Xerolinus Ivie and Hart, 2016

Ivie, Michael A. & Hart, Charles J., 2016, Redefinition ofDiastolinusMulsant and Rey, with a Review of West Indian Blapstinoid Genera (Coleoptera: Tenebrionidae: Opatrini), The Coleopterists Bulletin 70 (3), pp. 447-481 : 447-481

Xerolinus Ivie and Hart , new genus

( Figs. 37–42 , 51 , 53 )

Type Species. Diastolinus sallei Mulsant and Rey , gender masculine.

Diagnosis. This group of flightless blapstinoid species are characterized by the anterior fusion of the seventh and eighth striae that do not reach the base of the elytron ( Fig. 38 ); a smooth-bottomed, delimited groove on ventrite I immediately bordering the metacoxa ( Fig. 41 ) (one exception); the aedeagus with the basal piece strongly arched and the parameres weakly sinuate in lateral view, the parameres at least slightly widened from the base to midpoint, then obliquely tapered to the rounded tip ( Figs. 39 ). Xerolinus waterhousei is an exception, as it has a line of punctures behind the metacoxa, but has the Xerolinus type of striae and aedeagus. This large and diverse group requires further study, several undescribed species are known.

Description. Length: 4.5–11.0 mm. Body oval to elongate oval ( Fig. 37 ), convex above; black except apical antenomeres, palps, setae, and tarsal pads variable, often reddish to golden or whitish. Head transverse; variously punctate; epistoma margin emarginate; labrum visible, apically bearing 2 tufts of golden setae ( Fig. 40 ) [must be clean to see this]; antennae with 11 antennomeres, weakly clavate ( Fig. 37 ); eyes small, divided by genal canthus, lobes subequal or lower somewhat smaller ( Figs. 37, 40 ); gula with anterolateral angles weakly to moderately produced ( Fig. 40 ). Pronotum matte, disc usually finely punctate; usually widest at base, occasionally widest anterior to base; anterior margin emarginate; posterior margin bisinuate, width at base subequal to humeral width; margins beaded ( Fig. 37 ); hypomeron variably punctate to rugose; prosternal process acute, tip weakly displaced ventrally ( Fig. 40 ). Scutellum variable, typically wider than long, triangular to rounded behind. Elytra fused together, locked to metathorax at epimeron; humeral angles narrowed; striae variable, from nearly totally effaced to deeply impressed and strongly punctate; striae 6 and 9 approaching at base, keeping striae 7 and 8 from reaching base ( Fig. 38 ), 7 and 8 fused or approaching, not reaching base of elytron, not deflected towards lateral margin ( Fig. 38 ). Mesoventrite short, deeply impressed to receive prosternal process ( Fig. 40 ). Metathoracic wings extremely reduced or absent. Metaventrite short, equal to or less than 2/3, usually less than 1/2 length of mesocoxa; variably punctate. Legs variably punctate and setose, femora clavate ( Fig. 40 ); femora unarmed; tibiae weakly expanded from base to apex, usually unarmed, occasionally with weak tooth on inner margin; males with protarsus and sometimes mesotarsus with tarsomeres 1–3 expanded, densely setose beneath ( Fig. 40 ). Abdominal ventrites variably punctate, from smooth and shining to rugose; ventrites 1–3 flattened or concave medially in male ( Fig. 41 ), weakly convex in female; ventrite 1 usually with distinct, smoothbottomed grove adjacent to hind margin of metacoxa ( Fig. 41 ), rarely with row of large punctures in this position. Aedeagus strongly curved in lateral view ( Fig. 42 ), parameres weakly sinuate in lateral view; in dorsal view, parameres weakly broadened from base to midpoint, then tapered to a narrowly rounded apex ( Fig. 39 ).

Distribution. The 29 described species of recognized Xerolinus species occur from South Florida through the Lucayan Archipleago and Greater Antilles ( Fig. 53 ), with one species reaching the British Virgin Islands. For the most part, they are single island or bank endemics. The center for the described members of the genus is the Cuban archipelago, with 19 described species, but the largely unstudied Lucayan Archipelago will almost certainly exceed that. Many species remain undescribed, including species from the Bahamas, Jamaica, Puerto Rico, and Great Camanoe, and many more islands remain unsampled.

Etymology. The prefix Xeros, from the Greek ξηρóς, meaning dry or arid, added to the suffix - linus from Diastolinus , referring to the xeric habitat characteristic of these beetles.

Figures

Figs. 37–42. Xerolinus sallei: 37) Dorsal habitus; 38) Humeral angle; 39) Aedeagus, dorsal view; 40) Head and thorax, ventral view; 41) Abdominal ventrites; 42) Aedeagus, lateral view.

Figs. 50–52. Humeral striae (indicated by white lines) of West Indian blapstinoid genera. 50) Blapstinus haitensis; 51) Xerolinus sallei. 52) Diastolinus clathratus.

Fig. 53. Distribution of the West Indian and south Caribbean blapstinoids.