Hemiosus exilis ( LeConte, 1852 )

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 : 8-9

Hemiosus exilis ( LeConte, 1852)

( Fig. 4 )

Berosus exilis LeConte, 1852: 211 .

Hemiosus toxillus d’Orchymont, 1940: 181 . New synonomy. Hemiosus exilis: Leech, 1943: 61 ; Van Tassell, 1964: 54.

Type material examined. Berosus exilis LeConte : Holotype (male): [colored disc], “ B. exilis / Lec./ Gila”, “ Type / 3081 ” ( MCZ).

Hemiosus toxillus d’Orchymont : holotype (male): “[male symbol]”, “Mex. Mazatlan/ brack, pools 25 / v. 1934 H. Hinton”, “A. d’Orchymont det./ Hemiosus / toxillus m.”, “ TYPE [red card]” ( IRSNB). Paratype: “Female symbol”, “Sinaloa/ Mex”, “Para-/ type [orange card]”, “ Hemiosus toxillus / Orchymont/ Tete Manque” ( IRSNB).

Additional material examined (69). MEXICO: Sinaloa: Culiacan, 16.vii. 1963, P.J. Spangler leg. (60: AEZS, NMW, USNM); Jalisco: Rio Cuitzmala, SE of Chamela, 180 ft. asl, 6.i. 2005, W.D. Shepard leg. (7: AEZS); 6.6 km SE Villa Purificacion, Puente El Amorin, 8.i. 2005, W.D. Shepard leg. (1: AEZS); Veracruz: 29 mi. SE Jalapa, 900 ft., 26.xii. 1963, M.J. Tauber & C.A. Tauber leg. (1: EMEC).

Diagnosis. Total length: 2.3–2.8 mm. The broadly testaceous anterior and lateral margins of the pronotum ( Fig. 4 ) serve to distinguish this species in Mesoamerica.

Distribution. Mexico, United States (Arizona, Texas).

Remarks. See Van Tassell (1964) for a detailed discussion of the taxonomic history of the species. The synonymy of H. toxillus d’Orchymont with H. exilis (LeConte) was first recognized but unpublished by Van Tassell (1966). I have examined the holotypes of both species and concur that H. toxillus d’Orchymont and H. exilis (LeConte) are conspecific. This likely occurred because H. exilis was still placed in the genus Berosus when d’Orchymont (1940) described H. toxillus . A full description and additional illustrations of this species are given by Oliva (1991) under the name H. toxillus .

Figures

FIGURES 3 – 5. Details of Hemiosus selva Short, sp. n. (3, 5) and H. exilis (LeConte) (4). 3 – 4: pronotal coloration, scale bar 0.18 mm; 5: aedeagus, scale bar 0.2 mm.