Berosus trilobus Chevrolat, 1863

Deler-Hernandez, Albert, Fikacek, Martin & Cala-Riquelme, Franklyn, 2013, A review of the genus Berosus Leach of Cuba (Coleoptera, Hydrophilidae), ZooKeys 273, pp. 73-106 : 92-96

Berosus trilobus Chevrolat, 1863 Figures 9 a–g1112a–b

Berosus trilobus Chevrolat, 1863: 207. - Gundlach 1891: 47 (diagnosis and distribution). - Spangler 1973: 354 (distribution). - Spangler 1981: 155 (diagnosis and distribution). - Hansen 1999: 95 (catalogue). - Peck 2005: 48 (checklist). - Epler 2010: 12.24 (notes on distribution).

Type locality.

Cuba.

Type material examined.

Holotype: female (MNHN): "Berosus / trifidus / Chv. Cuba / … [illegible] // von / G. Hemiosus / Sharp [= of the genus Hemiosus Sharp] // this must be / Chev. unique / type of trilobus / 1966 / PJS [= P. J. Spangler]".

Additional material examined.

CUBA: Sancti Spíritus:50 exs. (in alcohol) (BSC-E): Topes de Collantes, El Nueve, Río Caburny, 21°55'50"N, 80°00'59"W, 539 m a.s.l., 29.vi.2010, leg. A. Deler-Hernández. Camagüey: 19 exs. (in alcohol) (BSC-E): Sierra de Cubitas, Río El Roble, 21°32'53.23"N, 77°46'42.31"W, 55 m a.s.l., 14.iv.2012, leg. A. Deler-Hernández, 00144. Holguín: 6 exs. (in alcohol) (BSC-E): Jardín Botánico, Arroyo [stream], 20°51'46.8"N, 76°13'22.8"W, 84 m a.s.l., 07.xii.2008, leg. A. Deler-Hernández, 00074. Granma: 7 exs. (in alcohol) (BSC-E): Parque Nacional Turquino, La Platica, 20°00'33.80"N, 76°53'38.47"W, 800 m a.s.l., 29.iii.2012, leg. A. Deler-Hernández, 00143; 12 exs. (dry-mounted) (NMPC): Turquino NP, around La Platica, 20°0.7'N, 76°53.4'W, 880 m a.s.l. [MF24], 25-26.vi.2012 leg. A. Deler-Hernández and M. Fikáček. Santiago de Cuba: 6 exs. (in alcohol) (BSC-E): Campo Rico-II, Río Indio, 19°59'54.5"N, 75°32'4.6"W, 150 m a.s.l., 15.ix.2003, leg. A. Deler-Hernández and F. Cala-Riquelme, 00046; 4 exs. (in alcohol) (BSC-E): Gran Piedra, El Olimpo, Arroyo [stream], 20°00'33"N, 75°40'13"W, 820 m a.s.l., 04.viii.2005, leg. A. Deler-Hernández, 00016; 1 ex. (in alcohol) (BSC-E): II Palmas, La Cubana, Laguna temporal-II [temporal pool-II], 20°3'15.48"N, 76°8'3.12"W, 320 m a.s.l., 02.xii.2005, leg. Y. S. Megna, 00086; 30 exs. (in alcohol) (BSC-E): Palma Soriano, Arroyo [stream], 20°06'05"N, 75°58'44"W, 130 m a.s.l., 16.ii.2005, leg. K. Blanco, 00047; 5 exs. (in alcohol) (BSC-E): Guamá, La Mula, Río Turquino, 19°56'57"N, 76°45'36"W, 8 m a.s.l., 21.vi.2005, leg. Y. S. Megna, 00085; 6 exs. (in alcohol) (BSC-E): Guamá, Los Morones, Río Turquino, 19°58'33.6"N, 76°46'4.8"W, 200 m a.s.l., 18.vi.2008, leg. A. Deler-Hernández, 00006; 2 exs. (in alcohol) (BSC-E): San Luis, Dos Caminos, El Vivero, Laguna permanente [permanent pool], 20°11'2.50"N, 75°46'17.7"W, 150 m a.s.l., 01.viii.2008, leg. A. Deler-Hernández, 00028; 3 exs. (in alcohol) (BSC-E): San Luis, Dos Caminos, El Vivero, Río Guaninicú, 20°11'2.50"N, 75°46'17.7"W, 150 m a.s.l., 01.viii.2008, leg. A. Deler-Hernández, 00029; 31 exs. (dry-mounted) (NMPC): El Vivero, 1.6 km E of