Cephalotes angustus
Creators: name: Oliveira, Aline Machado
name: Powell, Scott
name: Feitosa, Rodrigo Machado
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Formicidae
Cephalotes
Cephalotes angustus

description: The angustus species group
(Figs. 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
The angustus group was proposed by Kempf (1958a) based on the subgenus Harnedia of the genus Paracryptocerus, with 26 species divided into seven subgroups. De Andrade and Baroni Urbani (1999) reorganized this scheme, reducing the angustus group to Kempf’s angustus subgroup, which was composed by C. adolphi, C. angustus, C. goeldii, C. notatus (= P. (Harnedia) fleddermanni in Kempf, 1958a), C. pallidicephalus (= P. (Harnedia) striativentris in Kempf, 1958a), and C. targionii. These authors also addedC. conspersus in the group, which was considered by Kempf (1951) as a taxonomically isolated species, andtwo species described bythem, C. dentidorsum and C. palta. These last two speciesare known only from Colombia and werenot included in this study. All species in this group are exclusively South American.
In the morphological phylogeny by De Andrade and Baroni Urbani (1999, see their Fig. 24), this group was considered the sister group to the clade formed by the bruchi, fiebrigi and prodigiosus groups. The current phylogeny confirms the relationshipsbetweenthese groups (Fig. 54). The bruchi, fiebrigi and prodigiosus groups are recovered as monophyletic, but they render the angustus group paraphyletic, suggesting that all thesegroupsmight represent asinglelineage (Fig.54).
Morphologically, these groups share the declivous face of the propodeum continuous with its dorsal face, not meeting at a distinct propodeal angle, and with a variable number of spines, but differing by the anterior expansions of the gaster, which are a thin translucent lamella in the angustus group and a thick opaque lamella in bruchi, fiebrigi and prodigiosus groups. Although the phylogenetic data (Fig. 54) suggests theangustus, bruchi, fiebrigi andprodigiosus groups couldbe synonymized, we decidedto keepangustus asa valid groupuntil abroader phylogeny, including additional species from all these groups, isavailable. The Argentinianprodigiosus group was not included in the present study, due to itsabsence in Brazil. The discussion about bruchi and fiebrigi groups is presented in the fiebrigi group section below.
Diagnosis: In workers, body with appressedhairs (Fig.2h). Declivous face of propodeum continuous with dorsal face, not meeting at a distinct propodealangle,withavariablenumberofspines(Fig.2h).If onlytwopairs of spinesarepresenton propodeum, the anteriorone is neverthelongest, andthe posterioroneisnever longerthanthedeclivousface (Fig.2h). First tergite of gaster with anterior lamellar expansions translucent (Fig. 2r). Insoldiers, propodeumwithvariablenumberof spines, iftherearetwo pairs, the anterior one is never longer than the posterior. Anterior gastral expansions with a translucent lamella, usually very thin (Fig. 3o).
Brazilian species of angustus group
Cephalotes adolphi (Emery, 1906)
Obsolete combination: Cryptocerus adolphi
Cephalotes angustus (Mayr, 1862)
Obsolete combinantion: Cryptocerus angustus
= Cephalotes angustus clarior (Forel, 1912)
Obsolete combination: Cryptocerus angustus clarior
= Cephalotes cristatus ruficeps (Santschi, 1929)
Obsolete combination: Cryptocerus cristatus ruficeps
Cephalotes conspersus (Smith, 1867) Obsolete combinantion: Cryptocerus conspersus = Cephalotes denticulatus variegata (Forel, 1911)
Obsolete combination:Cryptocerus denticulatus var.variegata Cephalotes frigidus (Kempf, 1960)
Obsolete combination: Paracryptocerus frigidus Cephalotes gabicamacho newspecies
Cephalotes goeldii (Forel, 1912)
Obsolete combination: Cryptocerus goeldii
Cephalotes marycornnewspecies
Cephalotes monicaulyssea new species
Cephalotes notatus (Mayr, 1866)
Obsolete combination: Cryptocerus notatus
= Cephalotes fleddermanni (Kempf, 1958a)
Obsoletecombination:Paracryptocerus (Harnedia) fleddermanni Cephalotes pallidicephalus (Smith, 1876)
Obsolete combination: Cryptocerus pallidicephalus
= Cephalotes striativentris (Emery, 1894)
Obsolete combination: Cryptocerus striativentris Cephalotes targionii (Emery, 1894)
Obsolete combination: Cryptocerus targionii
= Cephalotes denticulatus (Emery, 1894)
Obsolete combination: Cryptocerus denticulatus
Key to the identification of Brazilian species of the angustus group of Cephalotes based on workers
(Figs. 4 a-p)
1 In lateral view, the second pair of pronotal spines is raised dorsally above the level of the anterior pronotal spines (Fig. 4c)........... C. adolphi
1’ In lateral view, the second pair of pronotal spines are in the same level of the anterior pronotal spines (Fig. 4d, e)...........................................2
2 First gastral sternite longitudinally costate (Fig. 4o)..... C.pallidicephalus
2’ Firstgastral sternitenot longitudinallycostate (Fig. 4m), but rugosities can be present (Fig. 4n).......................................................................................3
3 Ventral face of head with longitudinal rugosities towardsthe cephalic foramen (Fig. 4a).................................................................................... C.notatus
3’ Ventral face of head microalveolate. Rugosities can be present, but not towards the cephalic foramen (Fig. 4b)..................................................4
4 In dorsalview, lateral spinesof postpetiole longerthan themaximum width of its lamellar part (Fig. 4f).................................................... C.frigidus
4’ In dorsal view, lateral spines of postpetioleas long asor shorter than the maximum width of its lamellar part (Fig. 4g)......................................5
5 In lateral view, dorsum of petiole without a pair of denticles (Fig. 4h).................................................................................................... C. goeldii
5’ Inlateral view,dorsum of petiolewithapair of denticles (Fig. 4i)....................6
