Chilotrogus matejiceki Miessen, Uliana & Keith, 2020

Miessen, Geoffrey, Uliana, Marco & Keith, Denis, 2020, Review of the genus Chilotrogus Reitter (Coleoptera: Scarabaeidae: Melolonthinae Rhizotrogini) in Iran with description of two new species, Zootaxa 4742 (1), pp. 181-193 : 185-188

Chilotrogus matejiceki Miessen, Uliana & Keith , new species

( Figs. 2 , 5 , 14–18 , 21, 22 , 25, 26 , 29, 30 , 45 , 47 )

Type material (9♂♂ and 3♀♀). Holotype, ♂ ( NMPC) labelled: “ E. Iran, Deh Bakhri | 1700—1750 m | 30.4– 3.5.1973 [printed] || Loc. no. 186 | Exp. Nat. Mus. | Praha [printed] || Chilotrogus [handwritten] | panotrogoides [handwritten] | Rtt. [handwritten] D Keith det [20]07 [printed]” . Paratypes: 1♂ ( CRS, CGM), same data as holotype ; 4♂♂ and 1♀ ( CMU, CJM): “dat. 27- 28.5.2014 Irán IR | Kerman prov. | Mijam ( Jiroft ) | N 28°52’29” E 57°53’01” | leg. Černý Fr., 1650 m.n.m. [printed]” ; 2♂♂ and 1♀ ( CRS, CGM): “ IRAN, Kerman prov. | 5 km S. Deh Bakhri | 28°59’N 57°55’E, 2300 m | 31. V.1997, A. Hofmann lgt.” ; 1♂ and 1♀ (allotypus) ( CRS), same data, but “ 31. V–1. VI.1997, leg. A. Hofmann & P. Kautt ” .

Description of the holotype (♂). Length 16.6 mm. Habitus dark brown and matt ( Fig. 5 ). Clypeus and forehead with large, strong and dense punctuation and traces of microscopic pilosity on the edges. Clypeus slightly larger than the distance between the eyes. Antennae with ten antennomeres, trimerous antennal club short, as long as funicle and scape together.

Pronotum glabrous with large, strong, dense and deep punctuation, the punctures slightly more spaced than those on clypeus and forehead. Lateral margins crenulate with thick setae, slightly shorter than those of epipleuron in the humeral area.

Elytra matt, pruinose with coarse punctuation, sparser on the interstriae. Pilosity very short and sparse, distributed over the entire surface. Epipleuron with long and thick pilosity, gradually shortening towards apex.

Protibiae tridentate, the basal tooth at the middle, the median tooth slightly closer to the apical. Inner spur inserted slightly behind the median tooth. Metatarsi elongate, 1.8 times longer than metatibiae which are dented on upper face. At the base of each dent is one thick and long seta.

Pygidium with raised setae in lateral view.

Aedeagus of characteristic shape; parameres ( Figs. 14–16 ) in dorsal view with a marked angle at the level of the central opening. Internal piece broadly open dorsally, exposing an internal tubular structure that bears a backwards protruding spine at the apex ( Figs. 17, 18 , 25 ).

Variability of males. Length: 16.1–17.5 mm. Parameres in dorsal view with the marked angle at the level of the central opening more or less developed ( Figs. 21, 22 ), internal piece also variable ( Figs. 25, 26 ).

Female. Length: 15.7–16.1 mm. Similar to male, but antennal club shorter, as well as the metatarsi.

Etymology. Dedicated to Jan Matějíček (Hradec Králové, Czech Republic), a specialist on Staphylinidae and keen collector of Scarabaeoidea, who entrusted one of us (MU) with the first specimen that we study.

Distribution. Currently only known from three nearby collecting sites on Jebal Barez mountain range, in southeastern Iran, between 1650 and 2300 m a.s.l. ( Fig. 47 ).

