Omorgus (Omorgus) triestinae Pittino, 1987

Huchet, Jean-Bernard & Costa-Silva, Vinicius Da, 2018, A new species of Polynoncus Burmeister, 1876 from Brazil (Coleoptera: Trogidae), Zootaxa 4524 (5), pp. 553-566 : 559-561

Reinstatement of Omorgus (Omorgus) triestinae Pittino, 1987

( Figs. 14–18 )

Type material examined. HOLOTYPE ♂ and seven paratypes: “Muséum Paris, Brésil, Minas-Geraes, de Castelnau 1847 / 7/47” ( MNHN).

Other specimens examined. 102 specimens . “ BOLIVIA: Santa Cruz, Chiquitos, 1,6 km ESSE Santiago de Chiquitos , 622m, 18°12'04”S, 59°21'00”W, XI.2008, carcass, W.D. Edmonds leg.” (5♂, 5♀ CEMT). “ BRAZIL: Distrito Federal, Planaltina, ESEC Águas Emendadas , 15°32'31”S, 47°36'49”W, 16-31.XI.2009, M.R. Frizzas leg.” (6♂, 1♀ CEMT) ; “ Planaltina, ESEC Águas Emendadas , 15°32'31”S, 47°36'49”W, 1-15.XI.2009, M.R. Frizzas leg.” (8♂, 4♀ CEMT) ; “ Planaltina, ESEC Águas Emendadas , 15°32'31”S, 47°36'49”W, 16-31. XII.2009, M.R. Frizzas leg.” (2♀ CEMT) ; “ Planaltina, ESEC Águas Emendadas , 15°32'31”S, 47°36'49”W, 16-31.X.2009, M.R. Frizzas leg.” (1♂, 4♀ CEMT) ; “ Planaltina, ESEC Águas Emendadas , 15°32'31”S, 47°36'49”W, 1-15.I.2010, M.R. Frizzaz leg.” (1♂ CEMT) ; “ Planaltina, ESEC Águas Emendadas , 15°32'31”S, 47°36'49”W, I.2011, M.R. Frizzas leg.” (5♂, 4♀ CEMT) ; “ Brasília, Parque Nacional de Brasília , 15°43'46”S, 47°57'23”W, 24.XI.2016, Interceptação de voo, M.V.C. Rocha leg.” (1♂ CEMT) ; “ Brasília, Parque Nacional de Brasilia , 15°51'22”S, 47°48'48”W, 21. XII.2015, N.H.D. Silva leg.” (1♂, 1♀ CEMT) ; “ Brasília, Parque Nacional de Brasilia , 12.I.2016, N.H.D. Silva leg.” (1♂ CEMT) . “ Goias, Parque Nacional das Emas , [18°7'20”S, 52°54'30”W], 1999, G. Machado leg.” (2♂, 1♀ CEMT) ; “ Jataí, Fazenda Nova Orlândia , I.1964, Martins, Morgate & Silva leg.” (1 MZSP) . “ São Paulo, Itirapina, Estação Ecológica de Itirapina , 735m, 22°13'56”S, 47°52'58”W, 30.I.2009, Fernando Silva leg.” (1♂ CEMT) ; “ Itirapina, Estação Ecológica de Itirapina , 735m, 22°13'56”S, 47°52'58”W, 2. II.2000, G. Machado leg.” (1♂ CEMT) ; “ Itirapina, Estação Ecológica de Itirapina , 22°15’S, 47°49’W, 14.V.2001 à 15.I.2002, Equipe Biota leg.” (16 MZSP) ; “ Marília , I.1948 ” (1 MZSP) ; “ Ribeirão Preto, Fac. Medicina , XI.1954, M.P. Barretto leg.” (4♀ MZSP) ; “ Ribeirão Preto, Fac. Medicina , I.1955, M.P. Barretto leg.” (1♂, 1♀, 4 unsexed MZSP) ; “ Itu, Faz. Pau d’Alho , II. 1959, U. Martins leg.” (1♂ MZSP) ; “ Pirassununga , 18.XI.1940, Schubart leg.” (1 MZSP) ; “ Pirassununga , 27.X.1945, Schubart leg.” (1 MZSP) ; “ Pirassununga , 6.I.1946, Schubart leg.” (1 MZSP) ; “ Pirassununga , 3. III.1945, Schubart leg.” (1 MZSP) ; “ Anhembi , XI.1957, E. Dente leg.” (1 MZSP) ; “ Botucatu , 22.II.1955, Werner leg.” (1♀, 1 unsexed MZSP) . “ Ibirá , X.1953, Dirings leg.” (1♀ MZSP) . “ Mato Grosso do Sul, Porto Murtinho , I.1930, R. Spitz leg.” (1 MZSP) ; “ Porto Murtinho , XI.1929, R. Spitz leg.” (1 MZSP) . “ Minas Gerais, Uberlândia, Campus UFU [= Universidade Federal de Uberlândia ], [18°55'06”S, 48°15'28”W], 11.II.2006, J. Mendes leg.” (1♀ CEMT) . “ PARAGUAY: Concepcíon, Zanja Moroti , 30.I.2005, P. Gandini leg." (3♂, CJBH) .

