Deretaphrus iridescens Blackburn, 1903

Lord, Nathan P. & McHugh, Joseph V., 2013, A Taxonomic Revision of the Genus Deretaphrus Newman, 1842 (Coleoptera: Cucujoidea: Bothrideridae), The Coleopterists Bulletin (mo 12) 67, pp. 1-107 : 37-38

Deretaphrus iridescens Blackburn, 1903 , new status

( Figs. 71 , 110–111 , 154 , 177 , 218–219 )

Deretaphrus iridescens Blackburn, 1903: 126 . Carter and Zeck 1937: 200–201.

Diagnosis. This species can be readily distinguished from congeners by the strongly flattened dorsal surface of the pronotal disc, the disc with a weakly interrupted, shallow median longitudinal canal, the nearly smooth elytral interstitial intervals, a simple abdominal ventrite V, and the shape of the submentum. This species is most similar to D. piceus and D. gracilis . Deretaphrus iridescens can be distinguished from D. piceus by the simple abdominal ventrite V, the larger and denser punctures on the pronotal disc, the less foveate anterior portion of the pronotal median longitudinal canal, and the less dense setation of the antennal club. It can be distinguished from D. gracilis by the more weakly developed anterior and posterior portions of the median longitudinal canal, the pronotum being more or less flat medially and less distinctly deflexed laterally, and a distribution restricted to eastern Australia.

Redescription. Length 6.3–9.1 mm. Width 1.5–2.5 mm. Body elongate, parallel, dark brown to black; dorsal surface glabrous, matte to weakly shiny; ventral surface moderately shiny, glabrous except for minute setae that arise from punctures. Head: In dorsal view, slightly narrowed anteriorly; without laterally expanded supra-ocular ridges; eyes visible from above; punctures small and dense except sparse along posterior margin. Frontoclypeal suture not distinct, arcuate anteromedially. Anterior margin of clypeus broadly arcuate. Submentum shape as in Fig. 51 ; distinctly separated from subgenal braces, with paired setose pits; anterior margin moderately expanded anteroventrally over oral cavity; a portion of the mentum visible. Antennal groove well-developed, impunctate. Antenna densely setose; segment 1 with few setae on ventral surface; segments 2–4 with short setae; segments 5–11 with long, golden setae that extend beyond distal margin of antennal segment from which they arise. Antennal club segments with multiple transverse rows of setae. Antennal club subsymmetrical. Dorsal surface (external face) of mandible with median setose groove. Thorax ( Fig. 71 ): Pronotum elongate, pronotum widest near anterior ¼; dorsal surface flattened; anterior margin arcuate, slightly wider than head; anterior angles rounded; base narrower than elytral bases; posterior margin weakly sinuate; posterior angles with small denticle; lateral margin with incomplete carina, forming a distinct raised border in dorsal view. Pronotal disc with small, sparse punctures. Pronotal median longitudinal canal present, weakly developed, interrupted anteriorly; anterior portion a weak slit, surrounding area slightly depressed; raised interruption of the canal impunctate; posterior canal narrow, weakly impressed, gradually tapering posteriorly, open at the base, internal lateral margins of canal grooved. Hypomeron minutely punctate; lateral walls nearly vertical. Prosternum flat medially, strongly deflexed at lateral margin. Tergosternal suture slightly sinuate. Elytra ( Figs. 110–111 ): Elytron flattened dorsally; interstitial intervals 3, 5, and 7 feebly raised near apex; interval 5 meets or nearly meets interval 9 near apex. Basal elytral margin with intervals 3 and 5 each ending in a knob-like protuberance; finger-like callosity on the elytral shoulder weakly developed. Legs: Setation sparse; inner face of tibia with fringe of long, dense setae. Tarsus densely setose with long setae that extend beyond the segment from which they arise. Abdomen: Ventrite V simple. Aedeagus: Phallobase as in Fig. 154 . Tegmen consisting of paired, elongate, anteriorlyprojecting subtriangular plates at middle; plates narrowly touching medially. Basal piece with long anterolateral struts; struts recurved anteriorly. Parameres rounded, broadly fused to one another near base, collectively slightly transverse and articulated to phallobase; each paramere with a single elongate-oval patch, extending from near base to apex, apical portion slightly narrowed, patch lighter in color than remainder of paramere; paramere sparsely setose with short setae at apical margin; dorsal surface of paramere lacking process; Penis similar to Fig. 167 ; elongate, slender, variously curved; apex narrowed and pointed; base slightly expanded, bearing long, slender, paired anterior struts. Penis slightly lighter in color near base.

