Cephalotes gabicamacho, Oliveira & Powell & Feitosa, 2021

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 : 11-13

Cephalotes gabicamacho new species

urn:lsid:zoobank.org:act:F19B756C-3FA8-45BB-AA3F-9D9480071D8F Figs. 8 a-c, 9a-c,10a-c, 15

Holotype: BRAZIL: MG, Uberlândia, Clube de Caça e Pesca Itororó , -19.00473 -48.31253, S.Powellcol./C06-94, DZUP 550148 (worker) [ DZUP].

Paratypes: samedataas holotype: DZUP 550149 (2 workers), DZUP 550150 (1 worker, 1 soldier), DZUP 550151 (1 soldier, 1 gyne), DZUP 550152 (1 gyne) [ DZUP], DZUP 550159 (1 worker, 1 soldier) [ MZSP], DZUP 550157 (1 worker, 1 soldier) [ USNM]; -19.00124 -48.31239, S. Powellcol. /C05-134, DZUP 550153 (3 workers), DZUP 550154 (2 soldiers) [ DZUP], DZUP 550158 (1 worker, 1 soldier) [ MZSP], DZUP 550156 (1 soldier) [ USNM], DZUP 550163 (2 workers), DZUP 550162 (1 soldier) [ INPA ], DZUP 550161 (2 workers) DZUP 550160 (1 soldier) [ MPEG], Paraopeba, iii.2011, C.R. Ribas, Cerrado, pitfall arbóreo [unique specimenidentifier UFV-LABECOL-004439] (1 worker) [ DZUP].

Diagnosis: Amemberoftheangustus speciesgroup.In workers,propleura striate. Firstgastral sternite microalveolate, without striae ( Fig. 4m ). First gastraltergiteanteriorlywithoutstriae,withabundantappressedcanaliculate hairs, thedistance betweeneachhairshorterthantheir length, appressed simplehairspresentonmiddleof tergite ( Fig.8c ). Insoldiers,indorsalview, lateral margins of pronotum straight and subparallel ( Fig. 9c ). Propodeal groove strongly impressed, forming a depression ( Fig. 9c ).

Worker measurements (N=15): HL 0.95-1.20; HW 0.98-1.28; EL 0.30-0.34; PW 0.82-1.03; WL 1.10-1.24; PTL 0.18-0.23; PTW 0.53-0.60; PPL 0.22-0.25; PPW 0.54-0.63; GL 1.40-1.64; HBL 0.35-0.40; HBW 0.08- 0.10; TL 3.85-4.46; CI 95.1-120; OI 24.9-31.6; PI 30-38.3; HBI 20-26.3.

Worker description: Body black; frontal lobes, anterior spots on gastral tergite, apices of each segment of legs, and external face of tibiae yellowish ( Fig. 8 ).

Mandibles, legs andgaster microalveolate.Head, mesosoma, petiole and postpetiole foveate-microalveolate. Propleura totally striate. Declivous face of propodeum sparsely striate.

Body with appressed canaliculate hairs ( Fig.8c ), more concentrated on meso- and metapleura. Mandibles and anterior margin of clypeus with suberect clavate and simple hairs ( Fig. 8a ). Declivous face of propodeum glabrous. First sternite of gaster with long erect simple hairs ( Fig. 8b ). Posterior edge of the gastral tergites with erect hairs.

Head slightly wider than long (CI 95.1-120), dorsum slight convex ( Fig.8b ). Mandibleswithweaklydevelopedlateral angle.Anteriormargin of clypeus concave, without lateral denticle. Frontal carinae notched anteriorly to eyes, not bent dorsally over eyes ( Fig. 8c ). Antennae with three-segmented club. Lateroventral margins of head with posterior carinae extending posteriorly to eyes until vertexal corners. Vertexal corners with narrow, irregular lamellar expansion ( Fig. 8a ).

Mesosomaweaklyconvexinlateralview ( Fig.8b ).Indorsalview,lateral margins of pronotum with three denticles, anterior two acute, posterior broadandsometimesbifid,almostformingfourthdenticle; promesonotal grooveabsent ( Fig.8c ).Mesonotumwithapairofshortdenticles.Propodeal grooveimpressed only laterally.Dorsal anddeclivous facesof propodeum continuous, not meeting in a distinct propodeal angle; lateral margins of propodeum with variable number of denticles ( Fig. 8c ). Femora not angulated dorsally, mid and hind basitarsi not flattened, with subparallel dorsal and ventral faces.

Indorsalview,anteriormarginof petioleconcave,laterallywithpairof spines ( Fig. 8c ), dorsum with a pair of tiny denticles ( Fig. 8b ), subpetiolar process broader anteriorly with narrow translucent lamellae ( Fig. 9b ). Postpetiole wider and longer than petiole ( Fig. 8c ), with a pair of spines curvedbackwards broader than spines of petiole, dorsum without carina ordenticles ( Fig.8c ), subpostpetiolarprocesspronouncedandcompressed anteroposteriorly ( Fig. 8b ).