Dos Caminos, 20°10.8'N, 75°46.4'W, ca. 150 m a.s.l. [MF18], 20-21.vi.2012, leg. A. Deler-Hernández and M. Fikáček; 5 exs. (in alcohol) (BSC-E): Loma del Gato, Chan-Chan, Arroyo [stream], 19°58'27.4"N, 75°53'22.2"W, 353 m a.s.l., 27.vi.2009, leg. A. Deler-Hernández, 00118; 3 exs. (in alcohol) (BSC-E): La Redonda, Río Sevilla, 20°00'54.3"N, 75°45'45.6"W, 15 m a.s.l., 17.v.2009, leg. A. Deler-Hernández, 00154. Guantánamo: 36 exs. (in alcohol) (BSC-E) Imías, Yacabo Abajo, Río Yacabo Abajo, 20°06'05"N, 74°69'00"W, 5 m a.s.l., 24.x.2008, leg. A. Deler-Hernández and S. Muñiz, 00091; 20 exs. (in alcohol) (BSC-E): San Antonio del Sur, Macambo, Río Macambo, 20°03'26.9"N, 74°44'15.82"W, 4 m a.s.l., 25.x.2008, leg. A. Deler-Hernández and S. Muñiz, 00055; 16 exs. (in alcohol) (BSC-E): Baracoa-Maisí, Río Yumurí, 20°17'47.76"N, 74°17'39.5"W, 5 m a.s.l., 27.i.2010, leg. A. Deler-Hernández and R. Correa, 00152; 96 exs. (in alcohol) (BSC-E): Baracoa, Yunque, Río Duaba, 20°19'54.40"N, 74°34'9.08"W, 70 m a.s.l., 31.i.2010, leg. A. Deler-Hernández, 00171; 27 exs. (dry-mounted) (NMPC): El Yunque, 2.5-3.3 km SW of campismo popular, 20°19.4'N, 74°34.2'W, ca. 80-100 m a.s.l., 10.vi.2012 [MF02], leg. A. Deler-Hernández and M. Fikáček; 61 exs. (dry-mounted) (NMPC, KSEM): El Yunque, "La Cascada", ca. 2.1 km SW of campismo, 20°19.9'N, 74°34'W, ca. 60 m a.s.l. [MF07], 12-13.vi.2012, leg. F. Cala-Riquelme, A. Deler-Hernández and M. Fikáček; 2 exs. (dry-mounted) (NMPC): El Yunque, 3.2 km SW of campismo, right tributary of Duaba river, 20°19'N, 74°34'W, ca. 150 m a.s.l. [MF09], 13.vi.2012; leg. A. Deler-Hernández and M. Fikáček; 14 exs. (dry-mounted) (NMPC): El Yunque, in/around campismo popular, 20°20.4'N, 74°32.9'W, ca. 40 m a.s.l. [MF05], 10-13.vi.2012, leg. M. Fikáček; 20 exs. (dry-mounted) (NMPC): PN Alejandro de Humboldt, ca. 1.7 km NW of Santa María, 20°32'N, 74°43'W, ca. 50 m a.s.l. [MF13], 16.vi.2012, leg. A. Deler-Hernández and M. Fikáček; 18 exs. (in alcohol) (BSC-E): Baracoa, Jamal, 20°17'13.9"N, 74°25'33.6"W, 40 m a.s.l., 09.ii.2010, leg. R. Correa, 00169; 1 ex. (in alcohol) (BSC-E): Baracoa, Cabacú, Laguna permanente [permanent pool], 20°19'14"N, 74°28'58"W, 10 m a.s.l., 04.iii.2010, leg. R. Correa, 00170; 6 exs. (in alcohol) (BSC-E) 6 exs. (dry-mounted) (NMPC): Baracoa, Cabacú, Laguna permanente [permanent pool], 20°19'14"N, 74°28'58"W, 10 m a.s.l., 16.iii.2010, leg. R. Correa, 00164; 1 ex. (in alcohol) (BSC-E): La Marsella, Río Guaso, 20°26'22"N, 74°42'31"W, 60 m a.s.l., 26.i.2004, leg. Y. S. Megna, 00173; 3 exs. (in alcohol) (BSC-E): Baracoa, Loma de los Guineos, Arroyo [stream], 20°19'38.38"N, 74°35'35.37"W, 530 m a.s.l., 07.iv.2012; leg. A. Deler-Hernández, 00177. Without precise locality:2 exs. (dry-mounted) (NMPC): "O. Koechin / Cuba // Collectio / Dr. Jureček / H. Jurečková”; 1 ex. (dry-mounted) (MNHN): "1542 / 1798". DOMINICAN REPUBLIC: 25 exs. (dry-mounted) (KSEM, NMPC): near Hato Mayor, creek off Ruta 103, 02.xi.2000, leg. A. E. Z. Short.

