Tomarus adoceteus Ratcliffe & Cave 2010

Tomarus adoceteus Ratcliffe & Cave, 2010

(Figs. 1H, 16A, 19A, 27A; 41)

Tomarus adoceteus Ratcliffe & Cave, 2010: 7. Original combination.

Male holotype (BMNH) “Roy Soc-CIG Expdn. / Little Cayman, BWI / Pirates’ Point / House light / 30.7.1975. R.R.Askew // BM 1981 / 342 // TOMARUS / ADOCETEUS / RATCLIFFE & CAVE / HOLOTYPE ” Female paratype (BMNH) “GRAND CAYMAN IS. B.W.I. / Georgetown / 16 sept 1973 / E. J. Gerberg // At black light // Ratcliffe & Cave / db Dynastine / West Indies // TOMARUS / ADOCETEUS / RATCLIFFE & CAVE / PARATYPE. Female paratype (BMNH) “WEST INDIES: Cayman Is. / Grand Cayman / VI-1992 coll. P. Fitzgerald / blacklight trap // Ratcliffe & Cave / db Dynastine / West Indies // TOMARUS / ADOCETEUS / RATCLIFFE & CAVE / PARATYPE. Female paratype (BCRC) “Roy Soc-CIG Expdn. / Little Cayman / Pirates’ Point / 9.viii.1975 // TOMARUS / ADOCETEUS / RATCLIFFE & CAVE / PARATYPE ”. Type locality: Pirates’ Point, Little Cayman Island.

Description. Habitus as in Fig. 27A. Length 20.0– 22.5 mm; humeral width 10.3–12.4 mm. Color dark reddish brown to black. Head: Frons and clypeus coarsely and densely rugose. Frontoclypeal region with 2 transverse, low tubercles separated by about 7 tubercle diameters. Clypeus narrowed towards apex, base 3 times as wide as apex (Fig. 1H). Clypeal teeth small, transverse, separated by a tooth diameter. Mandible with 2 apical teeth and a lateral, slightly rounded tooth. Mentum abruptly constricted at apical 3rd. Galea of maxilla with teeth 5 and 6 vestigial. Interocular distance 3.5 times an eye width. Pronotum: Surface with small punctures; denser and deeper on anterior and lateral angles. Apical tubercle small, rounded, not visible in lateral view. Subapical fovea shallow, elongate, narrow (1/3 the interocular distance); equal in both sexes, surface rugopunctate. Scutellum: With deep, large punctures forming 2 lines parallel to margins. Elytra: Punctures on first interval as large as those on other intervals; sutural stria complete. Inner surface of apex with rounded, large tubercles forming 13–14 parallel lines. Abdomen: Apex of tergite IV with a triangular wide area with small, irregular tubercles forming 12–14 diagonal, nearly parallel lines. Pygidium with dense rugosity on basal 3rd; apex rounded. Venter: Apex of prosternal process flat, transversely oval to rounded. Metasternum with minute setae on anterior angles. Legs: Protibia tridentate, without basal denticle. Apex of metatibia crenulate, with 10–11 spinules. Male genitalia: Phallobase 1.2 times longer than parameres. Parameres with 2 dorsal teeth on each side; basal tooth acute, longer than apical tooth that is inconspicuous (Figs. 16A, 19A). Internal sac with copulatory lamella and short lamellar spiny belt; with a complex of 7 spine-like, accessory lamellae, with dense granules at base.

Diagnosis. Tomarus adoceteus is differentiated by the following character combination: frontoclypeal tubercles transverse and low (Fig. 1H); galea of maxilla with teeth 5 and 6 vestigial (as in T. subtropicus, Fig. 4I); pronotal surface with small punctures; pronotal tubercle not visible in lateral view; pronotal fovea shallow and narrow (1/3 as wide as interocular distance) (Fig. 27A); protibia tridentate, without an additional basal denticle; apex of metatibia with 10–11 spinules; parameres with 2 dorsal teeth on each side, main teeth long, widely separate from secondary; apex of parameres slender (Figs. 16A, 19A).

Taxonomic remarks. Tomarus adoceteus was described originally by Ratcliffe & Cave (2010) in the genus Tomarus, but Morón & Grossi (2015) placed it in Ligyrus, while their most similar species were remained in Tomarus. The phylogenetic analysis evidences that this species does not have a close relationship with the members of Ligyrus, so it is maintained in its original combination.

Distribution. Bahamas and Cayman Islands (Ratcliffe & Cave 2015). A single male specimen from Yucatán (Mexico) was examined but more evidence is necessary to confirm that the species occurs in that country.

Locality records (Fig. 41). 7 specimens examined from BCRC, BMNH, and IEXA. Some records from Ratcliffe & Cave (2015). BAHAMAS (6). Bimini (4): Allen Cay; North Bimini; South Bimini. CAYMAN ISLANDS (7). Grand Cayman (3): Georgetown. Little Cayman (4): Pirate’s Point. MEXICO (1). Yucatán (1): Reserva Estatal El Palmar.

Natural history. Little is known about T. adoceteus. Specimens have been found between June and September using blacklights.