Typhlomyrmex meire, Lacau, S., Villemant, C. & Delabie, J. H. C., 2004

Lacau, S., Villemant, C. & Delabie, J. H. C., 2004, Typhlomyrmex meire, a remarkable new species endemic to Southern Bahia, Brazil (Formicidae: Ectatomminae)., Zootaxa 678, pp. 1-23 : 5-16

Typhlomyrmex meire Lacau, Villemant & Delabie, new species

(Plates 1-5)

Type Material. Holotype worker from Brazil, labeled: " Bahia state, Ilheus, Fazenda Recreio, alt. 36 m , 14°45'21"S - 39°13'34"W, 14.vi.2002, S. Lacau & B. Jahyny coll.", in [ CPCC]. Paratypes: 61 nidoparatypical specimens (21 workers, 27 winged queens and 13 males), same data as the holotype, 9 workers, 15 winged queens and 4 males in [ CPCC]; 5 workers, 5 winged queens and 2 males in [ MZUSP]; 1 worker, 1 winged queen and 1 male in [ MPEG]; 1 worker, 1 winged queen and 1 male in [ INPA]; 1 worker, 1 winged queen and 1 male in [ MNHN]; 1 worker, 1 winged queen and 1 male in [ BMNH]; 1 worker, 1 winged queen and 1 male in [ LACM]; 1 worker, 1 winged queen and 1 male in [ AMNH]; 1 worker, 1 winged queen and 1 male in [ MCZC].

Other material examined: 4 workers and 1 winged queen, Brazil, Bahia, Ilheus, Area da Zoologia, CEPEC, alt. 15 m , 14°15'S - 39°13'W, x.1986, J.H.C. Delabie coll. in [ CPCC] ; 1 worker, Brazil, Bahia, Ilheus , 1986- 1987, J.H.C. Delabie coll., N°42 in [ CPCC] ; 1 winged queen, Brazil, Bahia, Ilheus, CEPEC , 21.v.1987, P. Terra coll., N°4587 in [ CPCC] ; 1 male, Brazil, Bahia, Ilheus, CEPEC , 29.ix.1987, P. Terra coll., N°4587 in [ CPCC] ; 1 male, Brazil, Bahia, Ilheus, CEPEC , 03.v.1988, P. Terra coll., N°4587 in [ CPCC] ; 2 queens winged, Brazil, Bahia, Ilheus, CEPEC, Q. G' , 08.iii.1991, M. R. Smith coll. in [ CPCC] ; 1 worker and 1 winged queen, Brazil, Bahia, Ilheus, CEPEC, Q. G' , 08.vii.1992, J. C. Soares do Carmo coll. in [ CPCC] ; 1 worker, Brazil, Bahia, Ilheus, CEPEC/CEPLAC, Q. G' , 21.vii.1992, J.C. Soares do Carmo coll. in [ CPCC] ; 1 worker, 1 winged queen, 1 male, Brazil, Bahia, Ilheus, CEPEC , 03.x.1995, J. Assis coll. in [ CPCC] ; 1 dealate queen, Brazil, Bahia, near Una, 260 II CO 22 , projeto RestaUna coll. in [ CPCC] ; 1 worker, Brazil, Bahia, Canavieiras, Oiticica , 14°24'43"S - 39°01'00'W, 30.iii.1998, J. R. M. Santos coll. in [ CPCC] .

Etymology. Named in honor of Mrs. Lucimeire de Souza Ramos Lacau.

Diagnosis. Medium-sized species, easily identified by the following characters: worker and queen both with 10-segmented antennae, including a 2-segmented apical club; male with 12 segmented antennae; queen and worker with subtriangular mandibles, bearing5 to 7 large teeth varying in size and bluntness among individuals of the same colony; anterior face of the clypeal dome vertical in females.

Worker (Plate 1).

