Cephalotes angustus (Mayr, 1862)

Oliveira, Aline Machado, Powell, Scott & Feitosa, Rodrigo Machado, 2021, A taxonomic study of the Brazilian turtle ants (Formicidae: Myrmicinae: Cephalotes), Revista Brasileira de Entomologia 65 (3), No. e 20210028, pp. 1-52 : 8-9

publication ID

https://doi.org/ 10.1590/1806-9665-RBENT-2021-0028

DOI

https://doi.org/10.5281/zenodo.5512234

persistent identifier

https://treatment.plazi.org/id/038587E5-FFF3-FFC8-FFDF-FF0BD196F86B

treatment provided by

Carolina

scientific name

Cephalotes angustus
status

 

The angustus species group

( Figs. 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8 , 9 View Figure 9 , 10 View Figure 10 , 11 View Figure 11 , 12 View Figure 12 , 13 View Figure 13 , 14 View Figure 14 , 15 View Figure 15 , 16 View Figure 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 View Figure 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 View Figure54 ). 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 View Figure54 ).

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 View Figure54 ) 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 View Figure 2 ). Declivous face of propodeum continuous with dorsal face, not meeting at a distinct propodealangle,withavariablenumberofspines( Fig.2h View Figure 2 ).If onlytwopairs of spinesarepresenton propodeum, the anteriorone is neverthelongest, andthe posterioroneisnever longerthanthedeclivousface ( Fig.2h View Figure 2 ). First tergite of gaster with anterior lamellar expansions translucent ( Fig. 2r View Figure 2 ). 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 View Figure 3 ).

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 View Figure 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 View Figure 4 )........... 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 View Figure 4 )...........................................2

2 First gastral sternite longitudinally costate ( Fig. 4o View Figure 4 )..... C.pallidicephalus

2’ Firstgastral sternitenot longitudinallycostate ( Fig. 4m View Figure 4 ), but rugosities can be present ( Fig. 4n View Figure 4 ).......................................................................................3

3 Ventral face of head with longitudinal rugosities towardsthe cephalic foramen ( Fig. 4a View Figure 4 ).................................................................................... C.notatus

3’ Ventral face of head microalveolate. Rugosities can be present, but not towards the cephalic foramen ( Fig. 4b View Figure 4 )..................................................4

4 In dorsalview, lateral spinesof postpetiole longerthan themaximum width of its lamellar part ( Fig. 4f View Figure 4 ).................................................... C.frigidus

4’ In dorsal view, lateral spines of postpetioleas long asor shorter than the maximum width of its lamellar part ( Fig. 4g View Figure 4 )......................................5

5 In lateral view, dorsum of petiole without a pair of denticles ( Fig. 4h View Figure 4 ).................................................................................................... C. goeldii

5’ Inlateral view,dorsum of petiolewithapair of denticles ( Fig. 4i View Figure 4 )....................6

6 Pro-, meso- and metapleura striate longitudinally ( Fig. 4d View Figure 4 )................ ............................................................................................................... C. targionii

6’ Pro-, meso- and metapleura not striatelongitudinally; if they are striae, it is only on the propleura ( Fig. 4e View Figure 4 ).................................................................7

7 Indorsal view, firstgastral tergite orange tolight brown, with a black lozenge-shaped patch in the middle ( Fig. 4j View Figure 4 )........................ 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 View Figure 4 )............................................................................................................8

8 In dorsal view, first gastral tergite with appressed canaliculate hairs only, without simple hairs ( Fig. 4k View Figure 4 )...............................................................9

8’ Indorsal view, firstgastral tergite with someappressed canaliculate hairs and appressed simple hairs ( Fig. 4l, p View Figure 4 ).............................................10

9 In ventral view, sternite of gaster microalveolate, withoutlongitudinal striae ( Fig. 4m View Figure 4 ).................................................................................... C.angustus

