Psilothrix Redtenbacher

Liberti, Gianfranco, 2009, Improved Strategies for Branching on General Disjunctions, Zootaxa 2318, pp. 339-385 : 350

Key to species of genus Psilothrix Redtenbacher

1. Male 7 th sternite (5 th visible) very deeply emarginated on posterior edge. Pronotum longer than wide. Wingless (actually brachypterous), showing elytral modifications often associated with loss of wings: lack of humeral callous, elytron narrow at base and widened in apical third (in female only). Length 4.0– 5.5 mm .............................. protensa

- Male 7 th sternite straight or only slightly emarginated on posterior edge. Pronotum wider than long. Wing may or may not be present ........................................................................................................................................................ 2

2. Pygidium (last male tergite) with a deep U-shaped notch ( Fig. 22 ). This species can be winged or brachypterous: only the brachypterous form is known from Sardinia, but it does not show the elytral modifications often associated with loss of wings (i.e. humeral callous normally developed, female elytron normally widened posteriorly). Small size: length 4.0– 4.5 mm ...................................................................................................................................... aureola

- Pygidium (last male tergite) showing a deep but small V-shaped notch ( Fig. 23 ). Winged. Larger size: length 4.8 to 6.6 mm ..................................................................................................................................................... viridicoerulea

Figures

FIGURES 20–23. 20–21. Median lobes in lateral view, scale bar: 0.25 mm. 20. Dolichosoma simile (Brullé) (Italy, Tuscany, Grosseto province, Talamone). 21. Dolichosoma lineare (Rossi) (Sardinia, Padrogiano). 22–23. Pygidium, scale bar: 0.5 mm. 22. Psilothrix aureola (Kiesenwetter, 1859) (Malta, Gozo Island). 23. Psilothrix viridicoerulea (Italy, Liguria, La Spezia province, Montemarcello).