Bembidion nitidicolle Bousquet

Bousquet, Yves & Webster, Reginald, 2006, Descriptions of three new species of Bembidion Latreille (Coleoptera: Carabidae) occurring in Canada, Zootaxa 1297, pp. 23-35 : 32-34

Bembidion nitidicolle Bousquet , sp. nov.

( Figs. 2 , 5 )

Etymology. The species name derived from the Latin adjective nitidus, ­ a, ­ um (shiny, smooth) and noun collum, ­ i, n (neck), in reference to the smooth (without microsculpture) pronotum.

Type Material. Holotype (ɗ) in CNC labelled: "Rosefield Sask. (s.e. of Val Marie) 27–V–1986 K. Roney / on prairie dog mound / Bembidion n.sp. nr. constricticollis Hay. det. D. Shpeley 1986 / Holotype Bembidion nitidicolle Bousquet CNC no. 23457." Rosefield is a postoffice now in Grassland National Park (R. Hooper, personal communication).

Paratypes from the following localities. SASKATCHEWAN. Same data as holotype (3ɗɗ, 5ΨΨ, CNC). SOUTH DAKOTA. Fort Pierre, Stanley Co., 3.VI.1979, C.v. Nidek (1ɗ, UASM).

Description. Habitus ( Fig. 2 ). Color: Head and pronotum brownish­red to reddishbrown, with head darker than pronotum in some specimens; elytra yellowish­red to brownish­red with the medial intervals (except first one and toward apex) darker in most specimens seen; antennomeres uniformly brownish­red to reddish­brown; palpi paler, yellow to reddish­yellow; legs ± uniformly yellow to reddish­yellow. Microsculpture: Clypeus, frons and pronotum without meshes; elytra with relatively poorly impressed isodiametric meshes, these distinct only over apical third to apical fifth; abdominal sterna with well impressed isodiametric meshes. Vestiture: Head and pronotum without distinct microtrichia; elytral intervals each with row of sparse microtrichia, barely distinct at 80x; prosternum, metasternum and abdominal sterna with sparse microtrichia. Head: Eyes proportionally slightly smaller than in B. constricticolle . Prothorax: Pronotum markedly constricted at base, as much as in B. constricticolle . Elytra: Strial punctures moderately coarsely punctate, distinct up to near apex. Male genitalia: Median lobe as illustrated ( Fig. 5 ).

Apparent body length = 3.7–4.1 mm.

Geographical Distribution. This species is known only from southern Saskatchewan and central South Dakota.

Wing Development. This species is wing­dimorphic. Of all the specimens seen, one had fully developed wings with reflexed apices, the other ones had reduced wings without reflexed apices.

Habitat. All the specimens of the type­series, except that from South Dakota, had labels reading "on prairie dog mound."

Note. This species belongs to the constricticolle group as defined by Lindroth (1963: 346), which includes only two other species: B. constricticolle Hayward and B. nudipenne Lindroth. Adults of B. nudipenne differ from those of B. nitidicolle in having well impressed microsculpture meshes on the clypeus, frons, lateral half and base of pronotum and on the elytra, the pronotum less constricted basally, and the prosternum, disc of metasternum and abdominal sterna (except last one in females) without distinct microtrichia. The wings seem constantly fully developed in B. nudipenne ( Lindroth 1963: 347) . Adults of B. constricticolle differ from those of B. nitidicolle in having the elytra much paler, ± yellow with the medial intervals (often only over anterior half) and a median transverse band darker, reddish­brown, in having microtrichia over the dorsal surface of the head and pronotum and in having the microtrichia over the elytral intervals longer, distinct even at 20x.

Contrary to most groups of Bembidion defined by Lindroth (1963), the constricticolle group has no subgeneric name. In our opinion, the group deserves one and therefore the senior author proposes the subgeneric name Neobembidion Bousquet, subg. nov. [type species: Bembidion constricticolle Hayward, 1897 ]. Members of the subgenus possess the following character states: integuments without metallic lustre; frontal furrows shallow, not extended on clypeus; antennomeres 5–10 stout; mentum tooth relatively small; gena with microtrichia; pronotum markedly constricted basally, side with deep sinuation in basal half; anterior angle of pronotum not projected anteriad; posterior angle of pronotum about right; lateral depression relatively wide, well defined over entire length of pronotum; laterobasal carina of pronotum short but well defined; lateral edge of elytron not angularly prolonged beyond humerus; striae ± obsolete toward apex, punctures moderately coarse; intervals each with row of microtrichia, well distinct in B. constricticolle , ± distinct in the other two species; interval 3 with two discal setae (ed3 and ed5) free, not attach to stria 3.

Figures

FIGURE 2. Bembidion nitidicolle, habitus (dorsal view). Scale bar = 1 mm.

FIGURES 3 – 5. Median lobe of aedeagus (left lateral view). 3, B. nigrivestis (Rigaud, Quebec); 4, B. iridipenne (holotype); 5, B. nitidicolle (Rosefield, Saskatchewan). Scale bar = 0.2 mm.