Bembidion mimbres, Maddison, 2020

Maddison, David R., 2020, Shards, sequences, and shorelines: two new species of Bembidion from North America (Coleoptera, Carabidae), ZooKeys 1007, pp. 85-128 : 85

Bembidion mimbres sp. nov.

Holotype.

Male, in OSAC, labeled: "USA: New Mexico: Grant Co., Gila River, Billings Vista, 1320 m, 32.8163°N, 108.6032°W, 11.viii.2005. DRM 05.043. D.R. & J.H.A. Maddison", "David R. Maddison DNA2131 DNA Voucher" [pale green paper], "HOLOTYPE Bembidion mimbres David R. Maddison" [partly handwritten, on red paper], "Oregon State Arthropod Collection OSAC_0002000007 [matrix code]" [printed on both sides of white paper]. Genitalia in glycerin vial pinned beneath specimen; extracted DNA stored separately. GenBank accession numbers for DNA sequences of the holotype are MW151386, MW151400, MW151414, MW151425, MW151432, and MW151443.

Paratypes

(116). USA: New Mexico: Grant Co., Gila River, Billings Vista, 1320 m, 32.8163°N, 108.6032°W [Type locality] (44: OSAC, USNM, MCZ, NHMUK, MNHM, MSBA), USA: New Mexico: Grant Co., Billings Vista, Gila River, 1310 m, 32.8137°N, 108.6031°W (28: OSAC, CAS, UAIC, EMEC); USA: New Mexico: Grant Co., Gila River near Cliff, 1350 m, 32.9124°N, 108.5897°W (12: OSAC); USA: New Mexico: Grant Co., Gila River near Gila, 1370 m, 32.9692°N, 108.5868°W (3: OSAC); USA: New Mexico: Grant Co., Gila River near Gila, 1370 m, 32.969°N, 108.587°W (4: OSAC); USA: New Mexico: Grant Co., Gila River, Gila National Forest, 1315 m, 32.8167°N, 108.6035°W (14: OSAC); USA: New Mexico: Gila R., jct US 260, nr. Gila (1: UASM); USA: Arizona: Navajo Co., Carrizo Ck nr. Carrizo (10: UASM).

Type locality.

USA: New Mexico: Grant Co., Gila River, Billings Vista, 32.8163°N, 108.6032°W.

Derivation of specific epithet.

Bembidion mimbres is named in honor of the people of the Mimbres culture, who lived alongside this species, including at the type locality, and who illustrated the insects in their world on their pottery ( Hegmon, et al. 2018). The name is to be treated as a noun in apposition.

Diagnosis and description.

Adults of this species are relatively large Bembidion (5.3-6.3 mm in length), with a striking appearance because of the smooth and shiny dorsal surface with its metallic reflections (Figs 1 , 8B ). Body piceous, with an aeneous, green, or blue metallic reflection. Legs with tarsi and tibiae testaceous, femora infuscated. First three antennomeres testaceous, with the tip of the third infuscated in some specimens; fourth basally testaceous. Palps testaceous except for the penultimate maxillary article, which is infuscated. Mentum with anterior lateral regions large and triangular as typical for a Bembidion ; mentum tooth incised at tip, and thus bifid (similar to B. levigatum ). Prothorax with relatively straight sides, especially posteriorly (Fig. 8B ); with distinct posterolateral carina close to the lateral margin; posterior region of pronotum smooth, impunctate. Lateral bead of elytra extending inside shoulder well toward the midline, sharply angulate. Striae consisting of rows of distinct punctures, without an associated groove; on stria 1 complete; striae 2-6 absent in the posterior third; stria 7 virtually absent, represented by at most minute punctulae. Dorsal surface lacking microsculpture, and thus very shiny. More than two setae on the clypeus, and extra setae on the frons, at least anteriorly; at least one long seta near the front angle of the prothorax; prosternum with at most two setae. Elytra without the typical pair of distinguishable setose punctures associated with interval 3, but with a row of long setae on all intervals except 2 and 4. Aedeagus (Fig. 9C,D ) with ventral margin thinner, and with internal sac sclerites very similar to those of B. levigatum , but with slight differences, especially basally.

Most easily distinguished from B. levigatum by the narrower prothorax with straighter sides (Fig. 8B ), the lack of setae on elytral intervals 2 and 4, and having at most one or two setae on the prosternum.

Additional characteristics.

Diploid chromosome number 24, with 11 pairs of autosomes and an XY/XX sex chromosome system.

Geographic distribution.

Known from the Gila River watershed in Arizona and New Mexico (Fig. 10 ).

Habitat.

At the type locality, found at night on damp sandy soil about 2-4 meters from the river shore, in the shade of a large willow (Fig. 2 ). At a site a few meters away, 28 specimens were found at night on damp clay/sand soil among small Salix and Populus saplings 2-8 meters from the water’s edge; in spite of extensive searching in the same area, only one specimen was found during the day. At other sites along the Gila River, found in habitats similar to those in which B. levigatum is found, on damp sand and silt on the steep upper bank of the river, mostly at night.

Figures

Figure 1. Paratype male of Bembidion mimbres (voucher number V 100327) from the type locality.

Figure 2. Habitat of Bembidion mimbres at USA: New Mexico: Grant Co., Gila River, Billings Vista, 1320 m, 32.8163 ° N, 108.6032 ° W (type locality). Arrow indicates approximate location of most specimens. Found in the same habitat were Bembidion aratum (LeConte), B. impotens Casey, B. scintillans Bates, B. horni Hayward, B. rupicola (Kirby), B. clemens Casey, B rapidum (LeConte), and Omophron obliteratum Horn.

Figure 8. Adult males of subgenus Bembidion Hydrium A Bembidion levigatum (voucher V 100820, from USA: Utah: Grand Co., Moab, Colorado River, 1190 m, 38.5739 ° N, 109.5769 ° W) and B B. mimbres (a paratype from the type locality, voucher V 101458). Scale bars: 1 mm.

Figure 9. Male genitalia of subgenus Bembidion Hydrium A B. levigatum (voucher DNA 1693, Virginia: Danville City Co., Danville) B B. levigatum (voucher DNA 2343, Texas: Bastrop Co., Colorado River near Utley) C B. mimbres (voucher DNA 2134, USA: New Mexico: Grant Co., Gila River, Billings Vista) D B. mimbres (voucher DNA 2135, USA: New Mexico: Grant Co., Gila River, Billings Vista). Scale bar: 0.1 mm.

Figure 10. Geographic distribution of B. mimbres in Arizona and New Mexico.