Measurements (mm) and indices: data for holotype given in [brackets]; means with standard deviations for paratypes (n=10) given in (parenthesis); maximum range for paratypes (n=10) given in {}: CivW [0.42] (0.44±0.02) {0.41-0.46}; DPeW [0.25] (0.24±0.01) {0.24-0.26}; HeW [0.17] (0.17±0) {0.17-0.18}; HL [0.52] (0.54±0.01) {0.52-0.56}; HW [0.50] (0.5±0.02) {0.47-0.53}; ML [0.33] (0.33±0.02) {0.28-0.37}; SL [0.33] (0.33±0.02) {0.32-0.36}; PW [0.35] (0.35±0.01) {0.33-0.38}; PeL (0.23±0.01) {0.21-0.24}; WL [0.73] (0.75±0.01) {0.72-0.77}; CI [96.4] (93.9±1.8) {90.9-96.4}; MI [63.6] (61±4.69) {58.3-69.6}; PrI [69.81] (69.65±2.94) {64.29-75.47}; SI1 [66] (68.68±4.07) {62.5-76}; SI2 [63.6] (62.54±3.13) {58.3-69.1}.

Head: subquadrate, weakly elongated; holotype CI 96.4; average CI 94.1 (n= 11, holotype+ 10 paratypes); CI range 90.9-96.4; head distinctly wider than alitrunk; average PrI 69.65 (n=10 paratypes); range PrI 64.29-75.47; maximal head width occurs at 2/3 distance from anterior clypeal margin to vertexal margin; vertexal margin weakly concave; posterolateral corners rounded; sides of head weakly convex and slightly converging anteriorly; clypeus medially dome-shaped, the dome conspicuously protruding from the lateral clypeal margins and with a vertical anterior face; clypeal margin medially convex and partially concealed by the dome in dorsal view; anterior clypeal lamella narrow, without a medial lobe; tentorial pits well separated from toruli and located in a weakly impressed depression at the basal clypeal margin; eyes minute with 4 or 5 poorly defined ommatidia situated just before the middle of the capsule sides; frontal lobes well developed, weakly inclined, close together, but conspicuously separated by a short frontal groove limited anteriorly by the clypeal dome and posteriorly by the convergence of frontal striae and rugosities; antennal sockets partially concealed by the frontal lobes frontal carinae slightly diverging and softening posteriorly; toruli circular and definitely separated, visible by transparency through the frontal groove integument, their internal rim rising and fused with frontal lobes base; antenna 10-segmented; scape robust, as wide as the pedicel length, and lacking a longitudinal carina at its anterior margin; it appears conspicuously bent ventrally at one third of its length in frontal view and is sharply enlarged at its midlength in dorsal view, the maximal width being more or less equal to the pedicel length; when folded backward, its apex does not reach the vertexal margin; pedicel about twice as long as wide, and about as long as the 3 following segments together; segments A3-A8 much wider than long; segment 3 longer than each one of the 5 following segments; segment 9 much wider at its base than segment 8 in dorsal view, and forming with segment 10 a club conspicuously larger than the rest of funicle; segment 10 approximately 3.5 times longer than segment8, and about 3 times longer than segment 9; apical club approximately 1.5 times longer than segments 3 to 8 together; mandible shape elongated-subtriangular, the apical margin joining basal margin at an obtuse angle; mandibles ventrally curved, crossed when closed, their basal margins weakly convex and not reaching the anterior clypeal margin; outer margin of mandible almost straight basally and curved at the level of apical tooth; masticatory margin toothed from base to apex as follows: four or five large teeth of increasing size, more or less spaced and variably shaped, often large and blunted (occasionally flattened), but sometimes small and acute, as well as an elongate apical tooth; mandible falciform and more or less acute while strongly enlarged basally; maxillary and labial palps 1-segmented (2 specimens dissected); hypostomal bridge well developed, its extremities greatly enlarged and ending in a small rounded tooth which weakly emerges under the base of the mandible; genal bridge distinct, its extremities enlarged and in contact with the hypostomal bridge; occipital carina lacking.