9’ In ventral view, sternite of gaster with longitudinal striae ( Fig. 4n View Figure 4 )..... .............................................................................. 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 View Figure 4 )................................ ............................................................................ C. gabicamacho new species

10’Anteriorportion offirsttergiteof gaster,nearthe postpetiolarinsertion,with shortstriaeand sparseappressedsimplehairs,the distancebetweeneachhair longerthantheir length ( Fig.4p View Figure 4 ).................................. C. marycornnewspecies

Key to the identification of Brazilian species of the angustus group of Cephalotes based on soldiers

( Figs. 5 View Figure 5 a-p)

1 Cephalic disc alveolate with suberect to erect hairs ( Fig. 5a View Figure 5 )............... .................................................................................................................. C. frigidus

1’ Cephalic disc foveate with subdecumbent to appressed hairs ( Fig. 5 View Figure 5 b-d).................................................................................................................2

2 In dorsal view, dorsumof mesosoma yellowish ( Fig.5k View Figure 5 ). In lateral view pleurae black, with some yellowish macula ( Fig. 5g View Figure 5 )................... C.adolphi

2’ In dorsalview, dorsum of mesosoma predominantly black, sometimes with the apices of the lateral projections yellowish ( Fig. 5j View Figure 5 ). In lateral view, the entire pleurae black to dark brown ( Fig. 5h, i View Figure 5 )..........................3

3 Cephalic disc wider than long, at most subquadrate ( Fig. 5b View Figure 5 )............4

3’ Cephalic disc longer than wide ( Fig. 5c, d View Figure 5 )...............................................5

4 Pronotum broader than the head width ( Fig. 5j View Figure 5 )..................... C. goeldii

4’Pronotumnarrowerorasbroadastheheadwidth( Fig.5k View Figure 5 )....................... C.notatus

5 Firstgastralsternitewithlongitudinalrugosities( Fig.5l View Figure 5 )........... C.pallidicephalus

5’ First gastral sternite withoutlongitudinalrugosities ( Fig. 5m View Figure 5 ), striae can be presentlaterally, but the middle of the sterniteis smooth ( Fig.5n View Figure 5 )......6

6 In dorsal view, lateral margins of pronotum straight and subparallel ( Fig.5e View Figure 5 )...................................................................................................................................7

6’ In dorsal view, lateral margins of pronotum convex and converging posteriorly ( Fig. 5f View Figure 5 ).................................................................................................9

7 Indorsal view, propodeal groove weaklyimpressed, marked onthesides butabsent medially ( Fig.5f View Figure 5 )........................................................ C. conspersus

7’ Indorsalview, propodealgroovestronglyimpressed ( Fig.5e View Figure 5 )..............................8

8 Foveae of cephalic disc very close, space between them shorter than their diameters; each fovea with an internal subdecumbent hair ( Fig. 5d View Figure 5 ). Indorsal view, pronotal carina weak and interrupted in the middle by a superficial sulcus ( Fig. 5f View Figure 5 ). 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 View Figure 5 ). In dorsal view, pronotal carina weak and continuous ( Fig.5e View Figure 5 ). In lateral view, posterior pair of denticles of propodeumgently bent dorsally with apices not curved anteriorly ( Fig. 5i View Figure 5 ).............................. ............................................................................... C. gabicamachonew species

9 First sternite of the gaster without striae laterally ( Fig. 5m View Figure 5 ). In dorsal view, anterior lamellae of gaster extending posteriorly as a carina ( Fig. 5o View Figure 5 - dotted line). Pronotal carina well marked, normally forming a crest ( Fig. 5g, h View Figure 5 )............................................................................... C. angustus

9’ First sternite of the gaster withstriae laterally ( Fig.5n View Figure 5 ). In dorsal view, anterior lamellae of the gaster not extending posteriorly as a carina ( Fig. 5p View Figure 5 - dotted line). Pronotal carina weakly marked, not forming a crest ( Fig. 5i View Figure 5 ).................................................. C. monicaulyssea new species

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Formicidae

Genus

Cephalotes