Eleusis nigerrima ( FAUVEL, 1864 )

Irmler, Ulrich, 2017, The Neotropical species of the genus Eleusis LAPORTE, 1835 with description of the new genus Eleusima (Coleoptera: Staphylinidae: Osoriinae), Beiträge Zur Entomologie = Contributions to Entomology 67 (2), pp. 275-318 : 286-287

Eleusis nigerrima ( FAUVEL, 1864)

Figs 4 A-C, 28G, 32, 35b

Isomalus nigerrimus FAUVEL, 1864: 37

Isomalus dubius SHARP, 1876: 411 new synonymy

Eleusis infima SHARP, 1887: 731 new synonymy

Eleusis marginicollis BERNHAUER, 1921: 65 new synonymy

Eleusis armuellensis BIERIG, 1931: 426 new synonymy

Type material examined: male, Holotype: Brazil: Novo Friburgo ( IRSNB). Two syntypes of E. dubius : Brazil: Amazonas, male, female ( BMNH). The male syntype was selected as lectotype for E. dubius ; male lectotype of E. infima , Nicaragua: Chontales, leg. Janson ( BMNH); syntype female with same data as lectotype ( BMNH). The two syntypes are deposited in the BMNH; the male syntype was selected as lectotype; male holotype of E. marginicollis: Columbia : Bang-Haas ( FMNH); male holotype of E. armuellensis : Panama: Puerto Armuelles, 8.1930, leg. Bierig (No. Z-13812); females paratype and cotype: with same data as holotype (Z-13812) ( FMNH).

Additional material examined: country not defined, pampas, 1 male, 1 female ( IRSNB) : Costa Rica: Heredia, La Selva , Bio. Sta. 3 km S Puerto Viejo (10°26'N, 84°01'W), female, 6.1991, leg. Hespenheide ( KNHM) ; Panama: Canal Zone , Barro Colorado Is., under bark fermenting, 3 males, 5 females, 16.2.1976, leg. A. Newton ( FMNH) ; Barro Colorado Island (9°11'N, 79°51'W), rotting Gustavia superba fruits, female, 26.7.2000, leg. S. Chatzimanolis #PAN1C0091 ( KNHM) ; Canal zone, 4 mi. NW Gamboa, under bark, 7 females, 23.2.1975, leg. J.F. Lawrence ( FMNH) ; Panama, Old Plantation Trail, km 3.5, Parque Soberania , 150 m elev., male, 4.7.1995, leg. A. Gillogly ( KNHM) ; same location, but 4 km Parque Soberania , 175 m elev., 3 females, 1.- 2.7.1995, leg. A. Gillogly ( KNHM) ; Panama Prov., Canal Area, PN Soberania, 2.5 km N of Summit, Plantation Rd. km 0-1, beating, male, 31.8.2010, leg. Sekerka ( BMNH) ; Colombia : without more data 2 males, 1 female (coll. Kraatz) ( SDEI) ; Villa del Cauca, PNN Farallones de Cali, Anchicaya (76°46'W, 3°26'N), 900 m elevation, Malaise trap, female, 10.- 25.10.2000, leg. S. Sarria #M1108 ( KNHM) ; Amazonas, PNN Amacayacu Matamata (70°15'W, 3°41'N), 150 m elevation, Malaise trap, male, 11.- 25.9.2000, leg. A. Parente #M846 ( KNHM) ; French Guiana: Réserve Trésor (4°36.37'N, 52°16.44'W), ca. 225 m elev., window trap, female, 12.2009, leg. S. Brule ( BMNH) ; Ecuador: Sucumbios, Sacha Lodge (76°27.35'W, 0°28.14'S), under bark, 2 males, 24.3.1999, leg. R. Brooks #ECU1B99031 ( KNHM, UIC) ; Pastaza, Llandia , 17 km N Puyo, remnant rainforest, female, 16.7.1994, leg. F. Génier ( KNHM) ; Chimborasso , 1000 ft. elev., female, 8.1896, leg. Rosenberg ( IRSNB) ; Peru: Tambopata Prov., Madre de Dios Dpto. , 15 km NE Puerto Maldonada, Reserva Cuzco Amazónico (69°03'W, 12°33'S), 200 m elevation, under bark, under bark with fermenting sap, camp, 31 males, 46 females, 30.6., 1.7., 3.7., 9.7.1989, leg. J.S. Ashe, R.A. Leschen, #348, #356, #377, #449, #481A, #485 (67 KNHM, 14 UIC) ; same location, but cornestone polypore, 2 males, 18.7.1989, leg. R. Leschen #571 ( KNHM) ; same location, swamp trail, flight intercept trap, female, 17.7.1989, leg. R. Leschen #485 ( KNHM) ; Manabi, Yuyapichis, Panguana Biol. Station , female, 8.11.- 6.12.1984, leg. M. Verhaagh ( UIC) ; Pasco Dept., Villa Rica Rd. (10°47.6'S, 75°18.54'W), flight intercept trap, male, 15.10.1999, leg. R. Brooks, D. Brzoska # PERU 1B99030C ( KNHM) ; Loreto, 1.5 km N Teniente Lopez (2°35.66'S, 76°06.92'W), 210-240 m elev., flight intercept trap, male, 22.7.1993, leg. R. Leschen #164 ( KNHM) ; Bolivia: Cochabamba, 16.7 km W Villa Tunari, Parque Machias (65°24.42'W, 16°58.20'S), 300 m elev., lowland rainforest, 1 male, 3 females, 12.2.1999, leg. R. Anderson, #BOL1A99037 ( KNHM) ; Cochabamba, Cristalmayu , 1 male, 1 female, 28.8.1949, leg. L. Peña ( NMW) ; Yuracaris , male, ( IRSNB) ; Brazil: Blumenau , female, without more data ( IRSNB) ; Santa Catarina , 1 male, 1 female coll. PE. Klimsch ( NMW) ; Pebas , without more data male ( BMNH) ; Paraguay: Cazaapa Hermosa, prop. Sosa family San Rafael Reserve (26°19.15'S, 55°44.55'W), 90 m elev., fermenting tree wound, 3 males, 4 females, 4.12., 5.12.2000, leg. Z.H. Falin #PAR1F00104 (5 KNHM, 2 UIC) .