Mesosoma: sub-rectangular in lateral view; pronotum anteriorly rounded in dorsal view, a little wider than long, and strongly sloping anteriorly in lateral view, its posterior part horizontal; promesonotal suture underlined by a weak furrow, forming an arch widely concave posteriorly; mesonotum almost flat dorsally; ventral parts of anterior and posterior margins of mesopleura straight and dorsal parts inclined; mesothoracic spiracle very small and partially concealed; metanotal groove distinct but weak; sides of the propodeum weakly converging posteriorly in dorsal view; meso-metapleural suture almost straight, underlined by a narrow groove bordered laterally by two thin carinae; metapleural gland orifice in profile as a short oblique slit, bounded below by a convex rim of cuticle that directs the orifice posterodorsally; the swollen bulla of the gland is visible by transparency through the integument, its anterior margin placed slightly before the propodeal spiracle; dorsal face of the propodeum weakly inclined and almost flat, gradually rounding beyond the spiracle towards the sloping posterior face; propodeal spiracle opened laterally and slightly downward, its large and somewhat elliptic orifice bordered by a thin cuticular ring; propodeal lobes lacking; dorsal margin of the propodeal foramen surrounded by a strong horizontal crest preceded by a narrow horizontal groove. Pro- and mesothoracic legs slightly shorter and more robust than the metathoracic legs; femora ventrally thickened, with the distal half of their ventral face weakly concave and sometimes bordered posteriorly by a discrete carina; pro- and metafemora conspicuously compressed basally, their axes bent forward and backward respectively; tibial spurs 1, 1, 1; meso- and metatibial spurs simple, very small and barely visible; strigile curved and enlarged basally; probasitarsus curved, slightly longer than two thirds of the protibia length; mesotibia and metabasitarsus about 3 times longer than the mesobasitarsus, and metatibia about 2 times longer than the metabasitarsus; protarsal claws acute, with a small tooth behind the apical point; meso- and metatarsal claws acute and simple; arolia small.

Metasoma: petiole short, weakly pedunculate and broadly constricted between abdominal pre- and postsegment; the posterior foramen of the postsclerite higher than the anterior foramen of the presclerite in relation to the horizontal body axis; petiolar node broad, scale shaped and strongly rounded apically with a very short and almost flat posterior face; anterior face of node weakly concave basally and its posterior half vertical; anterodorsal margin rounded; dorsal face of node sub-rectangular to trapezoidal with well rounded angles in dorsal view; node about 1.5 times wider than long, its lateral faces convex and slightly converging forward in dorsal view; spiracles on lateral protuberances near anterolateral base of node, their orifices circular, opening laterally and slightly posteriorly; laterosclerite lacking, the tergite and sternite fused but the suture visible over its entire length, opened posteriorly where the tergal crests of the helcium fit; node narrowed ventrally as on fig. G of Plate 1; sternite with a short medial carina lengthened anteriorly by a medium sized smoothed tooth, translucent but lacking a fenestra; the sternal carina divided posteriorly into a "V" which encloses a weakly concave area; petiole well separated from gaster in side view, its articulation with abdominal segment III relatively wide (HeW Holotype 0.17) but perfectly mobile; gaster elongated, its maximal width at the level of abdominal segment IV; abdominal tergite III with a short anterior vertical face; spiracle small but well sclerotized, circular and open laterally; abdominal sternite III with two thin converging carinae rising from the tergal crests of the helcium and enclosing a weakly concave ventral area which receives the posteroventral face of petiole when the gaster folds down; carinae laterally visible and forming small protuberances at their base, but not representing a crest; constriction present between pre- and postsegments of abdominal segment IV; spiracle diameters decreasing from segments III to V, the last one very small yet distinct without artificial distension of the gaster; spiracles VI and VII not visible; pygidium conspicuously rounded in lateral view; sting short, slightly curved at the apex.

