Bembidion ricei Maddison & Toledano

Maddison, David R. & Toledano, Luca, 2012, A new species of Bembidion (Ecuadion) from Ecuador (Coleoptera, Carabidae, Bembidiini), with a key to members of the georgeballi species group, ZooKeys 249, pp. 51-60 : 53-57

Bembidion ricei Maddison & Toledano sp. n.

Holotype.

Adult male, with three labels: "ECUADOR: Napo: Rio Chalpi Grande, 2800m, 0.3645°S, 78.0852°W, 26.x.2010. DRM 10.159. W.P. & D.R. Maddison, M. Reyes", "David R. Maddison DNA2653 DNA Voucher [printed on pale green paper]", and "HOLOTYPE Bembidion ricei Maddison & Toledano [printed on red paper]". Specimen to be deposited at QCAZ; temporarily in OSAC. Genitalia in glycerine in vial pinned beneath specimen. GenBank accession numbers of DNA sequences from the holotype: JX971116 (28S ribosomal DNA) and JX971117 (cytochrome oxidase I).

Paratypes.

Six males and nine females from: ECUADOR: Napo: Rio Chalpi Grande, 2800m, 0.3645°S, 78.0852°W, 26.x.2010 & 8.xi.2010 (11 exx., OSAC, BMNH, MNHN); ECUADOR: Napo: Papallacta, 2750 m, Rio Chalpi, 8.xi.1985 (1 ex., CTVR); ECUADOR: Napo: Rio Guango (=Rio Huango), 2730m, 0.3758°S, 78.0748°W, 26.x.2010 (2 exx., OSAC); ECUADOR: Napo: Sierrazul (Hacienda Aragon) 10 km W of Cosanga, 2250m, 3-4.vi.1993, 00°44'08"S, 077°53'50"W (1 ex., USNM).

Type locality.

ECUADOR: Napo: Rio Chalpi Grande, 2800m, 0.3645°S, 78.0852°W.

Derivation of specific epithet.

It gives us great pleasure to name this species after the late Harold Edward Rice, a passionate butterfly collector and active member of the Pacific Northwest lepidopterist community, and friend to the senior author. Through Harold’s generosity, systematic entomology is well supported at Oregon State University. The fund he established paid for the expedition that yielded most of the known specimens of Bembidion ricei , including the holotype.

Diagnosis.

A shiny, medium-sized Bembidion (Ecuadion) with convex elytral intervals, and with a mottled pattern of light and dark on the elytra (as in Fig. 2A); adults have a seta at the hind corner of the pronotum, and lack elytral microsculpture in both males and females. Stria 3 and stria 4 are joined together and interrupted in front of the anterior discal seta (ed3; Fig. 2A, 4A); the striae are otherwise complete, and deeply engraved. This combination of characteristics is distinct within the genus.

Brown, with lateral margins of pronotum paler brown in most specimens, and with elytra having a pale apex, and a pale transverse preapical region surrounded by darker brown (Fig. 2A); the region adjacent to ed3 is also slightly darker. Prothorax with sinuate lateral margin, hind angles about 90°, and with a posterior lateral carina (Fig. 3A). Elytral striae deep, complete, although with striae 3 and 4 joined together and interrupted in front of ed3 (Fig. 4A) in all 16 specimens examined; elytral intervals convex. Microsculpture absent from the pronotum and elytra in both sexes. Aedeagus as in Fig. 5A. ABL 3.9-4.1mm, n=6.

One of the more unusual aspects of these Bembidion , shared with some other Ecuadion , including males of Bembidion georgeballi , is the amber-like clarity of the elytra. The elytra are similar to clear lacquer in places, allowing bright microsculpture dots from the undersurface of the elytra to be visible dorsally (see pale dots in Fig. 4C).

The only other Ecuadion with yellow and brown mottled elytra, and with complete striae and convex elytral intervals, are Bembidion georgeballi and Bembidion pierrei ( Toledano 2008). Bembidion ricei is most similar to Bembidion georgeballi , sharing more convex elytral intervals, and pale lateral regions of the pronotum in most specimens. Specimens differ in being larger (ABL 3.9-4.1mm in Bembidion ricei , 2.9-3.4mm in Bembidion georgeballi ), with a less constricted posterior margin of the pronotum (compare Fig. 3A to 3B). The posterior lateral set a and carina of the pronotum are present (absent in Bembidion georgeballi ). Bembidion ricei specimens have striae 3 and 4 joined and interrupted in front of discal seta ed3 (Fig. 4A). Microsculpture is lacking from the dorsal surface of the elytra in both males and females of Bembidion ricei , and thus they are very shiny (Fig. 4A, C); in Bembidion georgeballi , males lack elytral microsculpture, but females have evident isodiametric microsculpture throughout the elytra (Fig. 4B, D). In addition, the male aedeagus of Bembidion ricei has larger and darker sclerotized regions on the internal sac (Fig. 5A). Bembidion georgeballi is currently known only from 3350-3550m on the slopes of Volcán Guagua Pichincha west of Quito (Fig. 1).

From Bembidion pierrei , Bembidion ricei can be distinguished by having striae 3 and 4 joined, and lacking microsculpture on the elytra ( Bembidion pierrei has isodiametric microsculpture throughout the elytra in both males and females). Bembidion pierrei also lacks the transparent, lacquer-like elytral regions of Bembidion ricei . Bembidion pierrei is known from the province of Chimborazo, far south of the localities of known localities of Bembidion ricei (Fig. 1).

Geographic distribution.

Bembidion ricei occurs in the province of Napo between 2250m and 2800m in the Andes of Ecuador, east of Quito (Fig. 1). Most specimens have been found a few kilometers east of Papallacta along two tributaries of the Rio Papallacta; a single female has been found along a tributary of the Rio Jondachi south of Cosanga and west of La Merced de Jondachi.

Habitat.

Found among leaf litter and under rocks in moist areas near small streams in montane forest (Fig. 6). Specimens were found during daytime in leaf litter under rocks or by scratching open leaf litter.