Pelecium igneus Orsetti & Lopes-Andrade

Orsetti, Artur & Lopes-Andrade, Cristiano, 2016, A new species of Pelecium Kirby (Coleoptera: Carabidae: Peleciini) from the Atlantic Forest biome, Brazil, Zootaxa 4179 (1), pp. 123-127 : 124

Pelecium igneus Orsetti & Lopes-Andrade , sp. nov.

Figs 1−12

Type locality. “ Estação de Pesquisa, Treinamento e Educação Ambiental Mata do Paraíso ” (officially abbreviated as “ EPTEA Mata do Paraíso ”) in Viçosa, state of Minas Gerais, Southeast Brazil (20°48'08.0"S 42°51'21.7"W).

Etymology. The specific epithet is from the Latin “ igneus ”, which means “on fire”, in reference to the reddish reflexes on pronotum and head.

Diagnosis. A medium sized species (13 mm) distinguishable among other congeners by the combination of the following features: Fore body dorsum is bright metallic and thence contrasts sharply with the black elytra ( Fig. 1 ). Head with frontal impressions punctiform ( Figs 1, 3 ), with a short and shallow excavation. Pronotum with median line shallow ( Fig. 1 ), barely discernible, deeper posteriorly; basal impressions very shallow. Apical labial and maxillary palpomeres triangular ( Fig. 4 ). Adults of P. i gn e us and P. helenae are quite similar in the shape of the body, frontal fovea of head, median line and basal impressions of pronotum. However, in P. igneus the lateral edges of pronotum are more arcuate near base, giving it a subcordate shape when seen from above. Moreover, in P. igneus the elytra is comparatively rounder when seen from above and is shiny black, contrasting with its metallic reddish pronotum. In P. helenae , the dorsum is homogeneously violaceus.

Description, male holotype ( Figs 1–12 ). Fully pigmented adult. Measurements in mm: AL1-11: 0.81, 0.48, 0.55, 0.52, 0.56, 0.50, 0.44, 0.45, 0.43, 0.45, 0.65, EL 6.89, EW 5.18, lp2L 0.57, lp3L 0.83, lp3 W 0.51, mp3L 0.24, mp4L 0.68, mp4 W 0.46, PL 3.85, PW 3.83, SL 0.49, SW 0.67, TL 12.85. Ratio: TL/EW 2.48. Body ovate and flat; discs of head and pronotum metallic wine reddish in dorsal view, with greenish and yellowish reflections along sides ( Fig. 1 ); elytra shiny black ( Fig. 1 ), glabrous, with only standard setae present (supraorbital, pronotal and parascutellar setae); ventral surface shiny black ( Fig. 2 ), Head microreticulate, with a pair of frontal punctiform fovea, each with a short and shallow excavation at the outer side ( Fig. 3 , arrows). Mouth parts ( Fig. 4 ): apical labial and maxillary palpomeres triangular, with long and sparse yellowish setae, surface mostly reddish brown, with apicalmost portion yellowish; fourth maxillary palpomere subtriangular, 2.8X as long as the third palpomere, covered with sparse yellowish slender setae, surface reddish brown, with apicalmost portion yellowish. Pronotum ( Fig. 1 ) subcordate, minutely rough (in low magnification) to transversely microstriate (in magnification above 100X); lateral margins rounded in apical 4/5, sinuate just in front of basal angles; base truncate, with sides strongly oblique towards highly obtuse and blunt basal angles; median line fine and shallow, deeper posteriorly; basal impressions inconspicuous. Scutellum triangular ( Fig. 1 ), minutely rough (in low magnification) to microreticulate (in magnification above 100X). Elytra with inner five interneurs deep; in between interneurs shiny and unpunctate, minutely rough (in low magnification) to transversely microstriate (in magnification above 100X). Protibiae ( Fig. 2 ) expanded at apex. Mesotibiae ( Fig. 2 ) not expanded at apex; densely pubescent ventrally, more ventroapically. Metatibiae ( Fig. 2 ) slender, densely pubescent in apical half of ventral side. Abdominal tergite IX ( Fig. 12 ) oval, asymmetric, with anterior portion narrowed to a sharp apex; posterior portion with asymmetric expansions on each side; posterior edge barely curved and growing to an obtuse angle. Aedeagus ( Figs 5−11 ) with penis ( Figs 5−9 ) cylindrical, slender, conspicuously curved in lateral views ( Figs 6, 8, 9 ), its apical edge straight ( Figs 5, 7 ); parameres asymmetric ( Figs 7, 10−11 ), left paramere ( Fig. 10 ) longer and narrower than right paramere ( Fig. 11 ).

Type series. Holotype ♂ ( CELC), labeled “ BRASIL: MG, Viçosa Mata do Paraíso , 08.xii.2014 pitfall, trilha do pesquisador leg. A. Orsetti \ Pelecium igneus Orsetti & Lopes-Andrade HOLOTYPUS [printed in red paper]”.

Comments. The sexsetose labrum, combined with quadrisetose pronotum, defines Pelecium igneus as a member of the subgenus Pelecium (s. str). Pelecium igneus is the unique species in the genus in which the color of head and pronotum is different from the color of elytra. We include P. i g ne u s in P. rotundipenne species group based on the following features: head frontal fovea punctiform, pronotum basal impression moderately deep to shallow, elytral interneurs 6 and 7 absent, interneurs 5 absent or reduced ( Straneo & Ball 1989). It is necessary to alter part of the definition of the P. rotundipenne group, which now includes species with black colored, coppery, violaceus and partially reddish dorsum.

Pelecium igneus sp. nov. can be identified using key in Straneo & Ball (1989), with couplets 25 and 26 modified in the following way:

25(24’) Elytron with only discal interneurs 1–4 deep, and only interneur 1 extended to apical declivity, 4 remote from base and apex. Pronotum with posterolatera1 impressions indistinct, shallow. ............................................................................. P. purpureum 25'. Elytron with at least interneurs 1–5 moderately deeply impressed, and extended to rather gradually sloped apical declivity. Pronotum with posterolateral impressions various. ............................................................................................................... 25a 25a(25’) Pronotum with sides markedly rounded; posterolateral impressions evident. ............................................................. P. paulae 25a’ Pronotum with sides less rounded, subsinuate to sinuate posteriorly; posterolateral impressions indistinct. ......................... 26 26(25a’) Pronotum reddish, with green reflections laterally. Elytra black, with violaceous reflections. ......................... P. igneus sp. n. 26’ Dorsum unicolored dark purplish, without green reflections laterally. ...................................................................... P. helenae

Figures

FIGURES 1 – 4. Pelecium igneus Orsetti & Lopes-Andrade sp. nov., male holotype. 1, 3 dorsal view 2, 4 ventral view. 3. Head, arrowhead points to excavations of frontal fovea 4. Detail of labial and maxillary palpomeres. Scale bars: 5 mm (1 − 2); 1 mm (3 − 4).

FIGURES 5 – 12. Pelecium igneus Orsetti & Lopes-Andrade sp. nov., male holotype. Aedeagus (5 – 8) 5. Dorsal view 6. Left lateral view 7. Ven tr a l v ie w 8. Right lateral view 9. Penis, right lateral view 10. Left paramere 11. Right paramere 12. Tergite IX. Scale bar: 0.5 mm.