Carcinops curtus Reese and Swanson, 2017

Reese, Ellen M. & Swanson, Alexander P., 2017, A Review of the CactophilicCarcinopsMarseul (Coleoptera: Histeridae) of the Sonoran Desert Region, with Descriptions of Six New Species, The Coleopterists Bulletin 71 (1), pp. 159-190 : 171-173

Carcinops curtus Reese and Swanson , new species ( Figs. 9F , 10E , 16 )

Type Series. HOLOTYPE. Male. “ MEXICO: Sonora, San Carlos/ 27.97070°N 110.99825°W / sea level, 19.III.2007 / ex. necrotic Stenocereus thurberi / A. Swanson, APS168” ( UNAM; DNA voucher: APS168). PARATYPES. 20 specimens. Same data as holotype ( APS, 1; CASC, 2; FMNH, 2; USNM, 1; DNA voucher: APS 148), MEXICO: Sonora, Magdalena, 30.61147°N 110.97425°W, 780m, 19.III.2007, ex. necrotic Stenocereus thurberi, A. Swanson ( MCZ, 1; CASC, 1; FMNH, 1; USNM, 1; DNA voucher: APS 130). MEXICO: Baja California Sur. nr. La Paz, 23.8257°N 110.272°W, sea level, 7.XII.2012, ex. necrotic Stenocereus thurberi, E. Reese ( FMNH, 3; LSAM, 1), MEXICO: Baja California Sur. nr. La Paz, 23.8379°N 110.1908°W, sea level, 8.XII.2012, ex. necrotic Pachycereus pringlei, E. Reese ( CASC, 1; FMNH, 3), MEXICO: Baja California Sur. nr. La Paz, 23.4735°N 109.5657°W, sea level, 8.XII.2012, ex necrotic Stenocereus thurberi, E. Reese ( FMNH, 1).

Diagnosis. This species is distinguished by the following combination of characters. Head: Frontal stria terminating at anterior margin of eye, not reaching mandibles ( Fig. 5B ); marginal epistomal stria absent. Pronotum: Marginal stria sinuate and broadly divergent from anterior edge along midline ( Fig. 5A ). Elytra: Dorsal stria 5 and sutural stria subequal in length to dorsal striae 1– 4, reaching or nearly reaching proximal base of elytra ( Fig. 7 ); internal subhumeral striae present; external subhumeral striae absent or reduced to row of faint punctures. First abdominal ventrite:

One stria present, smooth surface texture ( Fig. 2A ). Aedeagus: Parameres straight and sharply pointed at tips ( Fig. 9F ).

Description. L: 1.98 mm; W: 1.36 mm; E/Pn L: 1.54; E/Pn W: 1.13; Pn W/L: 1.54; E L/W: 0.88; Sterna: 0.58, 0.16, 0.52 mm. Form elongateoval, moderately depressed; color black to rufous, shiny. Frons slightly convex, densely punctate with mixture of coarse and fine punctures; frontal stria interrupted anteromedially, extending anterad to anterior margin of eye; marginal epistomal stria absent.

Pronotum moderately convex, widest at base; anterior angles acute, projecting; pronotal marginal stria complete to base, sinuate behind head where it is about 3 times as distant from anterior margin of pronotum than along interior margin of anterior angles; pronotal disc finely densely puncate in medial third, with coarse punctures somewhat sparsely distributed throughout lateral thirds to lateral margins; posterior margin marked by a row of coarse, round punctures; antescutellar puncture round, strongly impressed.

Prosternal lobe more densely punctate toward anterior margin, punctation fine and sparse posteromedially; prosternal keel flat to slightly concave; carinal striae slightly inwardly arcuate and united posteriorly.

Elytra finely, sparsely punctate, punctation more dense toward suture; coarse punctures most dense at elytral apices, sparsely scattered basad to apical third; epipleuron with a few coarse punctures in apical half; marginal elytral stria arcuate, parallel to marginal epipleural stria before abruptly converging near elytral apex, outer edge subcariniform; external subhumeral stria represented by a row of 3–6 faint punctures along middle third; internal subhumeral complete except where broken by oblique subhumeral stria; 1 st –4 th dorsal striae complete, strongly impressed, serially punctate at regular intervals, slightly inwardly arcuate; 5 th dorsal stria more inwardly arcuate, curving to meet sutural stria, fading to a row of punctures at about basal fourth before terminating near elytral proximal base, sutural stria strongly impressed at elytral apices, fading basad to meet 5 th dorsal stria near elytral base as a row of faint punctures.

Mesosternum finely, densely punctate; anterior margin feebly emarginate to receive prosternal projection; marginal stria complete, deeply impressed, continuous with internal lateral metasternal striae; mesometasternal suture represented by a fine line; intercoxal disc of metasternum finely, densely punctate with distinct patches of coarse punctures confined to posterolateral areas; lateral metasternal stria straight, strongly impressed, nearly reaching outer margin of metacoxal cavity; posterior mesocoxal stria widely separated from lateral metasternal, curving slightly medially at posterior apex, nearly reaching outer margin of metacoxal cavity; lateral disc with a few coarse punctures.

