Eriogaster arbusculae is a moth in the family Lasiocampidae. It is found in parts of the Alps and mountainous areas of Fennoscandia. The wingspan is 31–35 mm for males and 36–43 mm for females. The ground colour of the forewings is dark reddish-brown to greyish-brown. The hindwings are lighter. There is one generation per year with adults on wing from April to July.