Hemiosus maculatus Sharp, 1882

Short, Andrew Edward Z. & Torres, Phillip J., 2006, Review of the Hemiosus Sharp and Derallus Sharp of North America, Central America, and the Caribbean (Coleoptera: Hydrophilidae: Berosini), Zootaxa 1369, pp. 1-17 : 4-6

Hemiosus maculatus Sharp, 1882

( Figs. 1–2 )

Hemiosus maculatus Sharp, 1882: 85 .

Type material examined. Syntypes (8 examined): “ Hemiosus macula-/ tus. Type D.S./ Guatemala Champion”, “ Type [red disc]”, “ Guatemala / Champion.”, “Sharp Coll./ 1905.

– 313 ”, “B.C.A. Col. I. 2. / Hemiosus / maculatus, Sharp. ” ( BMNH); [2 specimens on card], “Pantaleon,/ 1700 ft./ Champion.”, “B.C.A. Col. I. 2. / Hemiosus / maculatus, Sharp. ”, “ Hemiosus maculatus ”, “SYN-TYPE [light blue disc]” ( BMNH); “ Hemiosus / maculatus / D.S./ Pantaleon 1700 ft./ Champion [same card as 2 specimens]”, “Sharp Coll./ 1905. – 313 ”, “Pantaleon,/ 1700 ft./ Champion.”, “B.C.A. Col. I. 2. / Hemiosus / maculatus, Sharp. ”, “SYN-TYPE [light blue disc]” ( BMNH); “[male symbol]”, “Pantaleon,/ 1700 ft./ Champion.”, “B.C.A. Col. I. 2. / Hemiosus / maculatus, Sharp. ”, “Para-type [orange card]” ( IRSNB); “Pantaleon,/ 1700 ft./ Champion.”, “B.C.A. Col. I. 2. / Hemiosus / maculatus, Sharp. ”, “Para-type [orange card]” ( IRSNB).

Additional material examined (262). BELIZE: Belize District: Western Highway near Zoo, light trap in pine grassland, 7.i. 2003, C.R. Bartlett leg. (3: AEZS); Cayo District, near Teakettle Bank, Pook’s Hill, light trap at river, (5–6). i. 2003, C.R. Bartlett leg. (12: AEZS). COSTA RICA: Alajuela: near San Ramon, roadside pools near Quebrada Negra, 13.vii. 1999, R.E. Roughly leg. (1: UMC); Guanacaste: Rio Guacimal at Highway 1, 400 ft., 17.vi. 2003, A.E.Z. Short leg. (37: AEZS, INBio); Rio Carmona, near Carmona at Finca Aqua Fria, HG-vapor light, 30 m, 15.i. 2003, A.E.Z. Short, R. Roughley & W. Porras leg. (17: AEZS, INBio); same locality but 26.xi. 2002 (2: AEZS); Nandayure, Finca Aqua Fria, 0–100 m, 19.i. 2002, W. Porras leg. (1: INBio); Puntarenas: Corcovado National Park, Sirena Station, 5 m, 1.vi. 1992, UV light, Z.H. Falin leg. (3: CUIC); N of Cirvelas, Rio Seco at Highway 1, pools along river, 17.vii. 2003, A.E.Z. Short leg. (70: AEZS, INBio); Golfito, Sector El Tajo, 100–200 m, 28.iv. 2004, light trap, W. Porras, B. Gamboa, D. Briceno & M. Morgaga leg. (4: INBio); Osa Peninsula, Rio Conte, 18.3 km NW of Puerto Jimenez, 18.vi. 2003, A.E.Z. Short leg. (22: AEZS, INBio); Rio Tigre near Puerto Jimenez, black light, 18.vi. 2003, A.E.Z. Short leg. (40: AEZS, INBio). HONDURAS: Lancetilla, nr. Tela, 19.vi. 1979, at light, J.A. Chemasak, A. & M. Michelbacher, & W. Middelkauff leg. (2: AEZS, EMEC). MEXICO: Jalisco: Chamela Biological Station, 21–22.x. 1987, black light, Chemsak & Powell leg. (39: AEZS, EMEC); Sinaloa: 21 mi. E Villa Union, 300 ft., 25.vii. 1964, lights, Chemsak & Powell leg. (3: EMEC); Sonora: 5 mi. W Alamos, 14.viii. 1959, Werner & Nutting leg. (2: AEZS); Alamos, 15.vii. 1963, P.J. Spangler leg. (2: AEZS); Sinaloa State: Culiacan, at black light, 16.vii. 1963, P.J. Spangler leg. (1: AEZS). NICARAGA: Managua, km 45.8 of Pan-Am Highway, 430 ft., stream, 4.viii. 2002, W.D. Shepard leg. (1: AEZS). Representative material deposited in MALUZ, MIZA, MFPC and NMW.

Differential Diagnosis. Total length: 2.3 –3.0 mm. The entirely melanic, iridescent pronotum easily distinguishes this species from all others in Central America ( Figs. 1–2 ). There is no detectable external sexual dimorphism.

Variation. The elytral maculae can vary substantially both in size and intensity both within and between populations. It would not be a surprise to us if this species is found to be composite in the future.

Distribution. From southern Mexico into South America, including Belize, Costa Rica, Guatemala, Honduras, Mexico, Nicaragua, Panama, and Peru.

Remarks. A full description and additional illustrations of this species are provided by Oliva (1991). In Costa Rica, this species was frequently collected in the margins and backwaters of sandy-bottomed streams, as well as shallow, isolated pools with sandy substrate along the margin of streams and rivers. It also is attracted to lights near such habitats.

Figures

FIGURES 1 – 2. Dorsal and lateral habitus of Hemiosus maculatus Sharp (specimen from Costa Rica). Scale bar 2.1 mm.