Gaster suboval, deeply concave anteromedially, with broad anterior lamellar expansions, not extended posteriorly in a carina ( Fig. 8c ).

Soldiermeasurements (N=10):HL1.43-1.72;HW1.15-1.58;EL 0.33-0.36; PW 1.18-1.48;WL 1.40-2.00;PTL 0.20-0.33;PTW 0.53-0.68; PPL0.28-0.32; PPW 0.63-0.73;GL 1.72-2.06; HBL 0.36-0.42; HBW 0.10-0.12;TL 5.17-6.09; CI 77.1-98.2; OI 20.1-28.3; PI 34.4-50.8; HBI 23.8-31.6.

Soldierdescription: Bodyblack; dorsumandlateralofhead,apices of femora andexternalface of tibiaeferruginous.Firstgastral tergite with an anterior and a posterior pair of yellowish spots, each one occupying less than one third of the firsttergite length; posterior margins of eachtergite and sternite yellowish ( Fig. 9 ).

Sculpturingasintheworkers,exceptbypropleurawithstriaenotfully occupying the propleura, often on the lower part of the surface ( Fig. 9b ). Pilosity as in the workers, expect by gaster, which has appressed simple hairs ( Fig. 9b, c ).

Headlongerthanwide (CI 77.1-98.2).Mandibleswithastronglongitudinal lateral angle. Clypeusslightlyconcave without a pair of denticles ( Fig.9a ). Dorsumofheaddiscshapedandslightlyconcaveanteriorly.Frontalcarinae crenulateanteriorly.Antennalclubill-defined.Roof ofantennalscrobeswith a lateral carinae and a posterior denticle ( Fig. 9b ). Lateroventral margins of head without carinae. Vertexal corners forming pointed projections separated of the dorsum cephalic disc ( Fig. 9a, b ).

In lateral view, pronotum ascending, with a transversal carina not raisedinacrest; pronotalcarinaweaklydeveloped, notcrenulate,medially interrupted ( Fig. 9c ). In dorsal view, anterior margin of pronotum gently rounded, lateralmargins subparallel, with a pair of anterior denticles. Mesonotumandpropodeumdiscontinuousandflat ( Fig.9b ); mesonotum withapairofbluntroundedprojections;propodealgroovewellimpressed; dorsal and declivous faces of propodeum meeting in a distinct propodeal angle ( Fig.9b ); indorsalview, lateralmarginsof propodeumwithtwo pairs of projections, the anterior obtuse, the posterior acute, short, not curved anteriorly ( Fig. 9b ). Legs as in the worker.

In dorsal view, anterior margin of petiole slightly concave, laterally with a pair of spines curved backwards ( Fig. 9c ), dorsum with a pair of denticles ( Fig. 9b ), subpetiolar process broader anteriorly with an acute projection. Postpetiole wider andlonger than petiole ( Fig. 9c ), with a pair of spines broader than spines of petiole and curved anteriorly, dorsum of postpetiole with a transversal elevation ( Fig. 9c ), subpostpetiolar process pronounced and compressed anteroposteriorly ( Fig. 9b ).

Gaster elongate, protruding anteriorly, without anterior lamellae or carinae ( Fig. 9c ).

Gyne measurements (N=2): HL 1.32-1.40; HW 1.28-1.38; EL 0.32- 0.35; PW 1.38-1.43; WL 1.85-1.88; PTL 0.33-0.34; PTW 0.48-0.50; PPL 0.35-0.38; PPW 0.63; GL 2.31-2.40; HBL 0.46-0.50; HBW 0.12; TL 6.20-6.36; CI 96.6-98.2; OI 25.1-25.4; PI 65-7.58; HBI 24.0-26.1.

Gyne description: Body black; head predominantly black, with the edges of dorsum and part of lateral face yellowish. Apices of femora, tarsi and external face of tibiae yellowish. First gastral tergite with an anterior and a posterior pair of yellowish spots, each one occupying about one fifth of the first tergite length; posterior margins of each tergite and sternite yellowish ( Fig. 10 ).

Sculpturing and pilosity as in the soldiers, except by some erect hairs on mesoscutum and first tergite of gaster.

Head as in the soldier (CI 96.6-98.2), but with frontal carinae convergingposteriorly ( Fig. 10a ).

Indorsalview, anteriormarginofpronotumslightlyrounded, narrower than in the soldiers, lateral margins with a pair of denticles pointed forwards, pronotal carina weakly developed ( Fig. 10b ). Dorsally, mesoscutumsubtriangular, anteriormargin rounded; notauli absent; parapsidiallinesfeeblyvisibleand parallel; transscutal line weakly impressed, reaching the lateral margins of mesosoma; scutoscutellar groove weakly impressed, arched; scutellum well delimited and broader anteriorly; axillae rounded posteriorly ( Fig. 10c ). Laterally, mesopleural groove dividing anepisternum and katepisternum; metapleura divided in upper metapleura and lower metapleura by a groove; metapleuropropodeal groove not impressed ( Fig. 10b ). In dorsal view, posterior margin of propodeum concave, with a pair of denticles ( Fig. 10b ). Wings as in genus description.