Variation. The size and coloration are variable within the species. In some, the anterior portion of the pronotal median longitudinal depression is more well-developed. In a few specimens, the posterior portion of the pronotal median longitudinal depression is slightly more impressed, in others the canal gradually narrows towards the base.

Distribution. Australia: New South Wales, South Australia, and Victoria ( Fig. 177 ).

Biology. Not known.

Taxonomic Notes. D. iridescens Blackburn was synonymized under D. gracilis Blackburn by Carter and Zeck (1937). After examination of material and type specimens, it is clear that D. iridescens is a distinct species and is thus here removed from synonymy.

Remarks. Blackburn (1903) did not mention the number of specimens examined. A specimen from Blackburn’ s collection in the BMNH bears handwriting on the card-mount and labels consistent with Blackburn syntypes, although it lacked locality information. We assume this specimen is a syntype. In order to stabilize this name, a lectotype is here designated from the syntype series of D. iridescens .

Type Locality. Adelaide District , South Australia .

Type Material Examined. L E C T O T Y P E ( Figs. 218–219 ) (♀, BMNH, point-mounted) label data: “T. 7201 [in Blackburn’ s hand at base of card-mount; “T.” is written in black ink, “7201” is written in red ink, is written in red ink with a black strikethrough] // Type H.T.” [round label with orange border] // Australia. [red underline] Blackburn Coll. B.M.1910-236. // Deretaphrus iridescens, Blackb [in Blackburn’ s hand]”. [ BMNH 101 NL, examined]. This type was removed from the original card-mount and point-mounted. The original card-mount, abdomen (glued to a card, bearing a ♀ symbol)], and genitalia (in glycerin in genitalia vial) are pinned beneath the specimen .

Additional Material Examined (30). AUSTRALIA: NEW SOUTH WALES: Baan Baa ( BMNH 31 NL); Bogan River ( ANIC 29 NL, ANIC 74 NL, ANIC 184 NL, ANIC 186–187 NL, ANIC

191 NL, ANIC 194 NL, ANIC 285 NL, ANIC 289 NL); Caldwell ( MVMA 61 NL); Dubbo ( ANIC 190 NL, ANIC 192 NL); Mullaley ( ANIC 188 NL); Wagga Wagga ( BPBM 16–19 NL, MAMU 44 NL); no locality ( MAMU 30 NL). SOUTH AUSTRALIA: Lucindale ( SAMA 8–9 NL); Wirrabara ( SAMA 237 NL). VICTORIA: Black Rock ( MVMA 62 NL); Mildura ( MVMA 90 NL); Sea Lake ( MVMA 60 NL). STATE UNKNOWN: no locality ( AMSA 54 NL, HNHM 7 NL, MVMA 63 NL, MVMA 91 NL).

Figures

Figs. 66–74. Deretaphrus species, pronotum. 66) D. gracilis; 67) D. hoplites; 68) D. ignarus; 69) D. incultus;

Figs. 106–111. Deretaphrus species, elytra, dorsal and lateral views. 106–107) D. incultus; 108–109) D. interruptus;

Figs. 149–157. Deretaphrus species, phallobase. 149) D. gracilis; 150) D. hoplites; 151) D. ignarus; 152) D. incultus;

Figs. 177–178. Distribution of Deretaphrus species. 177) D. aequaliceps, D. erichsoni, D. iridescens, and D. ocularis;

Figs. 210–218. Primary type specimens and specimen labels of Deretaphrus species. 210–211) D. ignarus, lectotype, BMNH; 212–213) D. pascoei, lectotype, ANIC; 214–215) D. incultus, lectotype, AMSA; 216–217) D. interruptus, lectotype, MNHUB; 218) D. iridescens, lectotype, BMNH.

Figs. 219–227. Primary type specimens and specimen labels of Deretaphrus species. 219) D. iridescens, lectotype labels; 220–221) D. lateropunctatus, holotype, BMNH; 222–223) D. ocularis, holotype, SAMA; 224–225) D. oregonensis, lectotype, MCZ; 226–227) D. parviceps, lectotype, SAMA.

Figs. 48–53. Deretaphrus species, head capsule, ventral view, showing setae and shape of submentum. 48) D. ignarus;

Figs. 165–172. Deretaphrus species, penis (left: dorsal view; right: lateral view; phallobase, to scale with penis). 165) D. boliviensis; 166) D. bucculentus; 167) D. gracilis; 168) D. hoplites; 169) D. ignarus; 170) D. oregonensis; 171) D. parviceps; 172) D. puncticollis.