During field research conducted in the spring 2020 near Wyszków (Masovian Lowland), 31 species of true bugs have been collected. In the analysed material, six specimens of Criocoris quadrimaluculatus, species new to the Polish fauna were present. This species was collected on two sites in similar environments strongly connected with the river Bug banks. As known distribution of C. quadrimaculatus in Europe is limited to the north-eastern part of the continent, we hypothesize the river Bug valley as a potential migration route from the eastern part of the species range. Moreover, the list of new records of true bugs from the environs of Wyszków in 2020, and a summary of literature data on true bugs known from the entire river Bug valley, is presented.