Rhagodera costaefragmenta Krinsky

Krinsky, William L., 2015, A New Species ofRhagoderaMannerheim (Coleoptera: Zopheridae: Colydiinae) from San Clemente Island, California, The Coleopterists Bulletin 69 (2), pp. 293-296 : 293-294

Rhagodera costaefragmenta Krinsky , new species ( Figs. 1 , 4 )

Type Material. H o l ot y pe (se x u n k no w n) labeled “ CALIF.: San Clemente Is., indian shell mound, el. 1295′. 10 Aug.1968. (32°53′N, 118°31′W) leg. C.L. Remington & L.S. Matlovsky ” with author’ s red holotype label. Allotype (female) labeled “ CALIF.: San Clemente Is., highest terrace, 1 mi. N. of Pyramid Head. 11 November 1972 leg. C.L. Remington ” with author’ s red allotype label. Three paratypes (female plus two of unknown sex) each with same collection data as allotype plus the author’ s paratype label. All types are deposited in the Division of Entomology , Peabody Museum of Natural History , Yale University , New Haven , Connecticut.

Holotype. ( Fig. 1 ). Length 7.0 mm, width across middle of elytra 2.7 mm (2.6X longer than wide). T /W = 0.5. Color reddish brown to piceous; without surface luster. Head: Subquadrate (1.5 mm long); covered with small tubercles, each bearing a short, pale, scale-like seta; anterolateral angles strongly lobed over antennal insertion, elevated smaller lobe above each eye (most of eye visible from above), anterior vertex with triangular array of tubercles (slightly larger than those on rest of head) just anterior to higher distinct protuberance (appearing to be composed of a few fused tubercles). Eye posteriorly removed from antennal insertion. Length of third antennal segment equal to horizontal diameter of eye (0.4 mm). Antenna 11-segmented with 3-segmented club, last antennal segment emarginate. Subantennal groove distinct. Pronotum: 2.2 mm wide (1.5X length), lateral margins evenly arcuate, denticulate, apical and basal angles right, anterior margin evenly concave except where it is overlaid by rectangular central discal elevation, lateral margins of elevation interrupted by single notch. Anterior margin of elevation emarginate, posteror margin arcuate. Tubercles and lateral denticles each topped by a short, pale, scalelike seta. Few posterior lateral denticles broader, blunter, and more widely spaced than those forming rest of lateral pronotal margin. Elytra: Surface with sutural costa, 3 discal costae, and marginal costa. Sutural costa and discal costae 1 and 3 prominently elevated at their extreme bases, discal costae interrupted to different degrees: costa 1 well-defined on basal 1/3 of elytron, then with 4 interruptions before distal 1/5 of elytron where a well-defined portion begins and continues to the apex and joins apical margin; costa 2 absent and replaced by irregularly spaced, non-linearly arranged tubercles for 4/5 length of elytron, followed by a well-defined distal portion that ends before reaching apical margin; costa 3 well-defined and continuous from base to 4/5 length of elytron, ending at about same level at which distal segments of costae 1 and 2 begin. Intervals between costae with 2 rows of large, round, well-separated punctures. Venter: Procoxal cavities widely open behind. Epipleural fold ends near middle of penultimate ventrite, where an irregular carina composed of small tubercles begins and continues to apex of elytron.

Allotype. Female (ovipositor extended). Length 6.5 mm; width 2.2 mm. As holotype except in the following respects: color mostly piceous, with reddish brown on pronotal margins and legs. Antennal segment 3 equals 1.5X horizontal diameter of eye. Sutural costae less prominent at base. Distal portion of costae 1 and 2 less well-defined, shorter, and appearing as clumped tubercles, not reaching apical margin.

Variation. Female and two of unknown sex (paratypes). Length 6.5 mm; width 2.2–2.4 mm. Color piceous with some parts reddish brown (mostly pronotal lateral margins and legs). Antennal segment 3 equals 1.2X horizontal diameter of eye. Poorly defined distal portions of costae 1 and 2 and costa 1 not reaching apical margin similar to allotype.

Etymology. The name is derived from the Latin costae (lit. “ribs”), referring to the raised ridges on the elytra, and the adjective fragmentum meaning “fragment” or “remnant”. The name is descriptive of the fragmented elytral costae.

Diagnosis. Rhagodera costaefragmenta most closely resembles R. interrupta and R. tuberculata , both of which have the epipleural fold ending near the middle of ventrite IV, followed by a thin carina to the apex. Rhagodera costaefragmenta differs from R. tuberculata and R. interrupta by the extremely fragmented costa 2 ( Figs. 2–4 ). A subantennal groove is present in R. costaefragmenta and R. tuberculata but absent in R. interrupta . The following key to species is adapted from Stephan (1989) to accommodate R. costaefragmenta .

Figures

Fig. 1. Rhagodera costaefragmenta, holotype, dorsal habitus.

Figs. 2–4. Comparison of costa 2 in three species of Rhagodera. 2) R. tuberculata; 3) R.interrupta; 4) R. costaefragmenta.