Differential diagnosis. Chilotrogus matejiceki new species appears to be externally indistinguishable from Ch. panotrogoides (cf. habitus in Figs. 2 , 5 and 1 , 6 ), and identification can be achieved only by examination of the male genitalia (cf. Figs. 9–13 and 14–18 ). Parameres of Ch. matejiceki new species are characterised by an angled to tooth-like projection of the internal margin, which marks the distal part of a broad basal concavity. The type series shows some degree of variability (including between syntopic specimens) in this trait (cf. Figs. 21, 22 ), that is however well distinct from the gently curved morphology of Ch. panotrogoides ( Figs. 19, 20 ). Additional differences are found in the distal part of the internal sclerite. Its dorsal spine is variable in elongation in both species, but in Ch. matejiceki new species it is broad at the base and flattened in its distal part ( Figs. 25, 26 ), while in Ch. panotrogoides the same spine is narrow at the base and is cylindrical in its distal part ( Figs. 23, 24 ). Also, the subcircular apex of the tube-like structure that bears the spine is almost completely occupied by soft tissue (evertible part of endophallus) in Ch. panotrogoides ( Figs. 23c, 24c ), while the same soft tissue occupies only about the lower half of the apex in Ch. matejiceki new species ( Figs. 25c, 26c ).

Females of the two species show very moderate differences in the genital sclerites ( Figs. 27–30 ), whose diagnostic value should be verified on a longer series.

Figures

FIGURE 47. Known distribution of Iranian Chilotrogus Reitter, 1905, based on verified records.

FIGURES 1–4. Male habitus of Iranian Chilotrogus Reitter, 1905. 1, Ch. panotrogoides Reitter, 1905, specimen from Iran: Sarbijan (Shinagara); 2, Ch. matejiceki Miessen, Uliana & Keith, new species, paratype from Iran: Mijam; 3, Ch. farsensis Keith, 2003, specimen from 40 Km NW Shiraz, Sangar; 4, Ch. schoolmeestersi Miessen, Uliana & Keith, new species, holotype.

FIGURES 5–8. Type specimens of Chilotrogus Reitter, 1905. 5, Ch. matejiceki Miessen, Uliana & Keith, new species, holotype and labels; 6, Ch. panotrogoides Reitter, 1905, holotype and labels; 7, Ch. panotrogoides, labels of false allotype in MHNG; 8, Ch. panotrogoides, labels of false paratype in MHNG.

FIGURES 14–18. Male genitalia of Ch. matejiceki Miessen, Uliana & Keith, new species, holotype. 14, aedeagus (endophallic sclerite dissected), right lateral view; 15, same, dorsal view; 16, same, apical view; 17: endophallic sclerite, dorsal view; 18, same, right lateral view.

FIGURES 19–22. Paramera of Ch. panotrogoides Reitter, 1905 (19, 20) and Ch. matejiceki Miessen, Uliana & Keith, new species (21, 22), extremes of variability, left inclined lateral view. 19, specimen from Iran: Sarbijan (Shinagara); 20, specimen from Iran: Kerman (holotype); 21, specimen from Iran: Deh Bakhri (holotype); 22, specimen from Iran: Mijam (paratype).

FIGURES 23–26. Endophallic sclerite of Ch. panotrogoides Reitter, 1905 (23, 24) and Ch. matejiceki Miessen, Uliana & Keith, new species (25, 26), extremes of variability. 23, specimen from Iran: Kerman (holotype); 24, specimen from Iran: Sarbijan (Shinagara); 25, specimen from Iran: Deh Bakhri (holotype); 26, specimen from Iran: Mijam (paratype). a, left lateral view; b, inclined lateral view; c, frontal view, apex of internal tubular structure in evidence. Red lines indicate the boundary between sclerotized and soft tissue on the apical meatus.

FIGURES 27–30. Female genitalia of Ch. panotrogoides Reitter, 1905 (27, 28) and Ch. matejiceki Miessen, Uliana & Keith, new species (29, 30). 27, 28, specimens from Iran: Sirjan; 29, specimen from Iran: Deh Bakhri (allotype); 30, specimen from Iran: Deh Bakhri (paratype).

FIGURES 45, 46. Detail of pronotal punctures. 45, Ch. matejiceki Miessen, Uliana & Keith, new species, paratype from Iran: Mijam; 46, Ch. farsensis Keith, 2003, specimen from Iran: 15 Km N Vazag, Kuh-e-Dinar.

FIGURES 9–13. Male genitalia of Ch. panotrogoides Reitter, 1905, holotype. 9, aedeagus (endophallic sclerite dissected), right lateral view; 10, same, dorsal view; 11, same, apical view; 12: endophallic sclerite, dorsal view; 13, same, right lateral view.