Omorgus (Omorgus) rimulosus ( Haaf, 1957 ), 2023

Strümpher, Werner P. & Kalawate, Aparna S., 2023, Omorgus (Omorgus) khandesh (Coleoptera: Scarabaeoidea: Trogidae), a new species from India, along with an annotated catalogue of the Oriental and Palearctic species of the subgenus Omorgus Erichson, 1847, Zootaxa 5231 (5), pp. 501-522 : 507

Omorgus (Omorgus) rimulosus ( Haaf, 1957)

( Figs. 7–10 , 14–16 )

Trox rimulosus Haaf, 1957: 693 (original description).

Trox (Omorgus) rimulosus: Scholtz, 1982: 13 (catalogue).

Omorgus (Afromorgus) rimulosus: Zidek, 2013: 16 , 21 (checklist); Zidek 2017: 107, 113 (checklist); Kalawate & Patole 2018: 11990 (country records).

Type locality. “Coromandel” [= southeastern coast of the Indian subcontinent], Tamil Nadu State, India .

Type material examined. India, Tamil Nadu province. Holotype ♁ ( NHMB, specimen cleaned, aedeagus extracted) ( Figs. 7–9 ), “Coromandel [rectangle, white cardstock] || HOLOTYPUS | Trox | rimulosus sp.n. | det. Dr.E. Haaf 1957 [rectangle, white cardstock]”.

Redescription of holotype (♁). Size. Length: 12.8 mm. Width: 7.2 mm.

Body shape. Elongate oval, elytral margins subparallel, elytral profile convex, attaining maximum height behind the middle, strongly declivous posteriorly.

Colour ( Figs. 7–9 ). Black, surface of head, pronotum, legs, elytral margins and tubercles, and parts on the ventral side with light brown tomentose coating. Body setae mostly brown, to rust-brown.

Head ( Figs. 7–9 ). As in O. (O.) khandesh .

Pronotum ( Figs. 7–9 ). As in O. (O.) khandesh , except tubercles and ridges on pronotum are higher and more pronounced. Lateral margin strongly emarginate in middle anterior to greatest width, there angle obtuse, margin extended laterally, with strong emargination of margin posteriad of greatest width.

Scutellum ( Fig. 7 ). Hastate, as wide as long, surface finely sculpted, mediobasally depressed, surface finely sculpted, margins thickly tomentose.

Elytra ( Figs. 7–8 ). Relative dimensions, margins, and profile as in O. (O.) khandesh . Humeral calli, and sutural margin as in in O. (O.) khandesh . Humeral calli, and sutural margin as in in O. (O.) khandesh . Elytral costae distinct, even numbered costae more prominent than odd-numbered. Apical callosity present on fourth costal interval at top of elytral declivity. Even-numbered costae with raised, large, oval to round tubercles (especially on intervals 2, 4 and 6), these tubercles widely spaced along elytral length, each with posterior tomentosity and short setae, small nitid areas at front or sides of each tubercle; tubercles on costa 8 small, regularly spaced along elytral length, tubercles slightly larger and higher than tubercles on costae 7. Odd-numbered costae marked by small round to oval tubercles and irregularly spaced nitid areas; tubercles fairly evenly spaced along elytral length, size variable, each almost completely tomentose; nitid areas slightly raised, irregular in shape. Intercostae as in O. (O.) khandesh . Elytral surface shiny, mostly smooth, without undulations and grooves; elytral profile convex, attaining maximum height approximately in the middle.

Metathoracic wings. Complete.

Legs ( Figs. 3–5 ). As in O. (O.) khandesh .

Ventral aspects ( Fig. 9 ). As in O. (O.) khandesh .

Male genitalia ( Figs. 14–16 ). Symmetrical, robust, in profile arched. Phallobasis divided and membranous dorsally; phallobasis elongate (in profile) ( Fig. 15g ). Parameres applied closely to phallus and scarcely extended beyond phallus, apex of each feebly sclerotised with membranous projection ( Fig. 15e ). Phallus broad, dorsally shallowly concave anteriorly and projecting dorsolaterally forming two low humps (visible in lateral view) ( Fig. 15h ), thereafter attenuated anteriorly, apex broadly rounded, margin recurved ( Fig. 16j ).

Female. Unknown.

Diagnosis. Omorgus (O.) khandesh and O. (O.) rimulosus are very similar to each other. The two species can be told apart as discussed under the diagnosis of O. (O.) khandesh , above.

Distribution. Known only from the southeastern coast of the Indian subcontinent.

Figures

FIGURES 7–10. Omorgus (Omorgus) rimulosus (Haaf, 1957), holotype NHMB. 7, habitus, dorsal view; 8, habitus, lateral view; 9, habitus, ventral view 10, holotype labels.

FIGURES 11–16. Male genitalia in dorsal (11, 14) and lateral (12, 15) views, apex of median lobe (13, 16). Omorgus (Omorgus) khandesh Strümpher & Kalawate, new species, holotype (ZSI-WRC), 11–13. Omorgus (Omorgus) rimulosus (Haaf, 1957), holotype (NHMB), 14–16. a–j, for explanation refer to Table 1.

FIGURES 3–6. Omorgus (Omorgus) khandesh Strümpher & Kalawate, new species, holotype (ZSI-WRC). 3, habitus, dorsal view; 4, habitus, lateral view; 5, head and pronotum; 6, holotype labels.