Blepharidatta delabiei, Brandão, Carlos Roberto F., Feitosa, Rodrigo M. & Diniz, Jorge L. M., 2015

Brandão, Carlos Roberto F., Feitosa, Rodrigo M. & Diniz, Jorge L. M., 2015, Taxonomic revision of the Neotropical Myrmicinae ant genus Blepharidatta Wheeler, Zootaxa 4012 (1) : 49-52

Blepharidatta delabiei new species

( Figs 1 E – F, 2 G – H, 3 E – F, 4 E – F, 8 A – I, 9)

Blepharidatta sp. Kempf, 1975: 370–371, males. Figs 19–22. Brazil.

Holotype worker: BRAZIL: Bahia: Una ( Res. Biol . IBDF), 25.ix.1988, J.L.M. Diniz col. # 2373 –6 JLMD collection [ MZSP] .

Holotype measurements: HL 0.8; HW 0.6; SL 0.6; ML 0,25; WL 0.8; PL 0.45; Ppl 0.2; Hfl 0.7; GL 0.8.

Paratypes: 20 workers, one gyne and two and males, same data as Holotype (6 workers, one male and one gyne [ MZSP] , 3 workers, one male [ HCJG] , 3 workers [ CPDC] , 4 workers [ DZUP] , 3 workers [ MCZC] , 3 workers [ USNM] , one worker [ INPA]) .

Diagnosis (worker). Comparatively small species. Body predominantly chestnut. Head and mesosoma entirely covered by longitudinal to subconcentric thick rugae; in frontal view, anterior face of pronotum almost vertical and densely covered by a row of short longitudinal rugae. Eye rounded and strongly protruding. Propodeal spine shorter than petiole, in lateral view. Petiolar node dorsally rounded in lateral view.

Worker measurements (n=4): HL 0.8–0.85; HW 0.55–0.7; SL 0.55–0.7; ML 0.25; WL 0.8–0.9; PL 0.45–0.6; Ppl 0.2–0.25; Hfl 0.7–0.8; GL 0.8–1.25.

Worker description ( Figs 1 E – F). Color predominantly chestnut, with slightly lighter head and gaster; appendages yellowish-brown. Head and mesosoma entirely covered by vermiculate and predominantly longitudinal thick rugae; gaster mostly smooth. Mandible with short fine longitudinal striae covering the anterior third of blade. Clypeus mostly smooth, with a few irregular longitudinal striae on central disc. Antennal scrobe almost entirely smooth and shiny, especially at the central portion, with a few transverse curved striae near the antennal insertion and at the apex. Dorsal surface of head with 10 to 12 prominent longitudinal subparallel rugae, extending from posterior margin of clypeus and becoming gradually divergent and concentric towards the posterior margin of head. In lateral view area between ventral margin of scrobe and ventral margin of head covered by polygonal cells formed by irregular rugulation. Ventral face of head smooth and shiny. Mesosoma entirely sculptured with irregular longitudinal rugae intercalated by transverse thick carinae, which are covered by weak areolae; dorsum covered by four to ten almost perfectly concentric rugae, forming a conspicuous and irregular circular pattern. In full frontal view anterior portion of pronotum elevated, permitting view of 10 short vertical rugae; anterior portion of pronotum separated from the rest of mesosoma by a strongly elevated carina, better seen in lateral view; lateral faces of pronotum weakly and irregularly rugulose. Meso- and metapleuron longitudinally rugose. Petiole with four to six longitudinal rugae in lateral and in dorsal view. Postpetiole weakly sculptured, with faint longitudinal rugulae over an areolate surface. Gaster almost entirely smooth and shining, with feeble isolated areolate sculpture near insertion of postpetiole. Appendages entirely but weakly areolate.

In general, body covered by sparse, cream colored hairs; hairs stiff, long, slightly curved, uniform in width, and truncate. Anterior margin of clypeus with a row of hairs gradually increasing in length from lateral portions to center. Dorsum of mandible with subdecumbent flexuous hairs restricted to the lateral border. Frontal carina with about five regularly spaced and upwards bent hairs. Pilosity on mesosoma sparse, moderately abundant dorsally. Dorsum of petiole and postpetiole covered by sparse paired hairs; ventral face of postpetiole with a single pair of hairs. Gaster entirely covered by regularly spaced hairs. Appendages covered by short, subdecumbent to appressed hairs.