Sculpture: cephalic sculpture typical of the genus. Capsule wholly sculptured with a combination of striae, rugosities and punctuations; frons and vertex medially impressed by a narrow longitudinal band of 4 to 6 long parallel striae, rising from the base of the frontal lobes and diverging just before the vertexal margin; the lateral margins of frons and vertex and the genae entirely covered by weakly sinuous aligned rugosities, the anterior two thirds of the head capsule seems uniformly striate; the rugosities appear coarser in the anterior one third because of their broader size and lack of punctuation and pilosity; frontal lobes rugo-striated; a small, smooth and shiny depression, not concealed by the scrobe, is obvious behind the external margin of toruli; ventral face of cephalic capsule with weak rugosities, diverging forward from both the sides of the genal carinae; almost all the dorsum of capsule is covered by scattered piliferous punctuations more or less aligned except on genae at the level of the antennal sockets, on the medial part of the frons and the vertex as well as on an area behind the hypostomal carina; punctuations denser dorsally than ventrally, conspicuously more impressed on the posterior two third of the capsule and especially dense at the transition between vertex and genae; clypeal dome smooth and shiny at its median third, dull and longitudinally striate laterally; mandibles smooth and shiny; pronotum and mesonotum with a dense piliferous punctuation except on a narrow median band and on anterolateral margins of the pronotum which are smooth and shiny; anterior margin of mesonotum lacking transverse striation; anepisternum smooth and katepisternum with sparse and weak longitudinal striae; metapleura conspicuously striated longitudinally; propodeum finely striated and punctuated laterally but medially smooth on its dorsal and posterior face, except several thin transverse apical striae on the dorsal rim of the propodeal foramen; petiole node dull with fine punctuations denser anteriorly and laterally; gaster and femora entirely covered by a sparse piliferous punctuation, weaker than on head and thorax; tibiae dull with denser punctuation.

Pilosity: abundant on head and body, including at least five types of setae of variable size and location: (1) long simple setae scattered on head as follows: 1 erect pair on each side of the clypeal dome, their length equal to the distance separating their bases, 1 erect pair conspicuously curved forward at the base of the mentum, 5-6 suberect and curved ventral setae, aligned on the external margin of mandibles, their length increasing towards the mandible apex; (2) setae slightly shorter than the previous ones, sparsely distributed on the body as follows: several setae bent apically on each side of the clypeal dome, 1 upward inclined pair on the anterior margin of the pronotum, 2-3 pairs on the lateral margins of the mesonotum, 5-6 aligned pairs on the lateral margins of the propodeum, 1 almost vertical and curved pair on each protuberance below the orifices of the metapleural glands, 3-4 pairs on the laterodorsal margins of the petiole node and several other very sparse erect setae on the tergites or inclined on the sternites of the gaster (including a row of setae at the posterior margin of the sternites and numerous very dense setae on pygidium and hypopygium; (3) appressed pubescence formed by dense setae, slightly shorter than the previous ones, rising from piliferous punctuation and distributed on most of the body as follows: several curved and very dense setae on the posterodorsal half of the head dorsum, several more or less curved setae sparser on the antennae but denser on their apical segment(sensillae), some appressed setae very sparsely distributed on the dorsal face of the mandible (including one seta inserted at the base of each tooth), many very dense setae on procoxae, 4-5 setae emerging at posterior margin of the ventral tooth of petiole; (4) setae conspicuously shorter than the previous ones, forming small fringe above the clypeal lamella; (5) erect setae, very thick and denticuliform, slightly shorter than the previous ones and distributed as follows: 10 setae on the anterior face of mesotibiae, one basal seta on the posterior face of the probasitarsus, inserted basally in the concavity in front of the strigile comb, several setae inserted at the apex of the four tarsomeres, as follows: prothoracic legs: 4, 2, 2, 0, meso- and metathoracic legs: 5, 4, 2, 0; in addition, a row of intermediate sized setae, from type (3) to type (4), are present on each side of vertex.

