1 Males: spatuliform apex of median lobe (in parameral view) smaller, 1.1 times as wide as median lobe measured subapically at its narrowest point (Figs. 22 –23, 26– 27). Body length 3.0– 3.9 mm, pronotal length 0.49–0.57 mm. Distributed along the Pacific coast of North America (California) (Fig. 66). Also known from Europe, Chile, New Zealand and Inaccessible Island of the Tristan da Cunha archipelago.......................................................................................................... 1. H. algophila (Fenyes)
– Males: spatuliform apex of median lobe (in parameral view) larger, 1.4–1.6 times as wide as median lobe measured subapically at its narrowest point (Figs. 41–44). Body length 2.9–3.2 mm, pronotal length 0.43–0.51 mm. Distributed along the Atlantic coast of North America (Virginia, New York) (Fig. 66). Also known from Europe and Chile......................................................................................... 2. H. flavipes Thomson