Tropimenelytron robustum Gusarov

Gusarov, Vladimir I., 2002, A revision of Nearctic species of the genus Tropimenelytron Pace, 1983 (Coleoptera: Staphylinidae: Aleocharinae), a new genus for North America, Zootaxa 114, pp. 1-24 : 14-17

2. Tropimenelytron robustum Gusarov , sp. n. ( Figs. 45­54 )

Sipalia columbica Fenyes (manuscript name).

Type material. Holotype:, UNITED STATES: Oregon: Clackamas Co.: 1.5 mi. S jct. US 26 & Ore35, 3500’, litter, mixed conifer forest (A. Newton, M. Thayer), 11.vii.1975 ( FMNH).

Paratypes: CANADA: British Columbia:, 25 mi. E Hope (Campbell & Smetana), 21.vi.1968;, Mt. Garibaldi, 14 km N Squamish, 4000' (Campbell & Smetana), 30.v.1968 (all ­ CNCI);, 2, Shawnigan Lake ( CASC).

Diagnosis. Tropimenelytron robustum differs from T. americanum in having mat pronotum and head, both with strong microsculpture; smaller eyes (temples 2.5­2.7 times as long as eyes) and narrower apex of median lobe of aedeagus in parameral view ( Figs. 50, 52 and 40, 42 ). Tropimenelytron robustum differs from T. californicum in having longer body and broader apex of median lobe of aedeagus in parameral view ( Figs. 50, 52 and 60, 62 ).

Description. Length 3.4­3.7 mm. Body reddish brown, elytra and legs slightly lighter.

Head surface mat, on disk with strong isodiametric microsculpture, making hard to see fine and slightly asperate punctation, distance between punctures equal to 2­3 times their diameter. Temples 2.5­2.7 times as long as eyes. Second antennal article 1.1 times as long as third, article 4 slightly transverse (ratio 1.6), articles 5­10 strongly transverse (ratio 1.8­ 2.0), last article longer than two but shorter than three preceding articles combined.

Pronotum subquadrate, 1.2 times as wide as head, width 0.53­0.57 mm, length 0.51­ 0.56 mm, length to width ratio 0.97, surface mat, microsculpture and punctation as on head. Elytra wider (0.67­0.73 mm) and as long (0.51­0.54 mm, measured from humeral angle) as pronotum (elytral length to pronotal length ratio 0.99), 1.3 times as wide as long, glossy, with isodiametric microsculpture, meshes larger than on pronotum, punctation fine and asperate, distance between punctures equal to their diameter.

Abdominal terga glossy, with fine and weak isodiametric microsculpture, with fine asperate punctation, on terga 3­5 distance between punctures equals 2­4 times their diameter, on terga 6­7 punctation finer, distance between punctures equals 3­6 times their diameter.

Male secondary sexual characters include longitudinal carina along anterior half of sutural margin of each elytron, tiny medial knob at posterior margin of tergum 3, small medial knob at apical third of tergum 4, short medial carina in front of anterior margin of tergum 7, and uneven posterior margin of tergum 8 ( Fig. 45 ). Posterior margin of male sternum 8 convex ( Fig. 46 ). Aedeagus as in Figs. 50­54 .

Female tergum 8 with slightly convex posterior margin ( Fig. 47 ), sternum 8 with straight posterior margin ( Fig. 48 ). Spermatheca as in Fig. 49 .

Distribution. Known from Western United States (Oregon) and Canada (British Columbia) ( Fig. 65 ).

Figures

FIGURE 65. Geographical distribution of Nearctic species of Tropimenelytron Pace.

FIGURES 45 ­ 48. Details of abdominal segment 8 of Tropimenelytron robustum Gusarov, sp. n. (holotype (45 ­ 46), paratype from Hope, British Columbia (47 ­ 48 )). 45 – male tergum 8; 46 – male sternum 8; 47 – female tergum 8; 48 – female sternum 8. Scale bar 0.5 mm.

FIGURES 49 ­ 54. Genitalia of Tropimenelytron robustum Gusarov, sp. n. (paratype from Hope, British Columbia (49) and holotype (50 ­ 54 )). 49 – spermatheca; 50 – median lobe of aedeagus, parameral view; 51 – median lobe of aedeagus, lateral view; 52 – apex of median lobe, parameral view; 53 – apex of median lobe, lateral view; 54 – apical lobe of left paramere, side facing median lobe. Scale bar 0.1 mm (49, 52 ­ 54), 0.2 mm (50 ­ 51).

FIGURES 39 ­ 44. Genitalia of Tropimenelytron americanum Gusarov, sp. n. (paratypes from Rockville (39) and Morgan Monroe State Park, Indiana (40 ­ 44 )). 39 – spermatheca; 40 – median lobe of aedeagus, parameral view; 41 – median lobe of aedeagus, lateral view; 42 – apex of median lobe, parameral view; 43 – apex of median lobe, lateral view; 44 – apical lobe of left paramere, side facing median lobe. Scale bar 0.1 mm (39, 42 ­ 44), 0.2 mm (40 ­ 41).

FIGURES 59 ­ 64. Genitalia of Tropimenelytron californicum Gusarov, sp. n. (paratypes from Mineral, California). 59 – spermatheca; 60 – median lobe of aedeagus, parameral view; 61 – median lobe of aedeagus, lateral view; 62 – apex of median lobe, parameral view; 63 – apex of median lobe, lateral view; 64 – apical lobe of left paramere, side facing median lobe. Scale bar 0.1 mm (59, 62 ­ 64), 0.2 mm (60 ­ 61).