Color: body yellow-reddish, but cephalic capsule and antennae more reddish-brown; anterior and internal margins of toruli dark brown to reddish-brown visible through cuticle between frontal lobes; clypeal lamella margin with a fine reddish-brown border; mandibles yellowish to reddish, hardly clearer than cephalic capsule, its apical margin underlined by a wide dark brown-reddish border; teeth dark brownish to reddish, the apical tooth entirely black; outer margins of mandibles with a fine dark-brown border; ring of propodeal spiracle more reddish than remainder of propodeum; legs more yellowish than remainder of mesosoma; denticuliform setae of mesotibia conspicuously reddish.

Queen (plate 2).

Measurements (mm) and indices: means with standard deviations for the paratypes (n=10) given in (parenthesis); maximum range for the paratypes (n=10) given in {}: CivW (0.53±0,02) {0.51-0.56}; DPeW (0.31±0.02) {0.29-0.34}; HeW (0.22±0.02) {0.21-0.27}; HL (0.58±0.01) {0.57-0.60}; HW (0.55±0.01) {0.54-0.56}; ML (0.40±0.02) {0.38-0.42}; PW (0.54±0.02) {0.51-0.56}; PeL (0.32±0.02) {0.29-0.34}; SL (0.35±0.02) {0.33-0.38}; WL (0.94±0.02) {0.90-0.97}; CI (94.4±1.1) {93.4-96.7}; MI (68.3±3.51) {64.5-73.8}; SI1 (64.32±2.63) {59.3-67.8}; SI2 (60.69±2.53) {57.4- 63.5}; PrI (97.44±2.93) {93.22-101.72}.

Head: similar to worker but with well developed compound eyes and ocelli; average CI 94.4 (n=10 paratypes); CI range 93.4-96.7; head proportionally less broad in comparison with thorax, average PrI 97.44 (n=10 paratypes); PrI range 93.22-101.72; head sides not converging anteriorly; maximal width of head capsule at three-fourths distance from anterior clypeal margin to vertexal margin; ocelli well developed; eyes subcircular and globular, inserted slightly before the middle of head side, consisting of about 18 well defined ommatidia in its length and 13 in its width; antennae 10-segmented; scape very robust, conspicuously enlarged at three-fourths of its length; mandibles with stronger and acute apical and subapical teeth; maxillary and labial palps 1-segmented (2 dissected specimens).

Mesosoma: clearly broader than in worker, with typical pterosclerites of ectatommine queens, subrectangular in side view; dorsal faces of mesoscutum and scutellum weakly convex, separated by a quite visible suture; dorsal sclerite margin underlined by more or less developed bordering carinae; sides of mesothorax weakly convex and slightly converging posteriorly; posterior edge of mesoscutum with a clear median notch, prolonged anteriorly by a short superficial furrow, probably homologous, but in a very attenuated form, with the medial furrow that posteriorly prolongs the medially converging notauli in the male; parapsides parallel and weakly impressed, merely reaching the midlength of the sclerite; tegulae well developed; scutellum in the same plane as mesoscutum; mesoscutoscutellar suture rather broad; axillae well developed and laterally compressed, forming a large and deep depression near the bases of wing articulations; metanotum slightly compressed medially; suture between anepisternum and katepisternum well impressed and straight, reaching about the posterior three-fourths of the mesopleura length; mesospiracle barely visible with a very small elliptical orifice; propodeum short and rounded with a high subvertical posterior face; propodeal spiracle large, subcircular and opened posterolaterally; a weak depression is visible beyond. Wings normally developed; length of mesothoracic wing about 2.88 mm (n=1 paratype), its venation typical of the genus: cells R, 1R1, 1M and 1Cu closed; base of Rs and cu-a interrupted by a bulla; 2R1 opened, Rs not reaching the costal margin; 1Rs lacking; claval lobe depigmented and transparent; length of metathoracic wing about 2.15 mm (n=1 paratype); its venation very reduced: cell R long and closed, 1Cu opened (vein cu-a lacking), C lacking; 3 hamuli present at the level of a little sclerotized spot, not far beyond the middle of anterior wing margin; no jugal lobe.

