Ischnocnemis brevis Eya, 2024

Ischnocnemis brevis Eya , new species

( Fig. 409–427 View Figures 409–427 )

Description. Male: Length 9–10 mm. Form small, cylindrical, stout, parallel-sided; integument black, pronotum black with metallic bluish to aeneous cast, elytra black to dark metallic blue, abdomen black to dark reddish brown. Head small; vertex, finely, confluently punctate; front short, vertical, finely confluently punctate; postclypeus with upper margin glabrous, lower half finely, contiguously punctate; antennal tubercles prominent with apices angulate, integument deeply, contiguously punctate; genae narrow with lower half triangular, glabrous, finely punctate beneath; pubescence on vertex, margins of postclypeus, antennal tubercles, and genae obscure, short and erect; labrum densely, minutely punctate, pubescence moderately dense and suberect; antennae slender, exceeding elytral apices by three antennomers; scape conical densely, deeply, contiguously punctate, pubescence obscure, short, erect; antennomeres III–VI cylindrical with apices enlarged, integument finely, densely punctate, obscurely pubescent with short, depressed setae, ventral surface and apices with few suberect setae; remaining antennomeres opaque, densely, minutely punctate and densely covered with minute, appressed setae, apices with short, depressed setae; antennomeres from IV vaguely carinate on inner and outer surface; antennomere III longer than I; IV slightly shorter than III, longer than I; V longer than IV, subequal to III; VI, VII, VIII, and IX subequal to V; X slightly shorter than IX, subequal to IV; XI longest, apices non-appendiculate. Pronotum as long as wide (L/W: 0.88), cylindrical, sides vaguely rounded; apex narrowly collared and very narrowly constricted behind, base with sides constricted or impressed and margin expanded over humeri; disc shallowly convex, dorsal callus absent, disc finely, deeply, subcontiguously punctate, basal half to three quarters with longitudinally elongate, glabrous area in middle, pubescence obscure, short, golden, erect; proepisternal area more densely, contiguously punctate than disc, pubescence obscure, short, appressed towards dorsum with few erect setae near base; prosternum slightly concave, apical half vaguely impressed, transversely plicate, basal half finely punctate, on each side above coxae with vaguely impressed, transverse, irregularly striate-punctate, subrectangular area, pubescence obscure, moderately dense, golden erect; mesosternum glabrous with round depression in middle, sides finely, densely punctate, pubescence obscure, short, depressed; mesosternal intercoxal process as wide as coxal cavity, declivous anteriorly; mesepisterna and mesepimera rugulose, finely, densely punctate, obscurely clothed with appressed, pale pubescence; metasternum coarsely, discretely punctate with glabrous area along midline, pubescence obscure, golden, depressed; metepisterna opaque, minutely, densely punctate clothed with appressed, pale pubescence. Scutellum triangular, sparsely punctate. Elytra 2.5 times as long as broad; each elytron with a narrow raised, glabrous subsutural costae extending from base to about apical fifth, and a vaguely visible submarginal costa starting behind humerus attaining about apical third; punctures adjacent to suture fine, discrete near base, towards apices finer, denser and subcontiguous, integument between costae more coarsely, densely, punctate, between epipleural margin and submarginal costa contiguously punctate; pubescence obscure, short, suberect; apices rounded, vaguely sinuate, exterior angle obtuse, unarmed. Legs slen- der; femora finely, densely punctate, clothed with short, depressed setae; pro- and mesofemora slightly clavate; metafemora linear, slightly arcuate near base, shorter than body and attaining apex of fourth abdominal sternite; tibiae finely, densely, subcontiguously punctate, clothed with short, depressed setae; protibiae with inner surface densely clothed with short, depressed, pale pubescence; metatarsomere I subequal or slightly longer than tarsomeres II and III combined. Abdomen very sparsely, finely, punctate in middle with short, depressed, pale setae, sides minutely, densely punctate clothed with pale, appressed pubescence; apex of last sternite narrowly truncate, and vaguely emarginate at middle.

Female: Length 9–11 mm. Form slightly stouter than males; integument similar in coloration to males, occasionally with pronotum reddish with apical and basal margins and prosternum black. Prosternum transversely plicate punctate throughout, transverse subrectangular area above coxae absent. Antennae exceeding elytral apices by an antennomere, antennomeres from V vaguely carinate on inner and outer surface. Abdomen with apex of last sternite broadly truncate, and vaguely emarginate at middle.

Etymology. This species is named after its small size, Latin for “short or small” (i.e., brevis ).

Type materials. Holotype, male ( EMEC 1742826 About EMEC ), and allotype, female ( EMEC 1742828 About EMEC ) both from MEXICO: Michoacán: 14 mi NW Zitácuaro, 24 Aug. 1959, L.A. Stange, A.S. Menke both deposited in EMEC. Thirty-four paratypes, all from MEXICO: Michoacán: HWY 15, 5 mi S Tuxpan, 7 Aug. 1965, G.H. Nelson, and family (1 male, EMEC); Tuxpan km 186, 7600 ft., 5 Oct. 1941, DeLong, Good, Caldwell and Plummer (1 male, EMEC); Tuxpan , km 168, 7600 ft., 5 Oct. 1941, DeLong, Good, Caldwell and Plummer (1 female, EMEC). Guerrero: 12 km S Ixcateopan, 1530 m, 13 Sept. 1982, J.A. Powell, J.A. Chemsak (1 male, 2 females, EMEC); Teloloapan, 23 Aug. 1957, D. Douglas (1 female, EMEC);10.5 km N Iguala, 4000′, 19–21 Sept. 1989, E. Giesbert (1 female, FSCA); 11 km W Xochipala, 17 Sept. 1989, E. Giesbert (3 males, 1 female, FSCA); 22 km E Chichihualco, 5200′, 22 Sept. 1989, E. Giesbert (9 males, 7 females, FSCA); 22 km E Chichihualco, 22 Sept. 1989, J.E. Wappes (4 males, 2 females, FSCA).

Discussion. This is another Ischnocnemis species that closely resemble I. caerulescens Bates and I. sexualis Bates. It differs from other Ischnocnemis without ivory vittae by the smaller, stouter form, base of the pronotum with sides that are constricted, and margins expanded over the humeri ( Fig. 420–422 View Figures 409–427 ), and elytral apices that are rounded, vaguely sinuate with exterior angles obtuse and unarmed ( Fig. 424 View Figures 409–427 ). The elytra are shorter, 2.5 times as long as wide in this species, while for I. caerulescens and I. sexualis the elytra are more elongate, 2.8–2.9 times as long as wide, with apices truncate. This species closely resembles I. sexualis with opaque densely contiguously punctate pronotal disc, but the elytron lacks the faint costa usually visible between the raised subsutural and vague submarginal glabrous costae found in the later species. There are some color variations in this species as found in I. caerulescens and I. sexualis . The single male from Ixcateopan, Guerrero, approximately 272 km south of Zitácuaro, Michoacán, is black with abdomen, elytra, and parts of sternum testaceous to reddish brown ( Fig. 413–414 View Figures 409–427 ). The females from Ixcateopan and Teloloapan have dark metallic blue elytra, and reddish pronotum with apical and basal margins and sternum black ( Fig. 415–416 View Figures 409–427 ). This species ranges from Tuxpan, Michoacán south to Chichihualco, Guerrero based on the materials examined.