Trogellus (Trogoides) trajectus Paulsen, 2018

Paulsen, M. J., 2018, Generic changes in the stag beetle tribe Aesalini (Coleoptera: Lucanidae: Aesalinae) with the description of two new species, Insecta Mundi 666, pp. 1-10 : 7-9

Trogellus (Trogoides) trajectus Paulsen , new species

Type material. Holotype male, KSEM, labeled: a) “ PANAMA: Darién / Cana Biological Station / Serranía de Pirre , 1200 m / 7°45′18″N, 77°41′6″W / 04–07 Jun 1996; J. Ashe, / R. Brooks, PAN1AB96 105 / ex: flight intercept trap ”; b) database label “SM0043836 / KUNHM–ENT”; c) on red paper, “ Trogellus / trajectus Paulsen ♂ / HOLOTYPE ” . Allotype female, KSEM, labeled: a) “ PANAMA: Darién / Cana Biological Station / Serranía de Pirre , 1200–1400 m / 7°45′18″N, 77°41′6″W / 05 Jun 1996; J. Ashe, / R. Brooks, PAN1AB96 043 / ex: fungusy log”; b) database label “SM0039755 / KUNHM–ENT”; c) on red paper, “ Trogellus / trajectus Paulsen ♀ / ALLOTYPE ” . Paratype female, MJPC, labeled: a) as holotype; b) database label “SM0043845 / KUNHM–ENT”; c) on yellow paper, “ Trogellus / trajectus Paulsen ♀ / PARATYPE ” .

Description. Holotype male ( Fig. 8 ). Length: 4.5 mm. Width: 2.4 mm. Color: Everywhere dark reddish brown. Vestiture: Dorsally scales consisting of two types: erect bristles and brownish gray tomentosity (obscuring color of integument). Head: Canthus long (reaching pronotum when head retracted) and broad. Eye dorsally narrowed. Clypeus triangular, apex not distinctly produced. Mentum bifoveate. Mandibles weakly dentate externally at basal angulation. Pronotum: Surface densely punctate, some punctures with erect bristles (lacking distinct tubercle), remaining punctures obscured by tomentous scales. Metasternum: Punctures anterolaterally large in size. Elytra: Surface everywhere with moderate punctures obscured by tomentous scales, and with rows of moderate punctures with blunt bristles and a shiny tubercle anteriorly; bristles moderately long (2X longer than 4 th metatarsomere). Legs: Protibiae tridentate, teeth subtriangular; margin between teeth more concave than in other species. Mesotibia with 2 larger external teeth, 1-2 smaller teeth, and acute apex. Metatibia straight, with 1–2 small median teeth and 1–2 smaller teeth proximally; apex acute. Male genitalia: Parameres narrow and elongate, 1/2 as long as median lobe, appressed to median lobe; median lobe symmetrical, with moderate, rounded lateral processes at distal third ( Fig. 8d ).

Description. Allotype female, paratype female, differing from the holotype in the following. Length: 4.5–4.6 mm. Width: 2.5–2.6 mm. Legs: Metatibia with external teeth almost obsolete, apex tumid. Female genitalia: Not examined.

Remarks. This species is a member of the subgenus Trogoides Paulsen based on the lateral projections on the median lobe of the male genitalia. Uniquely in this species the lobes are rounded, not triangular ( Fig. 8d ). The external protibial teeth are more triangular in this species making the external margin more concave between them, while a flat margin had been a uniting character for the rest of the species in the subgenus. This is a matter of degree, and species in other subgenera possess a distinctly concave margin. Interestingly, the dorsal bristles of T. trajectus are occasionally blunt, but for the most part distinctly acute, which removes blunt bristles as a useful character for delineating the subgenus.

Etymology. The name is a Latin adjective in the nominative singular referring to “crossing over, a passage”, a reference to the species’ location in the Darién Gap and its potential to also occur in South America.

Distribution. PANAMA: Darién: Cana Biological Station. The type locality is less than 7 km from Colombia, so this species is likely to occur in that country. When discovered it is expected to qualify the genus as a member of the South American fauna.

Figures

Figures 8–9. Trogellus Paulsen species. 8) Trogellus trajectus Paulsen, new species, holotype male. a) Dorsal habitus. b) Oblique lateral habitus. c) Labels of holotype. d) Male genitalia. ventral view. 9) Trogellus maesi Paulsen, male. a) Dorsal habitus. b) Male genitalia, ventral view.