Cephalotes liviaprado, 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 : 29-30

Cephalotes liviaprado new species

urn:lsid:zoobank.org:act:DDC94CF2-2BA3-4506-9F53-65F557099606 Figs. 29 a-c, 30a-c, 32

Holotype: BRAZIL, MS, Porto Murtinho , 28.i.2015 (dique, espinho P. ruscifolia), P. R. Souza, DZUP 550171 (worker) [ DZUP].

Paratypes: samedataas holotype: DZUP 550173 (2 workers, 1 soldier), DZUP 550172 (1 worker, 1 soldier) [ DZUP], DZUP 550174 (2 workers, 1 soldier) [ MZSP], DZUP 550175 (1 worker, 1 soldier) [ INPA ].

Diagnosis: Amember offiebrigi species group. Workers withlong flexuous hairs ( Fig. 29b ). In frontal view, frontal carinae with a lateral projection anteriorly to the eyes ( Fig. 27d ). In soldier, first gastraltergite, with erect hairs, few and sparse appressedhairs can be present ( Fig. 30 ).

Worker measurements (N=7): HL 1.08-1.23; HW 1.18-1.33; EL 0.32-0.38; PW 1.10-1.25; WL 1.21-1.34; PTL 0.26-0.29; PTW 0.62-0.64; PPL 0.26-0.31; PPW 0.66-0.75; GL 1.50-1.80; HBL 0.41-0.48; HBW 0.13- 0.14; TL 4.36-4.92; CI 104-109; OI 26.4-29.8; PI 37.5-44.3; HBI 27.2-30.8.

Worker description: Body black; frontal lobes, mandibles, and apices of each segment of legs brownish to ferruginous ( Fig. 29 ).

Mandibles, dorsum of head, mesosoma, petiole and postpetiole foveate-rugose, space between foveae microalveolate ( Fig. 29a, c ). Frontal lobes weakly striate ( Fig. 29a ); ventral face of head and lateral of mesosoma areolate-rugose; rugosities of dorsum of mesosoma extending to the middle of propodeum declivous face, lower portion of propodeum microalveolate. Legs microalveolate, except by tibiae, which external face is areolate-rugose. Gaster microalveolate, the anterior half of first tergite with short longitudinal striae originating near the postpetiole insertion ( Fig. 29c ); first sternite laterally with some irregular weak rugosities.

Body with abundant flexuous hairs, and some sparse appressed canaliculate hairs.Anterior margin of clypeus with suberect canaliculate hairs ( Fig. 29a ).

Head slightly wider thanlong (CI 104-109), dorsum weakly convex ( Fig. 29b ). Mandibles with a weakly developed lateral angle. Anterior margin of clypeus slightly concave, with a pair of lateral denticles. Frontal carinae notched anteriorly to the eyes, forming a lateral angle ( Fig. 29a ). Antennalclubill-defined. Lateroventralmarginsofhead without carinae. Vertexal corners with irregular lamellar expansions ( Fig. 29a ).

Mesosoma stronglyconvex in lateral view ( Fig.29b ). In dorsal view, lateral margins of pronotum with three pairs of denticles, the anterior one acute and the two posterior obtuse; promesonotal groove absent ( Fig. 29c ). Mesonotum with a pair of short blunt denticles. Propodeal grooveabsent.Dorsal and declivousfacesof propodeum continuous, not meeting in a distinct propodeal angle; lateral margins of propodeum with an anterior pair of short blunt denticles, followed by a pair of large and acuteand a rowof minor acutedenticlesnear petiolarinsertion, the number and degree of development of the denticlesvary even between sides of the samespecimen ( Fig.29c ). Femoranotangulated dorsally, mid andhindbasitarsi notflattened, with subparalleldorsalandventral faces.

Indorsalview, petiolecompressedanteroposteriorly, indorsal view, anterior margin with a discrete median concavity, lateral spines curved backwards, dorsum with a pair of denticles ( Fig. 29b ), subpetiolar process acute anteriorly ( Fig. 29b ). Postpetiole slightly longer than petiole, without dorsal projections, lateral spines broad and curved backwards ( Fig. 29c ), subpostpetiolar process pronounced and compressed anteroposteriorly ( Fig. 29b ).

Gaster oval, with a pair of well-developed thick opaque anterior expansions, not extending posteriorly formingalateral lamella ( Fig.29c ).

Soldiermeasurements (N=4):HL 1.96-2.09;HW1.82-1.96;EL 0.40-0.43; PW 1.75-1.94;WL 1.66-1.88;PTL 0.32-0.38;PTW 0.85-0.89;PPL 0.33-0.39; PPW 0.88-0.90;GL 2.04-2.40; HBL 0.44-0.48;HBW 0.14-0.15;TL 6.31-7.13; CI 89.6-94.9; OI 21.3-21.2; PI 37.6-42.2; HBI 29.9-33.3.

Soldier description: Body black; frontal lobes and apices of each segment of legs brownish to ferruginous ( Fig. 30 ).