Intercoxal disc of 1 st abdominal ventrite coarsely and moderately densely punctate throughout; bistriate on each side medial to hind coxae; punctures of lateral disc coarse, sparse and round; surface smooth, not microrugulose, bearing a single stria along outer margin.

Outer margin of protibia bidentate in distal half; denticles acute, projecting well beyond tibial margin; outer margin of mesotibia tridentate with 2 denticles inserted near the tibial apex and a third inserted just proximal to the midpoint of the outer margin; outer margin of metatibia bidentate, both denticles inserted near tibial apex.

Parameres of aedegus narrowed, tapering to acute point, about half as long as basal piece ( Fig. 9F ).

Comparison with Related Species. This species is most similar to C. rugulus and C. torquatus . It can be distinguished from both species by the extent of the anteromedial interruption of the head frontal stria. In C. curtus , the extent of the interruption is greatest, with the frontal stria not extending anterad beyond the anterior margin of the eye ( Fig. 5B ). In both C. rugulus and C. torquatus , this stria extends anterad to the clypeolabral suture ( Fig. 3B ). Carcinops curtus also differs from C. rugulus and C. torquatus in the reduction of the external subhumeral striae to a row of three to six faint punctures.

Geographic Distribution and Natural History. Carcinops curtus is known from several localities throughout Sonora and Baja California Sur, Mexico and at Organ Pipe National Monument, Arizona. This species exhibits a strong association with necroses of Stenocereus thurberi (Engelm.) Buxb. , but has also been found in necroses of P. pringlei .

Additional Material Examined. 35 specimens. MEXICO: Baja California Sur: nr. La Paz, 23.8257°N 110.272°W, sea level, 7.XII.2012, ex. necrotic Stenocereus thurberi, E. Reese (EMR, 5; DNA voucher: EMR016), nr. La Paz, 23.4735°N 109.5657°W, sea level, 8.XII.2012, ex. necrotic Pachycereus pringlei, E. Reese (EMR, 5; DNA vouchers: EMR023, EMR024), nr. La Paz, 23.4735°N 109.5657°W, sea level, 8.XII.2012, ex. necrotic Stenocereus thurberi, E. Reese (EMR, 5; DNA voucher: EMR049), nr. La Paz, 23.83675°N 110.26765°W, sea level, 29.VI.2013, ex. necrotic Stenocereus thurberi, E. Reese (EMR, 14; DNA voucher: EMR264). USA: Arizona: Organ Pipe National Monument, 29.X.2003, ex. necrotic Stenocereus thurberi, Vergara (APS, 6).

Derivation of Specific Epithet. This species is named for the relative shortness of its frontal stria. Types deposited by APS were labeled as “ Carcinops stenocereus ” as the species was believed at the time to exclusively inhabit necroses of S. thurberi . The species was later found in P. pringlei by EMR, and so we elected to describe the species under the more suitable name C. curtus , which reflects the species’ relatively short frontal stria. Type specimens deposited by APS have been updated with the correct name.

Figures

Fig. 9. Aedeagal morphology of Carcinops species, with parameres toward the top of the page and basal pieces toward the bottom. A) C. consors, B) C. gilensis, C) C. corticalis, D) C. papagoanus, E) C. opuntiae, F) C. curtus, G) C. rugulus, H) C. torquatus, I) C. yaqui, J) C. wenzeli. Photographs by A. Swanson.

Fig. 10. Dorsal photographs showing head and pronotal morphology of Carcinops species. A) C. consors, B) C. gilensis, C) C. corticalis, D) C. papagoanus, E) C. curtus, F) C. yaqui, G) C. kumeyaay, H) C. opuntiae. Photographs by E. Reese.

Fig. 16. Carcinops curtus morphology. A) Dorsal view, B) Ventral view. Photographs by E. Reese.

Figs. 3–6. Head morphology of Carcinops kumeyaay, with arrows showing key character states: 3) C. kumeyaay; 4) C. corticalis; 5) C. curtus. Photographs by E. Reese. 6) Ground punctation patterns on the pronotum of species in the subgenus Carcinopsida (Carcinops wenzeli). Photograph by A. Swanson.

Figs. 7–8. 7) Long elytral striae highlighted on Carcinops kumeyaay; 8) Short fifth and sutural elytral striae highlighted on Carcinops yaqui. Photographs by E. Reese.

Fig. 2. Variation of the lateral disc of the first abdominal ventrite in Carcinops species. A) Single stria present (C. torquatus), B) Single stria with microsculptures present (C. rugulus), C) Bistriate (C. consors), D) Bistriate (C. yaqui), E) Tristriate (C. wenzeli). Photographs by A. Swanson.