In frontal view, head subtriangular, with lateral margins gently converging towards mandible. Posterior margin of head straight, with strongly expanded, auriculate occipital corners, rounded to acute apically. Anterior margin of clypeus somewhat irregular and slightly convex; central disc feebly concave to flat. Antennal scrobe considerably deep and wide, able to receive the whole scape at rest; frontal carina partially covers the scrobe in frontal view, proximal half of scrobe exposed. Bulging compound eye with about six to seven facets along maximum diameter. Ventral cephalic surface separated from side by strong carina, better seen in lateral view.

Dorsal outline of mesosoma irregularly continuous and weakly convex in lateral view. Promesonotum slightly convex medially in frontal view, gently descending towards humeral corners; anterior face of pronotum vertical in profile, separated from dorsal face by a conspicuous angle; dorsum of promesonotum elevated slightly to well above the level of propodeum; pronotal humeral corner rounded to weakly angulate in dorsal view; anteroventral corner with well-developed anteriorly directed spine. Metanotal groove shallowly impressed to well-marked, clearly visible in lateral view; mesometapleural suture faintly marked to absent, not clearly separating meso- and metapleuron. Dorsal profile of propodeum extremely short and straight; propodeal spines as long as the petiolar peduncle in lateral view and strongly divergent in dorsal view; infraspinal lamella present, fused to the propodeal lobe; propodeal lobe subquadrate in side view, its length half that of propodeal spine.

Petiole strongly pedunculate, node moderately elevated and considerably elongate, anterior face weakly sloped and posterior face almost vertical in lateral view; petiolar peduncle with discrete anteroventral process directed anteriorly. Postpetiole distinctly convex dorsally and about three times shorter than petiole, without ventral processes. Gaster suboval, tergum I anterolaterally discretely angular in dorsal view.

Sting apparatus ( Figs 8 A – I). Spiracular plate ventral tubercle absent. Quadrate plate apodeme area smaller than plate body. Anal plate as in other Blepharidatta species. Oblong plate with long posterior apodeme, as long as the triangular plate. Subterminal tubercle present. Gonostylus membranaceous terminal band present and short.

Triangular plate dorsal tubercle prominent; median tubercle absent. Lancets as in other Blepharidatta species. Sting antero-ventral processes absent. Sting reduction index 31–41. Furcula dorsal length equal to lateral arms.

Gyne measurements (n=1): HL 0.85; HW 0.65; SL 0.6; ML 0.25; WL 0.95; PL 0.65; Ppl 0.25; Hfl 0.75; GL 1.25.

Gyne (ergatoid) description ( Figs. 2 G – H). Similar to conspecific worker except for the presence of three ocelli triangularly placed on frons and the more robust gaster. No evidence of wing buds on mesosoma.

Male measurements (n=1): HL 0.55; HW 0.4; SL 0.15; ML 0.15; WL 0.95; PL 0.65; Ppl 0.25; Hfl 0.75; GL 1.25.

Male description (Figs 3 E – F). Body dark-brown, with head, pronotum, anterior portion of petiolar peduncle, and first third of gaster slightly lighter; head with a blackish rounded area on cephalic disc; appendages yellowish. Body densely areolate with few irregular striae, especially on head dorsum and sides of mesosoma. Gaster smooth and shiny, without sculpture. Long, subdecumbent, cream-colored hairs sparsely covering head and mesosomal dorsum; metasoma virtually glabrous, with few sparse hairs on the apical segments of gaster; appendages with fine and sparse appressed hairs.

Head subrectangular, longer than wide. Mandible short and subfalcate, with vestigial denticles on masticatory margin; scape not reaching posterior margin of eye in frontal view; pedicel enlarged and relatively short; first funicular segment almost twice longer than the pedicel. Eye huge and extremely protruding, occupying about three fourths of head in lateral view. Ocelli present and equally developed.

Pronotum reduced in dorsal view, with discrete and rounded humeral angles; scutum large, rounded anteriorly and with a slightly convex posterior margin; notauli weakly distinct. Prescutellum narrow; scutellum wider than long. Metanotal suture well-marked and shallow. Propodeum unarmed, strongly rounded in profile, with a short dorsal profile and almost vertical declivous margin; propodeal spiracle small and distant from the declivous margin; propodeal lobe vestigial. Legs more elongate than in conspecific females.

