Diastolinus maritimus ( Champion, 1896 )

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 maritimus ( Champion, 1896)

( Figs. 92–97 , 106 )

Ctesicles maritimus Champion 1896: 8 (type locality: Grenada and Mustique); Leng and Mutchler 1914: 461 ( Grenada, Mustique); Gebien 1938: 401 [438] (Lesser Antilles); Marcuzzi 1957: 129, 1984: 79 ( Grenada, Mustique).

Ctesicles maritima ; Blackwelder 1945: 524 ( Grenada, Mustique); Woodruff et al. 1999: 44 ( Grenada, Mustique); Peck 2016: 159 ( Grenada, Mustique).

Type Material. Champion did not designate a type. Among the syntypes, the first of these listed is hereby designated the lectoype, the remainders as paralectotypes, and they are so labeled: Telescope Est.; (Windward side); Grenada, W.I.; H.H. Smith.; 70/ W. Indies.; 96-98/ Ctesicles ; maritimus Ch. ; ♂ / Syntype / WIBF 035661/ LECTOTYPE; Ctesicles ; maritimus ; Champion 1896 (1 BMNH). Lake Antoine Est.; (Windward side); Grenada, W.I.; H.H. Smith.; 32/ W. Indies.; 96-98/ Ctesicles ; maritimus Ch. ♂ / WIBF 035660/ PARALECTOTYPE; Ctesicles ; maritimus ; Champion 1896 (1 BMNH). Telescope Est.; (Windward side); Grenada, W.I.; H.H. Smith.; 70/ W. Indies.; 96-98/ Ctesicles ; maritimus Ch. / PARALECTOTYPE; Ctesicles ; maritimus ; Champion 1896 (2 BMNH, WIBF 035662 - 035663). Telescope Est.; (Windward side); Grenada, W.I.; H.H. Smith.; 66/ W. Indies.; 96-98/ Ctesicles ; maritimus Ch. / specimens from this loc.; presented to Kaszab 29.1.58; Zool.Mus.Hung. Budapest/ PARALECTOTYPE; Ctesicles ; maritimus ; Champion 1896 (2 BMNH, WIBF 035664 - 035665). Mustique I.; Grenadines. W.I.; H.H. Smith./ W. Indies.; 96-98/ Ctesicles ; maritimus Ch. ; ♀ / Syntype / WIBF 035666/ PARALECTOTYPE; Ctesicles ; maritimus ; Champion 1896 (1 BMNH). Mustique I.; Grenadines. W.I.; H.H. Smith./ W. Indies.; 96-98/ Ctesicles ; maritimus Ch. / WIBF 035667/ PARALECTOTYPE; Ctesicles ; maritimus ; Champion 1896 (1 BMNH).

Diagnosis. This species can be distinguished by its small size (6.0 mm or less), large punctures covering the entire body surface, upper surface covered with yellow pubescence, deeply impressed strial punctation with punctures commonly interrupting and overflowing onto the interstriae, dull, broad elytral intervals, and male aedeagus with parameres that have a slightly emarginate apical margin.

Redescription. Male. Length 4.8–5.6 mm, width 2.0– 2.3 mm. Body ( Fig. 92 ) black, except antennae pitchy red, last 3–4 antennomeres testaceous, sometimes tarsi reddish; upper surface dull, venter weakly shiny; ovate-oblong; moderately convex; scattered, yellow setae covering body.

Head ( Fig. 93 ) with epistoma flattened; punctures greater than diameter of ommatidium, covering dorsal surface, spaced less than 1X puncture diameter; setae 1.5–2.0X length of punctures. Labrum densely punctate, punctation smaller than that on frons. Antenna clavate. Dorsal and ventral portions of eye somwhate oblong-ovate, roughly equal in size and shape. Gular horns short, not prominent.

Pronotum ( Fig. 93 ) widest just anterior of middle, anterior width slightly narrower than basal width; apical margin evenly, broadly emarginate; apical corners rounded, lateral margin widened from apex to just anterior of middle, then sides gradually narrowed to base; basal width narrower than width across humeri; basal margin bisinuate; dorsal surface broadly, evenly convex; all margins narrowly beaded, except obsolete at middle of anterior margin and middle of posterior margin; heavily punctate, puncture diameter equal to that of punctures on head, spaced much less than 1X puncture diameter on pronotal disc, almost confluent; distinct yellow, recumbent setae originating from punctures. Hypomeron covered in deep punctures. Prosternal process short, bluntly rounded, punctate, with scattered yellowish, semi-erect setae.

Scutellum ( Fig. 93 ) small, triangular, about 2X wider than long. Elytron ( Figs. 93, 94 ) broadening from base to widest point opposite abdominal ventrite 1, then evenly arcuate to apices; striae impressed; strial punctures deep, often confluent, interrupting interstrial line; intervals broadly convex, punctation minute. Stria 7 ending in lateral stria at humeral angle.

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

Leg ( Fig. 94 ) surfaces setose and heavily punctate. Profemora somewhat expanded and clavate. Protibia narrow, expanding gradually distally; dorsolateral margin nearly straight; posteroventral surface with stout spines in apical 2/3; apex obliquely truncate, ringed by stout spines. Protarsus with tarsomeres 1–3 expanded, ventrally with golden, densely setose pads, tarsomere 2 widest, 1.5X width of tarsomere 4. Mesotarsus with tarsomeres 1–3 weakly expanded, ventrally with densely setose pads. Metatarsus narrow, about 3/4 length of metatibia, without setose pads; 1 st tarsomere more than 2X length of 2 nd.

Abdominal ventrites ( Fig. 95 ) heavily punctate; covered in semi-erect, yellowish setae; ventrites 1–2 flattened medially; anterior border of ventrite 1, just behind hind coxae, with row of heavy confluent punctures; ventrite 5 flattened medially, posterior margin evenly rounded. Aedeagus ( Figs. 96, 97 ) with basal piece and parameres arched, about 1/2 elytral length; parameres parallel in basal 1/2, then slightly widened and gently rounded to apex, apical margin slightly emarginate; parameres with weakly sinuate lateral margin, without upturned tips in lateral view.

Female. Length 5.2–6.0 mm, width 2.1– 2.6 mm. Similar to male except body typically larger, more ovate and robust than male. Pro- and mesotarsi not expanded. Abdominal ventrites 1-3 slightly convex medially; ventrite 5 slightly convex.

Biology. Unknown.

Distribution. Mustique, Grenada ( Fig. 106 ).

Figures

Figs. 92–97. Diastolinus maritimus. Lectotype: 92) Dorsal habitus; 93) Pronotum. Paralectotype: 94) Lateral habitus; 95) Abdominal ventrites; 96) Aedeagus, dorsal view; 97) Aedeagus, lateral view.

Fig. 106. Map of the distributions of Diastolinus species in the Lesser Antilles.