Metasoma: similar but larger and longer than in worker; constriction between abdominal presclerite and postsclerite IV conspicuously impressed.

Sculpture: similar to but much more impressed than in worker. Frons and vertex with a narrow band of longitudinal striae larger than in worker and interrupted just before anterior ocellus; anterior border of mesoscutum with a short weak longitudinal depression smooth and shiny; katepisternum smooth and shiny; lateral sides of propodeum longitudinally striate, their upper half conspicuously punctuated.

Pilosity: as in worker but thicker; setae of type (2) a little denser on the scape; anterior margin of pronotum with 3 dorsal pairs of setae; eyes with short and very sparse setae; both faces of wing with numerous short setae, its costal margin with longer ones.

Color: darker than in worker; cephalic capsule more dark than the body, at least around ocelli and above the mandibles on the anterior third of the capsule; thoracic tergites margined by reddish carinae; a black spot visible under tegulae; wing membrane translucent, veins yellow to reddish; anterior wing weakly smokey and with a well developed reddishbrown pterostigma.

Male. (plates 3-4).

Measurements (mm) and indices: means with standard deviation for paratypes (n=10) given in (parenthesis); maximal range for paratypes (n=10) given in {}: CIvW (0.36±0,03) {0.33-0.39}; DPeW (0.23±0.02) {0.18-0.25}; HeW (0.17±0.02) {0.14- 0.19}; HL (0.46±0.02) {0.43-0.51}; HW (0.42±0.02) {0.39-0.45}; ML (0.28±0.02) {0.23-0.3}; PW (0.54±0.17) {0.5-0.59}; PeL (0.25±0.01) {0.22-0.27}; SL (0.26±0.01) {0.24-0.28}; WL (0.79±0.04) {0.73-0.85}; CI (89.8±4.1) {86-97.8}; MI (59.7±4.89) {51.1-68.1}; SI1 (62.2±1.96) {59.1-65.1}; SI2 (55.9±3.31) {52-61.7}; PrI (128.82±4.48) {120.45-136.36}.

Head: longer than wide, average CI 89.8 (n=10 paratypes); CI range 86-97.8; maximum width of capsule just beyond the eyes; vertexal margin slightly convex; posterolateral corners well rounded; head sides subconvex but not converging anteriorly; clypeal lamella very narrow, without median lobe; tentorial pits near base of toruli, in a depression which does not modify the posterior clypeal margin; eyes large and globular, slightly before the middle side of head; eye diameter equal to the half of capsule side; ocelli well developed; frontal lobes well developed, clearly inclined and partially covering antennal sockets; frontal lobes separated by a short frontal groove closed anteriorly by the clypeal dome and posteriorly by the convergence of the striae and rugosities of frons; frontal carinae diverging and softening posteriorly; toruli circular and clearly separated, their internal rim raised and merging with base of frontal lobe; antennae 12-segmented; scape almost straight, weakly bent ventrally at its midlength and without longitudinal carina; scape about as long as the 3 following segments together, when folded backward, its apex does not reach the vertexal margin; funicular segments conspicuously longer than wide and weakly thicker from the base to apex; pedicel more than two times longer than wide and about 1.5 times longer than the following segment; funicle not clubbed; apical segment conspicuously longer than the others, and more than twice as long as the penultimate; mandibles quite well developed, average MI 59.7 (n=10 paratypes); MI range 51.1-68.1; mandible shape similar to that of worker, with a long apical tooth, falciform and acute, narrower than in females, and a strong and short subapical tooth sometimes preceded by a tiny blunted tooth; palps 1, 1 (2 specimens dissected).

