Psammostiba kenaii Gusarov

Gusarov, Vladimir I., 2003, A revision of Nearctic species of the genera Adota Casey, 1910 and Psammostiba Yosii & Sawada, 1976 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 185, pp. 1-35 : 28-32

2. Psammostiba kenaii Gusarov , sp. n.

( Figs. 78­87 )

Type material. Holotype:, UNITED STATES: Alaska: Haines Co.: Haines (Campbell & Smetana), 3.vii.1968 ( CNCI).

Paratypes: UNITED STATES: Alaska: Haines Co.:, 4, Haines, sifting algae on beach (Campbell & Smetana), 3.vii.1968 ( CNCI, SPSU); Kenai Peninsula Co.:, Homer, S shore of Homer spit, 59º36.33'N 151º25.71'W, sandy seashore, in seaweed (V.I.Gusarov), 22.vii.1998 ( SPSU).

Additional material. UNITED STATES: California: Mendocino Co.:, Needle Rock, on beach (D.Giuliani), 6.x.1974 (UCR); CANADA: British Columbia:, Victoria ( CASC).

Diagnosis. Psammostiba kenaii can be distinguished from P. comparabilis by smaller body, smaller aedeagus with narrower apex ( Figs. 82­83 ; 73­74) and smaller spermatheca ( Figs. 87 ; 77).

Psammostiba kenaii can be distinguished from the Palaearctic species of Psammostiba by the fine crenulation of the posterior margin of male tergum 8 ( Fig. 78 ), and by the distinct shape of aedeagus ( Figs. 82­86 ) and spermatheca ( Fig. 87 ).

Description. Length 3.0­ 3.1 mm. Body black, elytra dark brown to black, legs brown, tarsi yellowish brown.

Head surface matte, with strong and dense isodiametric microsculpture, with fine and poorly visible punctation, distance between punctures equals their diameter; in both sexes with weak medial impression. Temple length to eye length ratio 0.9­1.0. Antennal article 3 longer than article 2, articles 4­7 elongate, 8­10 elongate or subquadrate, article 11 shorter than articles 9 and 10 combined.

Pronotum slightly transverse, 1.2 times as wide as head, width 0.59­0.64 mm, length 0.47­0.53 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 (0.76­0.86 mm) and longer (0.70­0.76 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. 78 ). Posterior margin of male sternum 8 convex ( Fig. 79 ).

Aedeagus as in Figs. 82­86 .

Spermatheca as in Fig. 87 .

Distribution. Known from the Pacific coast of Alaska ( Fig. 88 ). Records from British Columbia and California are based on female specimens and need to be reconfirmed when male specimens become available.

Natural History. Psammostiba kenaii is a littoral species, inhabiting decomposing seaweed on a beach.

Figures

FIGURE 88. Geographical distribution of Nearctic species of Psammostiba. Records of P. kenaii Gusarov, sp. n. from British Columbia and California are based on female specimens only.

FIGURES 78 ­ 81. Abdominal segment 8 of Psammostiba kenaii Gusarov, sp. n. (holotype, male (78 ­ 79), and paratype, female (80 ­ 81), from Haines, Alaska). 78 – male tergum 8; 79 – male sternum 8; 80 – female tergum 8; 81 – female sternum 8. Scale bar 0.2 mm.

FIGURES 82 ­ 87. Genitalia of Psammostiba kenaii Gusarov, sp. n. (holotype, male (82 ­ 86), and paratype, female (87), from Haines, Alaska). 82 – median lobe, parameral view; 83 – apex of median lobe, parameral view; 84 – median lobe, lateral view; 85 – apex of median lobe, lateral view; 86 – apex of left paramere; 87 – spermatheca. Scale bar 0.1 mm (83, 85 ­ 86), 0.2 mm (82, 84, 87).