical threats. In this study the results of different densities of the Arctic seed bug, Nysius groenlandicus (Heteroptera), piercing the seed coat of Silene acaulis and sucking out nutritional content were observed. In order to study the effect of Nysius groenlandicus on seed mass and germination of Silene acaulis, seeds were placed in Petri dishes with different densities of seed bugs. The herbivory affected the seed mass, leading to an average mass loss of 3.0% in fed-upon seeds compared to non-fed-upon seeds. However, the average seed mass lost seemed independent of the densities of seed bugs. A significant negative correlation between seed mass loss and number of germinations for seeds exposed to seed bugs was found. Furthermore, the germination speed of the seeds increased with increasing density of Nysius groenlandicus. The significance of this interaction is discussed, and we hypothesize that feeding might benefit the establishment of seedlings.