Diagnosis: The species is extremely variable in the male sex regarding shape of head and pronotum. It resembles E. interrupta and E. humilis in colouration and can be separated from these species only by dissection of the aedeagus. On average, E. nigerrima is slightly larger than E. humilis , even in the female sex. The shape of the aedeagus resembles that of E. humilis with an acute apex. However, the prominence of the central lobe of the aedeagus is larger and the apical transparent lobe of the paramere is wider and without the long thick apical seta. The fine setae at the apical part of the transparent lobe are longer than in E. humilis . The range of the head size in males is extremely variable, which certainly leads to the misinterpretation of Sharp, Bierig, and Bernhauer. I could find no differences in the female sex and no specific difference between the aedeagi of the described species. Moreover, various sizes in male head and pronotum were found in single populations with large number of specimens such as in Panama and in Peru. Therefore, I decided to synonymise the species.

Description: Length: 3.1 – 3.5 mm. Colouration: head and pronotum black; abdomen dark brown; elytra with dark spot at scutellum and dark stripe at posterior margin; lighter colouration of central elytra varying from light brown to dark brown; legs and antennae light brown; apical antennomeres darker brown.

Head: 0.47 mm long, 0.48 mm wide; eyes not prominent; small; on average, EL:HL ratio = 0.21; temples as long as eyes; behind temples continuously narrowed to neck; preocular sides shortly parallel to base of antennae; anterior margin of clypeus sinuate; central prominent part wide and smoothly rounded; supraocular groove as long as eyes and temples; punctation moderately deep and irregularly sparse; interstices between punctures twice to four times as wide as diameter of punctures; microsculpture moderately deep; on clypeus with transverse striae; on vertex with longitudinal striae; surface moderately shiny.

Antennae as long as head and half of pronotum combined; first antennomere thicker than two following antennomeres; second and third antennomeres half as long as first antennomere; slightly longer than apical width; fourth to sixth antennomere quadrate; following antennomeres wider than long; tenth antennomere 1.5 times as wide as long; fourth to eleventh antennomere pubescent; all antennomeres with short apical setae.

Pronotum: 0.36 mm long, 0.45 mm wide; widest close to anterior angles; anterior angles shortly rounded; evenly narrowed to posterior angels; at posterior margin 0.6 times as wide as at anterior angles; punctation similarly deep and sparse as on head; close to anterior angles with three large setiferous punctures; lateral margin interrupted at beginning of posterior half; interruption marked by deep setiferous puncture; microsculpture similarly deep as on head and with longitudinal striae; at anterior angles curved; surface moderately shiny.

Elytra: 0.50 mm long, 0.52 mm wide; widest close to posterior angles; continuously narrowed to rounded humeral angles; punctation deeper and denser than on pronotum and head; interstices between punctures as wide as to twice as wide as diameter of punctures; microsculpture finer than on pronotum; longitudinally striate; surface shinier than on pronotum.

Abdomen sparsely punctate; microsculpture with weak transverse striae.

Aedeagus approximately parallel in ventral aspect; in lateral aspect, shortly narrowed to acute apex; in medial position of apical part with triangular prominence; along midline with row of sensillae; denser at triangular prominence; paramere shorter than central lobe; with wide transparent apical lobe; apical margin of transparent lobe with fringe of numerous setae and minute sensillae; some more sensillae along basal scape.

Figures

Fig. 2–6: Eleusis interrupta (2), E.humilis (3), E. nigerrima (4), E. boliviana (5), E. andina (6); aedeagus in lateral (A) and ventral (B)