6 Pro-, meso- and metapleura striate longitudinally (Fig. 4d)................ ............................................................................................................... C. targionii
6’ Pro-, meso- and metapleura not striatelongitudinally; if they are striae, it is only on the propleura (Fig. 4e).................................................................7
7 Indorsal view, firstgastral tergite orange tolight brown, with a black lozenge-shaped patch in the middle (Fig. 4j)........................ C. conspersus
7’ In dorsal view, first gastral tergite black, with or without a pair of anterolateral colored spots, never with a median lozenge (Fig. 4k, l, p)............................................................................................................8
8 In dorsal view, first gastral tergite with appressed canaliculate hairs only, without simple hairs (Fig. 4k)...............................................................9
8’ Indorsal view, firstgastral tergite with someappressed canaliculate hairs and appressed simple hairs (Fig. 4l, p).............................................10
9 In ventral view, sternite of gaster microalveolate, withoutlongitudinal striae (Fig. 4m).................................................................................... C.angustus
9’ In ventral view, sternite of gaster with longitudinal striae (Fig. 4n)..... .............................................................................. C. monicaulyssea newspecies
10 Anterior portionoffirst tergiteof gaster, nearthe postpetiolarinsertion, without striae, with abundantappressed canaliculatehairs, the distance between each hair shorter than their length (Fig. 4l)................................ ............................................................................ C. gabicamacho new species
10’Anteriorportion offirsttergiteof gaster,nearthe postpetiolarinsertion,with shortstriaeand sparseappressedsimplehairs,the distancebetweeneachhair longerthantheir length (Fig.4p).................................. C. marycornnewspecies
Key to the identification of Brazilian species of the angustus group of Cephalotes based on soldiers
(Figs. 5 a-p)
1 Cephalic disc alveolate with suberect to erect hairs (Fig. 5a)............... .................................................................................................................. C. frigidus
1’ Cephalic disc foveate with subdecumbent to appressed hairs (Fig. 5 b-d).................................................................................................................2
2 In dorsal view, dorsumof mesosoma yellowish (Fig.5k). In lateral view pleurae black, with some yellowish macula (Fig. 5g)................... C.adolphi
2’ In dorsalview, dorsum of mesosoma predominantly black, sometimes with the apices of the lateral projections yellowish (Fig. 5j). In lateral view, the entire pleurae black to dark brown (Fig. 5h, i)..........................3
3 Cephalic disc wider than long, at most subquadrate (Fig. 5b)............4
3’ Cephalic disc longer than wide (Fig. 5c, d)...............................................5
4 Pronotum broader than the head width (Fig. 5j)..................... C. goeldii
4’Pronotumnarrowerorasbroadastheheadwidth(Fig.5k)....................... C.notatus
5 Firstgastralsternitewithlongitudinalrugosities(Fig.5l)........... C.pallidicephalus
5’ First gastral sternite withoutlongitudinalrugosities (Fig. 5m), striae can be presentlaterally, but the middle of the sterniteis smooth (Fig.5n)......6
6 In dorsal view, lateral margins of pronotum straight and subparallel (Fig.5e)...................................................................................................................................7
6’ In dorsal view, lateral margins of pronotum convex and converging posteriorly (Fig. 5f).................................................................................................9
7 Indorsal view, propodeal groove weaklyimpressed, marked onthesides butabsent medially (Fig.5f)........................................................ C. conspersus
7’ Indorsalview, propodealgroovestronglyimpressed (Fig.5e)..............................8
8 Foveae of cephalic disc very close, space between them shorter than their diameters; each fovea with an internal subdecumbent hair (Fig. 5d). Indorsal view, pronotal carina weak and interrupted in the middle by a superficial sulcus (Fig. 5f). Inlateral view, posterior pair of denticles of propodeum strongly bent dorsally with the apices curved anteriorly................................................................................................ C. targionii
8’ Foveaeof headsparse, space between most foveae equal to or longer than thediameter of eachfovea; each foveawith aninternal appressed hair (Fig. 5c). In dorsal view, pronotal carina weak and continuous (Fig.5e). In lateral view, posterior pair of denticles of propodeumgently bent dorsally with apices not curved anteriorly (Fig. 5i).............................. ............................................................................... C. gabicamachonew species
9 First sternite of the gaster without striae laterally (Fig. 5m). In dorsal view, anterior lamellae of gaster extending posteriorly as a carina (Fig. 5o - dotted line). Pronotal carina well marked, normally forming a crest (Fig. 5g, h)............................................................................... C. angustus
9’ First sternite of the gaster withstriae laterally (Fig.5n). In dorsal view, anterior lamellae of the gaster not extending posteriorly as a carina (Fig. 5p - dotted line). Pronotal carina weakly marked, not forming a crest (Fig. 5i).................................................. C. monicaulyssea new species
description: Published as part of Oliveira, Aline Machado, Powell, Scott & Feitosa, Rodrigo Machado, 2021, A taxonomic study of the Brazilian turtle ants (Formicidae: Myrmicinae: Cephalotes), pp. 1-52 in Revista Brasileira de Entomologia 65 (3) on pages 8-9, DOI: 10.1590/1806-9665-RBENT-2021-0028, http://zenodo.org/record/5512220