Wings dark amber and covered by a dense pubescence (Fig. 3 E – F); venation reduced and entirely nebular; pterostigma absent; longitudinal veins Sc+R, Rs, M, Cu, and A present; cells C, R and SR closed. Hind wing with R cell only; four sub-median hamuli present.

Petiole pedunculate, node strongly rounded; ventral processes absent. Postpetiole subrectangular in dorsal view, longer than broad, and attached to gaster by almost its full width. Gaster elongate, with rounded gastral shoulder.

Larva. Unknown.

Etymology. This species is named for our friend Dr. Jacques H. C. Delabie, in recognition of his many years of devoted work on the ants of Bahia, Brazil and for his valuable support during the elaboration of this work.

Comments. The very particular sculpture pattern readily separates this species from its congeners. All other species in the genus present sparse and predominantly chaotic rugulation over the body. In B. delabiei the rugae are thicker, denser and more regular. An interesting morphological variation can be observed among different populations of this species: most specimens present the head and mesosomal dorsum covered by longitudinally oriented rugae, while a few individuals display a subconcentric rugulation pattern. Considering the differences observed of the overall sculpturing pattern in other Blepharidatta species, and since intermediate forms can be found, we refrain from separating the material into distinct species.

Workers of this species are known only from the Atlantic Forest of southern Bahia state, frequently collected in leaf litter samples. Kempf (1975) described four males from Pedra Azul, northeastern Minas Gerais state, not accompanied by workers or gynes. Although he believed these specimens probably represented males of B. brasiliensis , he refrained from identifying them as such and described them as Blepharidatta sp. Diniz and Brandão briefly visited this locality twice but were not able to find more specimens. A fifth male collected in Itambé, Bahia in 2003 solved the matter, as it is identical to those described by Kempf from Pedra Azul.

Material examined: BRAZIL: Bahia: Aurelino Leal , 14o19’52”S 39º21’32”W, 14.iv.1997, J.R.M. Santos, 1 worker ( MZSP) ; Ilhéus, Banco de Pedra 14º40’51”S 39º15’24”W ( Mata W-A23 ) 12.i.1998, J.R.M. Santos & J.C.S. do Carmo, 2 workers ( MZSP) ; Ilhéus, Castelo Novo , 14º39’S 19º11’W, 30.ix – 4.x.2002, P.R. Santos & J.R. Santos, 3 workers ( CPDC) ; same data, 24.iv.2000 ( Mata – A24 ), J.R.M. Santos, 3 workers ( MZSP) ; Ilhéus, Águas de Olivença, 19o0 0 50’S 39 o0 1 91’W (sic), J.R.M. Santos, 4 workers (2 CPDC, 2 MZSP) ; Ilhéus, Pimenteira , 14º32’72”S 39º25’39”W (sic), 06.x.1997, J.R.M. Santos & J.C.S. do Carmo, 6 workers (3 DZUP, 3 MZSP) ; Itambé, NENA , 15o23’23”S 40º49’33”W, 20.vii.2003, J.C.S. do Carmo, 4 workers, 1 male ( MZSP) ; L. Encantada , 9.i.1994, J.H.C. Delabie # 4756 , 6 workers (3 CPDC, 3 MZSP) ; Serro Grande – Uruçuca , 2.xii.1993, J. Jardim # 4731 , 3 workers ( MZSP) ; Una, 16.iii.1994, Jomar , # 4822 , 3 workers ( DZUP) ; Una. Res. Ecológica IBDF, xi.1987, C. Alves #206, 1 worker; Una (A45 ) 15º11’04”S 39º00’56”W, J.R.M. Santos, 6 workers ( CPDC) ; same data 29.xi.1988, J.L.M. Diniz # 2373 –2376, 18 workers (holotype and paratypes); Mascote , 153349S 0391834W, 18.vi.1999, J.R.M. Santos col., 2 workers ( CPDC) . Minas Gerais: Pedra Azul, xii. 1972, 800 m, Seabra & Alvarenga ( Kempf coll. 8828 ) 3 males; same data, i.1971, F.M. Oliveira, 1 male ( MZSP) .