The yellow flowers of Bristly Ox-tongue outside the Visitor Centre are being frequented by two species of hoverfly of the same genus. One is common hereabouts, the other has not been recorded here before. Both are recognisable by the sharpness of the elongate black wing stigma. Dasysyrphus albostriatus is frequently seen and is recognisable by the white thoracic stripes that inform the name. Dasysyrphus tricinctus is noticeably darker and has a very uneven yellow stripe configuration on the abdomen.