Species validation. Omorgus (Omorgus) triestinae was described by Pittino (1987) based upon a series of 12 specimens from Minas-Geraes ( Brazil) curated at the MNHN, Paris ( France). In all likelihood, all the specimens from the type series were collected by F. Laporte de Castelnau himself during his expedition in South America (1843–1847), the results of which were subsequently published in several volumes ( Laporte 1850 –1861).

According to Pittino (1987), this new species is closely allied to O. (Omorgus) suberosus ( Fabricius, 1775) and O. (Omorgus) howelli (Howden & Vaurie, 1957) , but can be distinguished from both species by the presence of well-developed elytral tubercles (barely raised or obsolete in O. suberosus and O. howelli ) as well as the characteristic and very distinctive shape of the aedeagus with parameres spaced basally, widely exposing median lobe ( Figs. 15–16 ), and finally by the presence of a sclerotized piece within the endophallus ( Fig. 18 ).

In his revision of the Trogidae of South America, Scholtz (1990: 1407), after having examined the holotype and three paratypes of Pittino's species, considered that this species corresponds, “ without doubt”, to O. suberosus and placed consequently O. triestinae in synonymy with O. suberosus . In this regard, Scholtz mentioned: “ The holotype is a somewhat unusual form with tomentose elytral costae (…). The male genitalia, claimed by the author to be quite different from those of suberosus , merely have the paramere apices far apart (probably an artefact of the dissection to remove them), and the internal sac armature, which was also claimed to be unique, varies greatly within the species.

The recent study of more than five hundred South American trogid specimens related to “ O. suberosus ” from different institutions (CEMT, CJBH, MNHN, MZSP, and ZUEC), complemented by the examination of the type series of O. triestinae provides clear evidence that the morphological characteristics mentioned by Pittino (1987) in his diagnosis are perfectly applicable and constant within many specimens of the studied material. Moreover, as clearly illustrated here ( Figs. 15-18 ), the male genitalia are specific and distinct from those of O. suberosus ( Figs. 20–22 ), indicating that we are not observing the expression of a clinal morphological variation of a polymorphous species within its geographical area. Omorgus triestinae is restricted to central South America, to the Cerrado and Pantanal biomes, as well as an area of transition between the Cerrado and Atlantic Forest. Both biomes present little anthropic disturbance when compared to other biomes of South America. Thus, it appears that Omorgus triestinae is sensitive to anthropic actions, also differing from the widespread Omorgus suberosus . These morphologic features lead us to propose herein the restoration of O. triestinae as valid species. The main diagnostic morphological differences between both species are summarized in Table 1.

Remark. Vaurie (1962: 145) suspected that some “unusual” specimens of O. suberosus from Bolivia, Brazil, and Paraguay could belong to a different species based on the shape of the tubercles and distinctly elevated costae. She stated: “ Three or four specimens from Santa Cruz, Bolivia, some from Paraguay, and one from Batataes, Brazil, have the tubercles of at least the two inner principal rows of each elytron much more elevated than usual

and with a heavier tomentosity; the males have slightly different genitalia. Possibly these represent another species, but I believe that they are variants of suberosus .“ Distribution ( Fig. 23 ). Central part of South America.

Figures

FIGURES 14–18. Omorgus triestinae Pittino, 1987, male. 14, habitus, dorsal view (red arrows indicate discontinuous yellow tomentosity and white arrows indicate median-basal and lateral-basal tubercles of pronotum); 15, aedeagus, dorsal view; 16, aedeagus, with parameres intentionally spread out to show the shape of the median lobe; 17, aedeagus, lateral view; 18, sclerotized piece of the endophallus (Drawings courtesy (figs. 15 and 18): R. Pittino).

FIGURES 19–22. Omorgus suberosus (Fabricius, 1775), male. 18, habitus, dorsal view; 19, aedeagus, ventral view; 20, aedeagus, with parameres intentionally spread out to show the shape of the median lobe; 21, aedeagus, lateral view (Drawings courtesy (fig. 20): R. Pittino).

FIGURES 23–24. Distribution maps. 23, Omorgus triestinae Pittino, 1987; 24, Omorgus suberosus (Fabricius, 1775).