Tropimenelytron americanum 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 : 12-13

1. Tropimenelytron americanum Gusarov , sp. n. ( Figs. 16­18, 21 , 35­44 )

Type material. Holotype:, UNITED STATES: Indiana: Monroe Co.: Morgan Monroe State Forest, leaf litter (L.E. Watrous), 18.iv.1981 ( FMNH);

Paratypes: UNITED STATES: Indiana: 2,, same data as the holotype ( FMNH, KSEM, SPSU); Parke Co.:, 4 mi. W Rockville, aerial plankton (H. Dybas), 19.viii.1977 ( FMNH);, ditto but 2.ix.1977 ( FMNH); Iowa: Jackson Co.:, Maquoketa Caves State Park, upland forest litter (S. Peck), 25.vii.1968 ( FMNH); Missouri: Buchanan Co.:, 19 km SSW St. Joseph, Bluffwoods State Forest, 39º37.37'N 94º58.02'W, 150 m (V.I. Gusarov), 12.iv.1999 ( SPSU); Wisconsin: Eau Claire Co.: 3, 2 mi. S Eau Claire, “floor u. bark, chips pine – maple wood” (W. Suter), 6.v.1976 ( FMNH, SPSU); Ohio: Hocking Co.:, Crane Hollow (L.E. Watrous), 10.v.1975 ( FMNH); Franklin Co.:, Columbus, leaf litter (P.W. Kovarik), 15.iv.1989 ( FMNH); Pennsylvania: Allegheny Co.:, near Sutersville, litter at log on hill side (W. Suter), 16.vi.1977 ( FMNH); New Jersey: Morris Co.: 2, Green Pond, Pt. Comfort, tree hole with ants (W. Suter), 15.viii.1979 ( FMNH); New York: Chataugua Co.:, 2 mi. S Westfield (L.E. Watrous), 16.vi.1979 ( FMNH); Albany Co.:, Rensselaerville, E.N.Huyck Pres., falls area, birch log (W. Suter), 8.viii.1974 ( FMNH);, ditto but ravine near Lincoln pond, litter at birch log, 18.viii.1974 ( FMNH); Connecticut: New London Co.: 2, (L.E. Watrous), 5.v.1974 ( FMNH, SPSU);, ditto but 12.v.1974 ( KSEM); CANADA: Quebec:, Gatineau Park., Old Chelsea, birch log and litter at log (W. Suter), 26.vii.1977 ( FMNH).

Diagnosis. Tropimenelytron americanum can be distinguished from the two other Nearctic species of Tropimenelytron by having glossy pronotum without or with very weak microsculpture, head with weak and partially absent microsculpture, larger eyes (temples 1.5­1.7 times as long as eyes), broader apex of median lobe of aedeagus (in parameral view) ( Figs. 40, 42 and 50, 52 , 60, 62 ).

Description. Length 2.7­3.6 mm. Head reddish brown to dark brown, pronotum brownish yellow to reddish brown, elytra yellow to brownish yellow, abdomen brownish yellow to reddish brown, segment 6 often darker with light posterior margin, legs yellow, antennae and mouthparts brownish yellow to brown.

Head surface glossy, on disk with weak or partially absent isodiametric microsculpture, punctation fine, distance between punctures equals 2­5 times their diameter. Temples 1.5­1.7 times as long as eyes. Second antennal article 1.4 times as long as third, article 4 slightly transverse (ratio 1.3), articles 5­10 transverse (ratio 1.5­1.7), last article longer than two but shorter than three preceding articles combined ( Fig. 14 ).

Pronotum subquadrate, 1.2 times as wide as head, width 0.47­0.60 mm, length 0.43­ 0.57 mm, length to width ratio 0.93, surface glossy, with completely lacking or very weak isodiametric microsculpture; punctation as on head, distance between punctures equals 2­5 times their diameter. Elytra much wider (0.56­0.74 mm) and slightly longer (0.44­0.66 mm, measured from humeral angle) than pronotum (pronotal length to elytral length ratio 0.96), 1.3 times as wide as long, glossy, with completely lacking or very weak isodiametric microsculpture and punctation as on pronotum.

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 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. Some (smaller) males may lack these features altogether and externally look like females. Male tergum 8 with uneven and slightly convex posterior margin ( Fig. 35 ). Posterior margin of male sternum 8 convex ( Fig. 36 ). Aedeagus as in Figs. 40­44 , 16­18, 21 .

Female tergum 8 and sternum 8 with slightly convex posterior margin ( Figs. 37­38 ). Spermatheca as in Fig. 39.

Figures

FIGURES 16 ­ 21. Male genitalia of Tropimenelytron americanum Gusarov, sp. n. (paratypes from Rensselaerville, New York (16 ­ 18) and Morgan Monroe State Park, Indiana (21 )) and T. tuberiventre (Eppelsheim) (Polikesh, Azerbaijan (19 ­ 20 )). 16 – everted internal sac of aedeagus, lateral view; 17 – medial lamellae, parameral view; 18 – copulatory piece, parameral view; 19 – apex of everted internal sac, lateral view; 20 – apex of everted internal sac, parameral view; 21 – internal sac retracted in median lobe, parameral view. CP ­ copulatory piece; ML ­ medial lamellae. Scale bar 0.1 mm.

FIGURES 35 ­ 38. Details of abdominal segment 8 of Tropimenelytron americanum Gusarov, sp. n. (paratypes from Morgan Monroe State Park (35 ­ 36) and Rockville, Indiana (37 ­ 38 )). 35 – male tergum 8; 36 – male sternum 8; 37 – female tergum 8; 38 – female sternum 8. Scale bar 0.5 mm.

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 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 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).

FIGURES 12 ­ 15. Details of Tropimenelytron americanum Gusarov, sp. n. (paratype from Eau Claire, Wisconsin). 12 – pronotum; 13 – mesometathorax, ventral view; 14 – right antenna; 15 – right metatarsus. Scale bar 0.4 mm (12 ­ 14), 0.2 mm (15).