Psammostiba comparabilis
Creators: name: Gusarov, Vladimir I.
Publisher: name: Zenodo
Year: 2003
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Psammostiba
Psammostiba comparabilis

description: 1. Psammostiba comparabilis (Mäklin in Mannerheim, 1853), comb. nov.
(Figs. 64, 66, 68­77)
Homalota comparabilis Mäklin in Mannerheim, 1853: 181.
Atheta (Metaxya) comparabilis: Fenyes, 1920: 199 (as valid species).
Atheta (Metaxya) comparabilis: Bernhauer & Scheerpeltz, 1926: 613 (as valid species). Atheta (Brundinia) comparabilis: Moore & Legner, 1975: 357 (as valid species). Philhygra comparabilis: Seevers, 1978: 266 (as valid species).
Adota comparabilis: Lohse & Smetana, 1985: 294 (as valid species).
Type material. Lectotype of Homalota comparabilis (designated by Lohse and Smetana (1985)), UNITED STATES: Alaska: Kodiak (MZHF).
Additional material. UNITED STATES: Alaska: Kenai Peninsula Co.: 15 specimens, Homer, S shore of Homer spit, 59º36.33'N 151º25.71'W, sandy seashore, in seaweed (V.I.Gusarov), 22.vii.1998 (AMNH, SPSU); California: Mendocino Co.: 2, Needle Rock, on beach (D.Giuliani), 6.x.1974 (UCR); CANADA: British Columbia: 2, 4, Queen Charlotte Islands, Graham Island, Toe Hill, "ex on rocks in intertidal" (J.S.Ashe), 14.vii.1988 (KSEM);, Victoria (CASC).
Diagnosis. Psammostiba comparabilis can be distinguished from P. kenaii by larger body, larger aedeagus with wider apex (Figs. 73­74; 82­83) and larger spermatheca (Figs. 77; 87).
Psammostiba comparabilis can be distinguished from the Palaearctic species of Psammostiba by the fine crenulation of the posterior margin of male tergum 8 (Fig. 69), and by the distinct shape of aedeagus (Figs. 68, 73­76) and spermatheca (Fig. 77).
Description. Length 4.0­ 4.6 mm. Body black with brown legs and light brown tarsi.
Head surface matte, with strong and dense isodiametric microsculpture, with fine punctation, distance between punctures equals their diameter; in both sexes with weak medial impression. Temple length to eye length ratio 0.9­1.1. Antennal article 3 is 1.2 times as long as article 2, articles 4­10 elongate (ratios 1.5 (4­5), 1.4 (6), 1.3 (7) and 1.1 (8­ 10)), article 11 shorter than articles 9 and 10 combined (Fig. 54).
Pronotum slightly transverse, 1.2 times as wide as head, width 0.80­0.89 mm, length 0.69­0.79 mm, width to length ratio 1.2; surface matte, with strong and dense isodiametric microsculpture; punctation finer than on head, poorly visible on matte background, distance between punctures equal to ½­1 times their diameter. Elytra much wider (1.10­1.30 mm) and longer (0.99­1.17 mm; measured from humeral angle) than pronotum (elytral length to pronotal length ratio 1.5), 1.1 times as wide as long, surface matte, with strong and dense isodiametric microsculpture; punctation as on pronotum.
Abdominal terga matte, with strong and dense isodiametric microsculpture, with fine punctation, punctation on terga 6­7 almost as dense as on terga 3­5, distance between punctures equals 1­3 times their diameter. Apical margin of tergum 7 with white palisade fringe.
Posterior margin of male tergum 8 with fine crenulation (Fig. 69). Posterior margin of male sternum 8 convex (Fig. 70).
FIGURES 69­72. Abdominal segment 8 of Psammostiba comparabilis (Mäklin) (male (69­70) and female (71­72) from Homer, Alaska). 69 – male tergum 8; 70 – male sternum 8; 71 – female tergum 8; 72 – female sternum 8. Scale bar 0.4 mm.
Natural History. Psammostiba comparabilis is a littoral species, common in decomposing seaweed on a beach.
description: Published as part of Gusarov, Vladimir I., 2003, A revision of Nearctic species of the genera Adota Casey, 1910 and Psammostiba Yosii & Sawada, 1976 (Coleoptera: Staphylinidae: Aleocharinae), pp. 1-35 in Zootaxa 185 on pages 25-28, DOI: 10.5281/zenodo.156388