Petiole and postpetiole as in the soldier, but longer ( Fig. 10b, c ).

Gaster elongated, protruding anteriorly, without anterior lamellae or carinae ( Fig. 10c ).

Comments: This species differs from C. marycorn new species and C. monicaulyssea new species by the anterior portion of the first tergite of gaster, near of the postpetiolar insertion, not striate, while the two first species present short striae in this portion. Also, the first gastral tergite in C. gabicamacho is covered by appressed canaliculate hairs anteriorly and posteriorly, with a narrow central portion with appressed simple hairs, while C. marycorn newspecies has appressed canaliculatehairs only laterally onanterior portion and posterioredges of tergite, the central portion has sparse appressed simple hairs, and C. monicaulyssea new species has abundant appressed canaliculate hairs evenly distributedover the tergite. Cephalotes gabicamacho is the species C.sp. 3 in the molecular phylogeniesof Price et al. (2014, 2016), where it is placed as sister to the clade containing all other members of the angustus , fiebrigi and prodigious groups and thus contributes to the paraphyly of theangustus group ( Fig. 54 ).

Natural history: This specieswas collected in two cities of state of Minas Gerais, both in the core region of the Brazilian biome Cerrado, a savanna physiognomy. In Paraopeba, asingle worker was collected in an arboreal pitfall trap, in a Cerrado area, at 750m a.s.l. In Uberlândia, the specimens werecollected in twopoints at the Private Natural Heritage Reserve of Clube Caça e Pesca Itororó. This reserve is a 640 ha area, with Cerrado sensu strictu as predominant vegetation. This Cerrado physiognomy is characterized by tree canopies approximately 3-6 m high, annual average temperature between 18 and 24°C, and altitude 850 m a.s.l. Annual average precipitation is 1,700 mm, with two welldefined seasons, rainy summer (October to March) and dry winter (April to September) (Pinese et al., 2015). The coloniesfrom the Reserve of Clube Caça e Pesca Itororó were discovered in April 2005 (paratype C05-134) and July 2006 (holotype C06-94), respectively, as part of a larger survey of Cephalotes diversity at the reserve (see Powell, 2008, 2016). In both cases, discovery occurred during a transect baiting approach, designed to maximize the discovery of Cephalotes forager recruitment (See Powell, 2008 for explanation). For each colony, all occupied nests were located using dense baiting within the home tree and visually tracking recruits back to their nest (following methods of Powell, 2009). Collections were made by sealing each nest in the early morning, when foragers are not active, and then removing the intact branches for dissection in the laboratory (following methods of Powell, 2009). The colonies occupiedsix and eleven nests, respectively. The two colonies occupied different tree species, indicating no tree species preference. Nevertheless, nest entrance size was limited to sizes that closely fit a single soldier head (see data for C. sp 3 in Powell, 2016), characteristic of species with adisc-headed soldier morphology (Powell etal., 2020).

Distribution: Minas Gerais, Brazil.

Etymology: This speciesis named, inapposition, after the Brazilian myrmecologist Gabriela Procópio Camacho,for herimportant contribution to our current knowledge on Hymenoptera evolution, especially Ectatommine ants. Gabriela is a close friend of the three authors and her work and career trajectory have provided personal inspiration, as well as inspiring many other female myrmecologists.

Figures

Figure 4 Workers of angustus group. A: C. notatus. B and H: C. goeldii [H: CASENT0922535]. C: C. adolphi [CASENT0904906]. D and I: C. targionii [D: CASENT0173661, I: CASENT0922537]. E and M: C. angustus [E: CASENT0909277]. F: C. frigidus. G and J: C. conspersus [J: CASENT0922530]. K and N: C. monicaulyssea. L: C. gabicamacho. O: C. pallidicephalus. P: C. marycorn.

Figure 8 Worker of Cephalotes gabicamacho. A: frontal view. B:lateral view.C: dorsal view. Brazil:MG, Uberlândia.

Figure 9 Soldier of Cephalotes gabicamacho. A: frontal view. B: lateral view. C: dorsal view. Brazil: MG, Uberlândia.

Figure 10 Gyne of Cephalotes gabicamacho. A: frontal view. B: lateral view. C: dorsal view. Brazil:MG, Uberlândia.

Figure54 Themaximum cladecredibility treefrom phylogenetic analysesperformed byPriceet al.(2016) basedonmorphologicalandmoleculardata.The tree has beentrimmedtoinclude onlythose species knownfromBrazil.Thelabelsforthespecies groupsfollowour proposals,including thesynonymies,andtheprevious namesforthesynonymized groupsareshown ingrey.