Dichotomius (Cephagonus) seag Nunes & Vaz-de-Mello 2019, new species
Creators: name: Nunes, Rafael V.
name: Vaz-de-Mello, Fernando Z.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Dichotomius
Dichotomius seag

description: 2.6.: Dichotomius (Cephagonus) seag new species
(Figure 25)
Diagnosis. distinguished from the other species in the group by the following combination of characteristics: males ’ cephalic carina longer than wideı with a rounded apex (as in medium males of D. bicuspis of bicuspis group); anterior and posterior pronotum portions with very fine punctuation (viewed under 30x magnification); males ’ pronotal disc with a single-rounded lobe at the anterior portion (as in D. fissus of the same group); pronotal margin smooth and; elytral striae with indistinct punctuation.
● HOLOTYPEı male: GUYANNE FRANÇAISE: Cayenne: Nouragues Biological Reserve. Fezes Allouatta. iii-1997. F Feer [at CEMT].
● PARATYPES: same data of Holotype [1Ƌ]; SURINAME: Sipawilini. Palumeu River. 2³28 ’ Sı 55 ³37 ʹ W. iii-2012. T Larsen [2 ƋƋ at CEMT].
Description. (maleı holotype): BL: 23 mmı PW: 13 mm. Colour: blackı with brown elytra. Head: fronto-clypealı genal and inter-ocular surfaces smooth. Gena borders slightly curved inwards. Cephalic carina longer than wideı rounded at the apex. Pronotum: borders smoothı not serrated. Pronotal disc shinyı lacking punctuation and delimited anteriorly by a singleı rounded lobe. Anterior portionı including excavation and anterior angles with very fineı equally spaced punctures (viewed under 20x magnification). Posterior margin with two rows of small ocellate punctures. Metasternum: sides and anterior portion of anterior lobe covered by dense red setae. Setigerous punctuation equally spacedı where present. Elytra: striae weakly impressed lacking distinct punctuation. Striae expanding near the base forming foveae. Interstriae brown colourı lacking microsculpture. Abdomen: glabrousı punctuation of ventrites anterior margininterrupted medially. Aedeagus (Figure 21 (c-e)): parameraı apexes rounded dorsallyı convergent; longitudinal excavation taking 3/4 of paramera length; basal excavations rounded. Laterallyı subtle declivity towards apex; posterior margin with an emargination near junction with phalobasis. Ventrallyı sclerotised portion excavatedı forming a groove constrained at mid-portion; subgenital plate rounded at basis and emarginated at apex.
Morphological variation. male BL: 17 – 23 mmı PW: 9 – 13 mm. Female BL: 17 mmı`PW: 9 mm and is distinguished from males as follows: Head: fronto-clypeal surface with coarse puncture. Cephalic carina transversalı forming a weak pair of tubercles. Pronotum: simply convexı lacking lobes. Elytra: striae deeply impressedı punctures separated by twice their diameter. Abdomen: sixth ventrite bearing a pair of triangular projections reaching pygidium apical margin (Figure 9 (b)).
Distribution. French Guyanaı Suriname (Figure 20).
Etymology. named after the Société Entomologique Antilles Guyane (SEAG)ı responsible for the holotype collection.
description: Published as part of Nunes, Rafael V. & Vaz-de-Mello, Fernando Z., 2019, Taxonomic revision of Dichotomius (Cephagonus) Luederwaldt 1929 and the taxonomic status of remaining Dichotomius Hope 1838 subgenera (Coleoptera: Scarabaeidae: Scarabaeinae: Dichotomiini), pp. 2231-2351 in Journal of Natural History 53 (37) on pages 2301-2302, DOI: 10.1080/00222933.2019.1692088, http://zenodo.org/record/3665519