Athoplastus rainieri Etzler & Johnson 2018, new combination

Athoplastus rainieri (Van Dyke, 1932), new combination

(Adult: Figs. 4, 8, 22–24, 28)

Ludius rainieri Van Dyke 1932: 397, 421.

Ctenicera rainieri (Van Dyke, 1932); Lane 1971: 32.

Diagnosis. This species is distinguished from all other species of the genus by the combination of close pronotal punctures (separated by less than one diameter of a puncture) (Fig. 10), sloped prosternum (Fig. 8), and dark markings at each puncture along the striae of the elytra (Fig. 4). This last character is likely not a good species-level character and may be related to specimen development. Athoplastus rainieri is quite similar to A. palouse, which can be distinguished as noted above.

Description. Male. Length 16 mm, width 4 mm (measured across bases of elytra). Red-brown, carina and tips of mandibles darker; antennae, palps, coxae, and tarsi lighter, almost tawny yellow (Fig. 4). Head: Ocular index = 61.1. Antennae: Ratio of antennomeres (2–11): 1: 1.25: 3: 3.25: 3.5: 3.25: 3.75: 2(?): X: X. [Antennomere 9 appears to be broken, and 10 and 11 are missing on the specimen measured.] Pronotum: 1.1X wider than long. Lateral margin completely carinate, slightly sinuate, almost subparallel anterad hind angles; convergent and slightly dorsoventrally flattened along lateral edges on anterior fourth. Punctures distinct, subumbilicate and dense on disc, separated by less than 0.2X their own diameter, with 2 “dimples” on either side of midline just anterad midlength, with less close punctures; punctures becoming clearly umbilicate and denser along anterior and lateral margins. Prosternum: Slightly convex with dense, shallow, umbilicate punctures; anterior lobe short, broadly rounded, shallowly deflexed. Posterior process short and arcuate, gradually raised ventrally between procoxae, then sharply deflexed posteriorly; distinct ridge present immediately before procoxal cavity and along ventral surface of prosternal process. Legs: Tarsomere 5 equal to tarsomere 1 on pro- and mesotarsi, tarsomere 5 missing on both metatarsi. Elytra: Elongate, subparallel, 4X pronotal length; striae shallowly impressed, deeper apically, punctures marked by darkening of the integument; intervals shallowly convex, punctures fine, shallow, and irregularly distributed. Aedeagus (Figs. 22–24): Basal piece approximately 1/3 total length, with deep, narrowly U-shaped, membranous section on ventral surface (Fig. 23); median lobe 1.2X length of parameres, slightly deflexed ventrally at tip, median carina on ventral surface, basal struts following edges of median lobe; parameres wide basally, edges slightly sinuate and gradually narrowing toward tip, tip with subacute lateral expansion bearing 2 setae (Fig. 24).

Female. Length 21 mm, width 5 mm (measured across bases of elytra). Yellow-brown. Head: Ocular index = 72.7. Antenna: Ratio of antennomeres 2–11: 1: 1.6: 2.2: 2: 1.8: 1.6: 1.8: 1.6: X: X: X. [Note: Antennae are broken on specimen examined, so the last three antennomeres of longest intact antenna are missing.] Pronotum: 1.25X wider than long, hind angles divergent, sides broadly sinuate. Legs: Tarsomere 5 intermediate in size between tarsomeres 1 and 2 on metatarsi; pro- and mesotarsi as in male. Scutellar shield: Setae radiating from midline.

Specimens Examined (3). Male. Holotype. USA: WASHINGTON: [Pierce Co.]; Mt. Rainier [E.C. Van Dyke, date unknown] (CASC, 1, CASC type no. 3181). Female. USA: WASHINGTON: [Kittitas Co.] Lk. Cle Elum; 13.v.1936; M.C. Lane (1, USNM); Lk. Cle Elum [?], 26.v.1937, M.C. Lane (1, USNM).

Distribution. This species is only known from the Cascade Range of mountains in Washington.

Taxonomic Remarks. Van Dyke (1932) mentions a specimen seen “in the collection of Prof. W. J. Chamberlin at Corvallis, Oregon.” Chamberlain’ s collection was deposited at the Oregon State Arthropod Collection (OSAC) at Oregon State University (Oman 1970). However, a search of the OSAC yielded no specimen matching this description.