Diastolinus coarctatus ( Mulsant and Rey, 1859 )

Hart, Charles J. & Ivie, Michael A., 2016, A Revision of the Genus Diastolinus Mulsant and Rey (Coleoptera: Tenebrionidae), The Coleopterists Bulletin 70 (3), pp. 485-540 : 485-540

Diastolinus coarctatus ( Mulsant and Rey, 1859)

( Figs. 36–40 , 103 )

Sellio coarctatus Mulsant and Rey 1859: 106, 1860: 170 (type locality: Hispaniola); Leng and Mutchler 1914: 461 (Hispaniola); Gebien 1938: 407 [444] (Hispaniola); Marcuzzi 1957: 129 (Hispaniola), 1962: 31 (in part, Hispaniola records only), 1984: 82 (in part, Hispaniola records only); Garrido 2004b: 119 (in part, Hispaniola records only); Perez 2008: 113 (Hispaniola); Peck 2011a: 33 (in part, Hispaniola records only), 2016: 160 (in part, Hispaniola records only).

Sellio coarctatum ; Blackwelder 1945: 525 (Hispaniola).

Diastolinus estebani Garrido 2004a: 42 (type locality: Hispaniola), 2007: 45 (Hispaniola); Perez 2008: 113 (Hispaniola). New synonymy.

Diastolinus estebanii ; Herrera-Uria et al. 2015: 95 (Hispaniola) (lapsus calami).

Sellio tibidens ; Perez 2008: 113 (Hispaniola).

Type Material. Types were not seen for D. coarctatus , though they are reported to be in the Chevrolat collection, and the type locality is recorded as Saint-Domingue. They were not found in the BMNH (M. Barclay, in litt.), nor in the Mulsant and Rey collection in Lyon (H. Labrique, in litt.). They are possibly in the Oberthur collection in MNHN. The Garrido type for D. estebani is housed in MNHC and photographed in Garrido (2004a).

Other Material Examined. See Appendix 1.

Diagnosis. Both males and females of this species can be distinguished from other Hispaniolan species by the combination of a robust, convex body, 8.8 mm long or longer, with costate elytra covered with golden setae almost equal to or longer than width of interstriae and the base of elytra subequal to the pronotal width. Additionally the scutellum is short, mostly hidden, and the width is more than two times the length. Male foretibiae are unarmed in this species.

Redescription. Male. Length 8.8–9.2 mm, width 3.9–4.2 mm. Body ( Fig. 36 ) black, except last 3 antennomeres reddish testaceous, last antenomere almost golden; somewhat shiny convex, oblong; covered in relatively long, yellow setae.

Head ( Fig. 36 ) with epistoma evenly convex; punctures greater than diameter of ommatidium, covering dorsal surface, evenly spaced, separated by less than 1 puncture diameter; setae 2X longer than than puncture diameter. Labrum densely punctate, punctures smaller than punctures on head, separated by less than 1 puncture diameter. Antenna weakly clavate. Dorsal portion of eye circular; ventral portion somewhat ovate. Gular horns short, not prominent.

Pronotum ( Fig. 37 ) widest at middle; apical margin slightly bisinuate; apical corners rounded, lateral margin widened from apex in anterior 1/2, then sides rounded to base; base slightly wider than width across humeri; basal margin bisinuate; dorsal surface broadly, evenly convex; all margins narrowly beaded, except obsolete at middle of anterior margin, bead may be obscured somewhat by setae; heavily punctate, puncture diameter equal to punctures on head, closely spaced, often less than or equal to puncture diameter on pronotal disc; yellow setae on pronotal disc, longer laterally, typically at least 2X length of puncture diameter. Hypomeron rugulose, punctate, setose. Prosternal process lanceolate, long, almost reaching mesoventrite, punctate, setose.

Scutellum ( Fig. 37 ) short, mostly hidden, crescentshaped if visible. Elytra constricted in anterior 1/3. Elytron gradually broadening from base to widest point, opposite abdominal ventrite 1, then evenly arcuate to apices; striae heavily impressed; strial punctures deep, sometimes confluent; intervals convex, punctation minute. Stria 7 ending in lateral stria slightly posterior to humeral angle.

Mesoventrite punctate, shiny. Metaventrite short, punctate on anterior border behind mesocoxae.

Leg surfaces densely setose and finely punctate. Femora expanded. Protibia narrow, expanding gradually distally; dorsolateral margin somewhat arcuate; posteroventral surface with stout spines in apical 1/3; apex obliquely truncate, ringed by stout spines. Pro- and mesotarsi with tarsomeres 1–3 expanded, ventrally with golden, densely setose pads, tarsomere 2 widest, more than 1.5X width of tarsomere 4. Metatarsus narrow, about 3/4 as long as metatibia, without setose pads; 1 st tarsomere more than 1.5X length of 2 nd.

Abdomal ventrites ( Fig. 38 ) with large, scattered punctures; ventrites 1–2 slightly concave medially, concavity not extending onto intercoxal process; anterior border of ventrite 1, just behind hind coxae, with row of heavy punctures extending onto intercoxal process; ventrites 2 and 3 laterally with row of heavy punctures on anterior edge, indistinct on medial concavity; ventrite 5 flattened medially, heavily punctate, posterior margin evenly rounded. Aedeagus ( Figs. 39, 40 ) with basal piece and parameres strongly arched, equal to 1/2 elytral length; parameres widest basally, narrowed apically; then expanding to widest point, just before apex, then rounded broadly at apex; parameres with slightly sinuate lateral margin, without upturned tips in lateral view.

Female. Length 8.8–9.5 mm, width 4.0– 4.4 mm. Similar to male except pro- and mesotarsi not expanded. Abdominal ventrites 1–3 slightly convex; ventrite 5 slightly convex.

Biology. Specimens have been taken in coastal thorn scrub and tropical dry forest from elevations of 30–150 m above sea level.

Distribution. Hispaniola. The type locality is simply Saint-Domingue. All specimens examined are from Pedernales Province, Dominican Republic. This species seems to be restricted to the southern paleo-island ( Fig. 103 ).

Diastolinus coarctatus (Mulsant and Rey)

DOMIN. REP: Pedernales Prov. 10 km N. Cabo Rojo; 19AUG1988; thorn scrub, 30–45m; M.A. Ivie, T.K. Phillips, & K.A. Johnson (3 WIBF) . DOMIN. REP: Pedernales Prov. 14 km N. Cabo Rojo; 19AUG1988; thorn scrub- trop.dry forest, 150 m; M.A. Ivie, T.K. Phillips, & K.A. Johnson (1 WIBF). REP.DOM. Pedernales Prov. Cabo Rojo; XII-28-1986; Doyen; coastal thorn scrub association (2 WIBF) .

Figures

Figs. 36–40. Diastolinus coarctatus. 36) Dorsal habitus; 37) Pronotum; 38) Abdominal ventrites; 39) Aedeagus, dorsal view; 40) Aedeagus, lateral view.

Fig. 103. Map of the distributions of Diastolinus species on Hispaniola.