Improved Strategies for Branching on General Disjunctions Author Liberti, Gianfranco text Zootaxa 2009 2009-12-22 2318 339 385 http://dx.doi.org/10.1184/r1/6705962.v1 journal article 10.1184/r1/6705962.v1 1175-5326 5307249 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