Carcinops torquatus Reese and Swanson
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: 175-177
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|Carcinops torquatus Reese and Swanson|
Carcinops torquatus Reese and Swanson , new species
Type Series. HOLOTYPE. Male. “ MEXICO: Sonora, Arroyo Santa / Barbara nr. Alamos , 27.09443°N / 108.71266°W, 900m, 30.V.2007 / ex. necrotic Stenocereus montanus / A. Swanson, APS142 ( UNAM; DNA voucher: APS142) GoogleMaps . PARATYPES. 3 specimens. Same data as holotype ( FMNH, 1); MEXICO: Sonora, Arroyo Santa Barbara nr. Alamos , 27.11547°N 108.70767°W, 1400m, 3.VI.2007, ex. necrotic Opuntia sp. cladode GoogleMaps ,
A. Swanson ( APS, 1; CASC, 1; DNA voucher: APS 172).
Diagnosis. This species is recognized by the following combination of characters. Head: Frontal stria terminating at clypeolabral suture; marginal epistomal stria absent ( Fig. 3B View Figs ). Pronotum: Marginal stria sinuate and broadly divergent from anterior edge along midline ( Fig. 5A View Figs ). 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 View Figs ); internal subhumeral striae present; external subhumeral striae present, often reduced to row of punctures. First abdominal ventrite: One stria present, smooth surface texture ( Fig. 2A View Fig ). Aedeagus: Parameres straight and sharply pointed at tips ( Fig. 9H View Fig ).
Description. L: 2.04 mm; W: 1.46 mm; E/Pn L: 1.49; E/Pn W: 1.11; Pn W/L: 1.61; E L/W: 0.84; Sterna: 0.64, 0.22, 0.64 mm. Form elongate oval, somewhat depressed; color black, shiny; frons slightly convex, finely, densely puncate; frontal stria interrupted anteromedially, extending anterad just beyond antennal insertion to clypeolabral suture; marginal epistomal stria absent.
Pronotum convex, widest at base, sides feebly arcuate; 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 punctate in medial third, coarsely, somewhat sparsely punctate in lateral thirds with fine punctures interspersed; posterior margin rounded, marked by a row of coarse, round punctures; antescutellar puncture round, strongly impressed.
Prosternal lobe coarsely, densely punctate throughout, strongly convex posteriorly; prosternal keel moderately convex; carinal striae slightly inwardly arcuate, united posteriorly.
Elytra finely, moderately densely punctate; coarse punctures generally confined to a narrow band along elytral apices, though some are distributed basad between sutural striae and elytral suture; epipleuron strigosopunctate; epipleural marginal stria slightly more outwardly arcuate than elytral stria, striae beginning to converge apically at about midpoint of epipleuron; outer edge of elytral stria cariniform; external subhumeral striae strongly impressed from about apical fourth to elytral midpoint, extended basad by 1 or 2 faint punctures; internal subhumeral striae impressed nearly from elytral apex to elytral midpoint; dorsal striae all complete, strongly impressed, punctate at regular intervals; 5 th dorsal stria curving inward at basal terminus more sharply than other dorsal striae; sutural striae strongly impressed nearly from elytral apex to basal third, extended basad by a row of 2 or 3 punctures, may meet 5 th dorsal striae as a faint depression.
Mesosternum finely, densely punctate; anterior margin emarginate to receive posterior prosternal projection; marginal stria complete, deeply impressed, continuous with internal lateral metasternal stria; mesometasternal suture represented by a fine line; intercoxal disc of metasternum finely, densely punctate, a few dense punctures concentrated near metacoxal cavities; lateral metasternal stria straight, strongly impressed, nearly reaching outer margin of metacoxal cavity; posterior mesocoxal stria strongly divergent from lateral metasternal anterad but parallel posterad for most of its length, about as long as lateral metasternal stria but not reaching outer margin of metacoxal cavity; lateral disc coarsely, sparsely punctate throughout.
Intercoxal disc of 1 st abdominal ventrite finely, densely punctate throughout, bistriate on each side medial to metacoxal cavity; lateral disc coarsely, sparsely punctate anteriorly and coarsely, densely punctate posteriorly, bearing a single stria along outer margin; surface may occasionally bear some very faint microrugulosity.
Propygidium hexagonal, coarsely and very densely punctate; pygidium less coarsely and densely punctate than propygidium.
Outer margin of protibia bidentate in distal half. Denticles rounded, deflexed, not projecting much beyond tibial margin; outer margin of mesotibia tridentate, with 2 denticles inserted near apex and 3 rd inserted at about midpoint; outer margin of metatibia bidentate, both denticles inserted near tibial apex.
Parameres of aedeagus elongate, narrowed, tapering to an acute point, subequal in length to the basal piece ( Fig. 9H View Fig )
Comparison with Related Species. Carcinops torquatus is similar in morphology to C. rugulus and C. curtus . It can be distinguished from C. rugulus by the marked widening and sinuosity of the marginal stria of the pronotum behind the head and the absence of microrugulosity on the surface of the lateral disc of the first abdominal ventrite ( Fig. 5A View Figs ). Carcinops torquatus can be distinguished from C. curtus by the continuation of the head frontal stria beyond the anterior margin of the eye ( Fig. 4B View Figs ).
Geographic Distribution and Natural History. Carcinops torquatus is a Mexican species known from the tropical dry forest of southern Sonora and the much more southern states of Hidalgo and Veracruz. Most Sonoran specimens collected by APS were found in S. montanus , and specimens collected by H. Dybas in Hidalgo and Veracruz are labeled as having been taken from “pipe organ cactus.” However, APS collected a single female specimen from a necrotic Opuntia sp. ( Martin et al. 1998) cladode near Alamos, Sonora. This collection was made at the height of the dry season when necroses in Stenocereus spp. are scarce, so association with Opuntia may not be typical. Carcinops torquatus specimens have been absent from collections taken in Baja California Sur, Arizona, and southern California, indicating a likely more southern range than other species of cactophilic Carcinops in the Sonoran Desert.
Additional Material Examined. 14 specimens. MEXICO: Hidalgo: Tasquillo , 16.VIII.1941, in pipe organ cactus, H. Dybas ( FMNH, 10) . Veracruz: Rinconada , ca. 2,000 ft, 29.VI.1941, H. Dybas ( FMNH, 3) . USA: Texas: Brownsville , 22.VIII.1941, H. Dybas ( FMNH, 1) .
Derivation of Specific Epithet. This species is named for the collar-like aspect of the marginal stria of the pronotum behind the head, though it should be noted that C. torquatus shares this character with C. curtus ( Fig. 5A View Figs ).
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