Mandible,ventralfaceofhead( Fig.30a ), promesonotumandmesonotum foveate,spacebetween foveaemicroalveolatetosmooth ( Fig.30c ). Dorsum of head with small foveae anteriorly, increasing in diameter posteriorly. Dorsal face of propodeum, petiole andpostpetiole foveate, without space betweenfoveae; declivousface of propodeum microalveolate, withsome striae on upper surface; lateral of mesosoma areolate-rugose ( Fig. 30b ). Legs microalveolate, except tibiae which external face is areolate-rugose. Gastermicroalveolate,withafewshortweaklymarkedlongitudinalstriae, originating near the postpetiole insertion ( Fig. 30c ).

Body with abundant flexuous hairs ( Fig. 30b ), except on dorsum of head, whichhastinysuberectsimplehairs( Fig.30a ).Mandibles,lateraland ventralfaceofhead,meso- andmetapleurawithfewappressedcanaliculate hairs. Anterior margin of clypeus with suberect canaliculate hairs. Gaster with sparse appressed simple hairs ( Fig. 30b, c ).

Head longer than wide (CI 89.6-94.9). Mandibles with a strong longitudinallateralangle.Clypeuswithapairofdenticles ( Fig.30a ).Dorsum of head disc shaped, convex medially ( Fig. 30a ). Frontal carinae crenulate convergingposteriorly.Antennalclubill-defined.Roofof antennal scrobes withlateralcarinaeand aposteriordenticle.Lateroventralmarginsofhead without carinae. Vertexal corners forming pointed projections separated of the dorsum cephalic disc ( Fig. 30a, b ).

In lateral view, pronotum ascending, pronotal carina weakly marked and crenulate ( Fig. 30b, c ). In dorsal view, anterior margin of pronotum rounded,lateralmarginswithtwopairsof denticles,theanteriorlyoneacute, theposterior oneobtuse.Mesonotumandpropodeumcontinuousand flat ( Fig.30b ); mesonotumwithapairofbluntroundedprojections;propodeal groove impressed; dorsal and declivous faces of propodeum meeting in a distinct propodeal angle, in dorsal view, lateral margins of propodeum withapairofmedianobtusedenticlesand apairof well-developedspines, directed upwards ( Fig.30c ). Legs as in the worker.

Petiole and postpetiole as in the worker.

Gasterelongate,withtheanterolateralexpansionsprotrudinganteriorly ( Fig. 30c ).

Comments: Thisspeciesissimilar toC. pilosus butcanbe distinguished by the frontal carinae notched anterior to the eyes, forming a lateral angle and by the less abundant and shorter pilosity; in C. pilosus the frontal carinae is evenly straight to slightly depressed anterior to the eyes, but neverforming a lateral angle andthe pilosity is long anddense.

Natural history: Cephalotes liviaprado was collected in the Chaco formation. This ecosystem is part of the diagonal zone of seasonallydry open areas in South America. The so called “Gran Chaco ” occurs in northern Argentina, western Paraguay, southeastern Bolivia, and the extreme western of Mato Grosso do Sul state in Brazil, exclusively in the city Porto Murtinho (Prado, 1993). The vegetation is represented by shrub, deciduous, and spinous vegetation, usually associated with saline soils (Silvaet al., 2000). The Chaco extends from tropicallatitudes (18° S) tosubtropical zones (31° S), and theclimate is marked by strong seasonality, with more severe summers, and winter frosts (Werneck, 2011). The Brazilian Chaco (Chacosensu stricto) occupy a subregion of the Pantanalbiome, and extends over about 7% of itsterritory (Silva et al., 2000). Despite its relatively small area in Brazil, this formation is considered of highpriority forconservation (Tálamo and Caziani, 2003). However, the anthropic use in this area for agricultureand logging has been a serious threat for the maintenance of this ecosystem and the species that live in it (Pott and Pott, 2003).

Cephalotes liviaprado was collected in the thorns of the tree species Prosopis ruscifolia Griseb. (Fabacea: Mimosoideae), which is endemic to the Chaco (Fuster, 2012). This tree species is adapted to edaphic conditions, and marshy and salty environments, and is known as a pioneer and colonizer plant. It has large stem thorns (10 to 30 length and 2 cmdiameter) and extrafloral nectaries (Vilela and Palacios, 1997) which favors nesting by arboreal ants, like Cephalotes (Fuster, 2012) . So far, C. liviaprado has been collected only in this location exclusively associated with P. ruscifolia. If these species areintimately relatedand endemic of Chaco, they must be extremely threatened.

Distribution: Mato Grosso do Sul, Brazil.

Etymology: The specific epithet, in apposition, is in honor of Livia Pires do Prado, a Brazilian myrmecologist and passionate historian of science, for hercontributions to thetaxonomy of Brazilian ants and the rescue of extremely relevant names and facts involving the history of Brazilian entomologists of all generations. Her work and dedication to science stands as aninspiration to female myrmecologists and students of the history of science alike.

Figures

Figure 27 Workers of fiebrigi group.A:C.quadratus. B, G and I: C.specularis. C:C.complanatus (basalis group).D and J:C.liviaprado. E:C. pilosus [CASENT0904912].F: C.basalis (basalis group). H: C. guayaki [CASENT0173677]. K:C.fiebrigi [CASENT0922539]. L: C. jheringi.

Figure 29 Worker of Cephalotes liviaprado. A: frontal view. B: lateral view. C: dorsal view. Brazil: MS, Porto Murtinho.

Figure 30 Soldier of Cephalotes liviaprado. A: frontal view. B: lateral view. C: dorsal view. Brazil: MS, Porto Murtinho.