Published Cuban records:Cuba: without specified locality(Gundlach, 1891). Pinar del Río: Quemado de Pineda ( Spangler 1981). Sancti Spíritus: Río Caburny near Topes de Collantes ( Spangler 1973); Arroyo Vegas Grande near Topes de Collantes ( Spangler 1973). Camagüey: Río El Manantiales ( Spangler 1981). Holguín: Arroyo Jarahueca ( Spangler 1981). Santiago de Cuba: II Frente, Sabanilla, Arroyo La Poa ( Spangler 1981); II Frente, Arroyo Jarahueca ( Spangler 1981); Contramaestre, Pozo Caliente, Río Contramaestre ( Spangler 1981); II Frente, Sabanilla, Río Mayarí ( Spangler 1981); II Frente, Río Ceiba affl. Río Mayarí ( Spangler 1981); III Frente, Río Brazo Seco ( Spangler 1981); III Frente, Matías, Río Mogote ( Spangler 1981). Guantánamo: Maisí, La Tinta, Río Baracoa ( Spangler 1973, 1981); Niceto Pérez, Sierra de Canasta, Arroyo de los Berros ( Spangler 1981); Río Miel at Baracoa ( Spangler 1973); Baracoa, Yumurí, Río Yumurí ( Spangler 1981).

Diagnosis.

Small widely elongate species, body length 3.2-3.7 mm. Head dark, metallic; pronotum pale laterally, with large trilobite central dark spot, pronotal punctation not darkened laterally; elytra pale with dark intervals 8-10 and large transverse dark spots on posterior half of elyttral intervals 1-7. Elytral apices without subapical tooth, bumpy along suture subapically. Mesoventral process highly laminar, rectangular with large anterior and posterior teeth. Abdominal ventrite 1 with median keel throughout its length. Emargination of abdominal ventrite 5 rectangular with a median tooth. Median lobe of the aedeagus with long basal projection and beak-like apex in lateral view.

Differential diagnosis. For diagnostic characters and difference from Berosus chevrolati , see the latter species.

Redescription.

Habitus as in Figs 9a, b. Body length 3.2-3.7 mm. Body short and wide, moderately convex in lateral view. Labrum black, dorsum of head melanic with strong metallic luster. Antennae testaceous. Maxillary palpi testaceous with palpomere 4 dark at apex. Pronotum testaceous with unpaired metallic black spot, the spot expanding laterad posteriorly, and hence trilobite in general shape. Elytra testaceous with small ill-defined dark brown spots on disc and, a broad metallic dark area throughout lateral portion. Pro-, meso- and metafemora with pubescent portion dark brown, glabrous portion testaceous.

Head with moderately large and rounded punctures. Pronotum with punctures slightly larger than on head. Scutellum with few impressed punctures. Elytral striae distinctly impressed; intervals flat and wide, irregular long setae on elytra; spine-like setae absent. Elytral apices entire and rounded in both sexes; highly bumpy along suture, depressed laterally on sides. Mesoventral process raised, rectangular in shape, with hood-like anterior tooth, posterior tooth large (Fig. 9c). Metaventral process widely rectangular, with large and deep elongate glabrous median depression; posterolateral portions bulge-like, posterior projection pointed. Abdominal ventrite 1 with median carina throughout the length. Abdominal ventrite 5 with rectangular emargination bearing broad and sharp median tooth (Fig. 9g). Meso- and metafemora with pubescence covering basal 0.7 of total length, borderline between pubescent and glabrous portion sinuate. Protarsus of male with adhesive soles on tarsomeres 1-2, tarsomeres 1-2 distinctly thickened, tarsomere 3 elongate; tarsomere 4 2 × as long as tarsomere 3. Claws long, slender, slightly arched.

Male genitalia (Figs 9d-f). Phallobase ca. 0.7 × total length of aedeagus. Parameres in lateral view wide basaly, narrowing subapically and apically projecting into rounded apex, lacking setae. Median lobe G-shaped in lateral view, with long basal projection directing apicad; apex wide, beak-shaped in lateral view.

Distribution.

Dominican Republic and Cuba. The species was until now considered as Cuban endemic (e.g., Hansen 1999, Peck 2005), although Van Tassell (1966) mentioned specimens from the Dominican Republic. We are here confirming the occurrence of the species in the Dominican Republic based on recently collected specimens deposited in KSEM.

Habitat.

In our survey, the specimens of Berosus trilobus were collected usually in streams and rivers with stony or sandy bottom, clear water and with or without aquatic vegetation (Figs 11a, b), although once it has also been collected in a temporary pool with stony-muddy bottom, abundant organic matter, turbid water and rich submerged vegetation. Berosus trilobus is found in elevations ranging from sea level to ca. 850 m a.s.l.