This genus has a black connexivum with orange-red spots, and rather reddish-brown wings. H. apterus is normally micropterous, the wings not reaching beyond the 3rd or 4th abdominal segment. It is best separated from the smaller H. mirmicoides by the longer antennae (≥ length of thorax + abdomen), shorter wings and longer hairs on the hind tibiae (almost twice the width of the tibia itself).
Unlike other UK nabids, this is a tree-dwelling bug, found on decidous species and less frequently on conifers, where it feeds on mites, aphids and other small insects. It is common in much of England and Wales, becoming scarcer further north.
Adults lay eggs in late summer which hatch the following spring; larvae may be found May-August. The new adult generation is complete from July onwards.