Diastolinus desecheo Hart and Ivie, 2016

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 desecheo Hart and Ivie , new species

( Figs. 41–45 , 98 , 104 )

Type Material. HOLOTYPE: Male. PUERTO RICO; Desecheo Is. ; 28-Mar.-61; J. R. Gorham. / OSUC 622882 ( OSUC) . PARATYPES (9 specimens): 1 male and 2 females with same label data as holotype, ( OSUC 622881 , 622883 , 622885 ). P.R.: Desecheo Is.; 27-29-V-1965; Heatwole, Levins; & McKenzie. (5 males and 1 female, WIBF 035176 - 035178, 035180 - 035182) .

Other Material Examined. See Appendix 1.

Etymology. Named after the type locality, Desecheo Island.

Diagnosis. This species can be distinguished from most other Puerto Rico species by the large, elongate oval body and the anterior margin of the pronotal bead complete. It is similar in overall appearance to D. victori , but can be distinguished by the combination of comparatively shallow elytral punctation, the punctation on abdominal ventrites 2 and 3 shallow, and the male genitalia differ in form.

Description. Male. Length 9.5–10.5 mm, width 4.2–4.5 mm. Body ( Fig. 41 ) black, except antennomeres 1–8 reddish black, last 3 antennomeres testaceous; upper surface dull; elongate; widest on pronotum; moderately convex; scattered light colored setae, typically short.

Head ( Fig. 41 ) widely transverse, somewhat flattened; punctures sub-equal in diameter to ommatidia covering dorsal surface, evenly spaced, separated by more than 1X puncture diameter posteriorly, spaced more closely anteriorly; setae sparse and short. Labrum densely punctate, punctures equal in size to punctures on head, closely spaced, shallow. Antenna weakly clavate. Dorsal portion of eye perfectly rounded; ventral portion of eye ovate. Gular horns long, robust and very prominent (compare to Fig. 76 ).

Pronotum ( Fig. 42 ) widened posteriorly; apical margin evenly, broadly emarginate; apical corners rounded, lateral margin widened from apex in anterior 1/2, then sides nearly parallel to base; basal width equal to humeri; basal margin bisinuate; dorsal surface broadly, evenly convex; all margins narrowly beaded ( Fig. 98 ); punctate, puncture diameter sub-equal to punctures on head, spaced 2-3X diameters of puncture apart on pronotal disc; setae absent on disc, minute setae visible occasionally laterally. Hypomeron rugulose. Prosternal process tongue-like, shallowly punctate, with yellowish semi-erect setae.

Scutellum ( Fig. 42 ) triangular, about 1.5X wider than long. Elytra constricted in anterior 1/3. Elytron gradually broadening from base to widest point opposite abdominal ventrite 1, then evenly arcuate to apices; striae shallowly impressed; strial small, shallow, not confluent; intervals broadly convex, punctation minute;. Seventh stria ending in lateral stria posterior to humeral angle.

Mesoventrite somewhat rugulose. Metaventrite very short, punctate on anterior border behind mesocoxae.

Leg surfaces setose and finely punctate. Femora expanded. Protibia narrow basally, then gradually widened; posteroventral surface with stout spines in apical one-third; apex obliquely truncate, ringed by stout spines. Protarsus with tarsomeres 1-3 expanded, ventrally with golden, densely setose pads, tarsomere 2 widest, more than 2X width of tarsomere 4. Mesotarsus somewhat expanded, ventrally with golden, densely setose pads. Metatarsus narrow, about 3/4 as long as metatibia, without setose pads; first tarsomere 2.5X length of second.

Abdominal ventrites ( Fig. 43 ) finely punctate, with white or yellow setae covering surface; ventrites 1–2 slightly concave medially, concavity extending onto intercoxal process; anterior border of ventrite 1, just behind hind coxae, with row of punctures barely extending onto intercoxal process, longitudinally rugulose areas posterior of punctures; ventrite 2–3 with row of shallow punctures on anterior edge, absent medially, longitudinally rugulose areas posterior of punctures; ventrite 5 flattened medially, posterior margin evenly rounded. Aedeagus ( Figs. 44, 45 ) with basal piece and parameres strongly arched, about equal to 4/7 elytral length; parameres nearly parallel basally, then slightly expanding, then subparallel until broadly rounded and converging at apex; parameres with slightly sinuate lateral margin, with upturned tips in lateral view.

Female. Length 10.0– 10.6 mm, width 4.5– 4.6 mm. Similar to male except pro- and mesotarsi not expanded. Abdominal ventrites 1–3 slightly convex medially; ventrite 5 slightly convex.

Biology. Unknown.

Distribution. Desecheo Island* (PR, OSUC, WIBF).

Diastolinus desecheo Hart and Ivie

P.R.: Desecheo Is.; 27-29-V-1965; Heatwole, Levins; & McKenzie/ WIBF 035179 (1 WIBF, specimen damaged) .

Figures

Figs. 41–45. Diastolinus desecheo, paratype. 41) Dorsal habitus; 42) Pronotum; 43) Abdominal ventrites; 44) Aedeagus, dorsal view; 45) Aedeagus, lateral view.

Figs. 98–101. Diastolinus species. 98) D. desecheo, pronotal bead; D. clavatus: 99) Pronotal bead; 100) Aedeagus - a) Ventral view, b) Lateral view; 101) Ovipositor - a) Dorsal view, b) Ventral view.

Fig. 104. Map of the distributions of the “sellio” species-group of Diastolinus species on Puerto Rico and Virgin Islands. Symbols on Puerto Rico represent collecting localities, and symbols on the Virgin Islands represent island distributions, not all collection events.

Figs. 73–79. Diastolinus victori. 73) Paratype, dorsal habitus; 74) Paratype, labels; 75) Pronotum; 76) Gular horn; 77) Abdominal ventrites; 78) Aedeagus, dorsal view; 79) Aedeagus, lateral view.