Mesosoma: broader than in worker, its dorsal face more convex than in queen; sutures between dorsal sclerites clearly visible; sides of mesothorax less converging posteriorly than in queen; mesonotum with notauli well marked anteriorly and converging backward in a fine furrow reaching the posterior margin of the mesoscutum; mesoscuto-scutellar suture wide; parapsides feebly marked but distinct, almost parallel; axillae well developed and compressed laterally; metanotum weakly compressed medially with a small protuberance differentiated beyond the scutellum; suture between anepisternum and katepisternum straight and distinct across entire mesopleura; mesospiracle barely visible, its orifice very small and elliptic; propodeum with a flat and sloping dorsal face and a vertical posterior face; propodeal spiracle wide and elliptic, opening posteriorly. Legs conspicuously longer and thinner than in females; profemora and metafemora laterally compressed and curved at their basal third; tibial spurs 1, 1, 1; metatibial spurs simple and slightly pectinate; strigile curved and widened at its base; probasitarsus curved and almost as long as the protibia; mesobasitarsus as long as mesotibia and about two thirds as long as metabasitarsus; tarsal claws acute, with a small subapical tooth. Wings as the queen; anterior wing length about 2.85 mm (n=1 paratype).

Metasoma: Petiole short and sessile, with a broad dorsal constriction between presegment and postsegment; petiole node less expanded than in females, but similarly shaped, forming a weak subtriangular scale in side view; anterior face of node flat and greatly inclined, lateral faces convex but not convergent and dorsal face hardly differentiated, short and gradually rounded posteriorly; node subrectangular to trapezoidal in dorsal view, with very rounded angles and about 1.5 times wider than long; anterodorsal margin rounded; posterodorsal margin straight; spiracles open slightly latero-ventrally on the basal protuberances of the node; tergosternal suture as in worker; petiole with a ventral process bearing a median carina but without differentiated tooth; ventral process divided posteriorly into a "V" which encloses a flat area; petiole less differentiated from gaster in side view than in females, its articulation with abdominal segment III perfectly mobile but relatively broad, average HeW 0.17 (n=10 paratypes); HeW range 0.14-0.19; abdominal tergite III without obvious anterior face; spiracle small and circular, opening laterally; sternite III with two converging carinae rising from tergal crests of helcium and enclosing ventrally a V-shaped flat surface; carinae barely visible laterally, not protruding at their base; a strong constriction fully visible dorsally between abdominal pre- and postsegment IV, the presegment partially concealed by abdominal postsegment III; spiracle of abdominal segment IV as in segment III; spiracle of abdominal segment V small but visible without artificial distension of the gaster; spiracles of abdominal segments VI and VII not visible.

Genitalia well developed and sclerotized (2 specimens dissected). Genital capsule length about 0.45 mm, partially retractile, slightly projecting beyond abdominal segment VII in lateral view; color yellow-reddish; abdominal sternite VIII small, larger than long, apex truncated and not notched medially; pygostyles (abdominal tergite X) connected to abdominal tergite IX by a weakly sclerotized membrane; subgenital plate (abdominal sternite IX) feebly sclerotized and yellowish, triangular shaped and about as long as wide, ending in a reddish slightly up-curved digitiform process which bears seven aligned medium-sized setae laterally and five or six longer setae ventrally; subgenital plate triangular shaped, with its anterior margin well sclerotized, bearing a long median process, very thick, sharply truncated and slightly up-curved; basal ring broad, feebly sclerotized, connected laterally with basiparameres and ventrally with parameres; parameres joined only dorsally at their base, the valves completely open ventrally enclosing volsellae and aedeagus; suture line between basiparamere and paramere distinct; parameres triangular shaped in lateral view, their apex conspicuously rounded and covered externally with numerous simple setae; volsellae well developed and sclerotized, with a large lamina bearing ventrally about 17 small simple setae; apicoventral part not produced as a lobe; a large ventral process protruding laterally from the base of the laminae volsellaris (alv), its length shorter than two times its width; digitus massive, ending up ventrally in an acute or right angle, its dorsal corner weakly pointed; outer surface of tapered digitus apex with scattered and very short setulae; cuspis absent; aedeagal plate well sclerotized, its ventral margin almost straight basally and its distal half forming apically a rounded apical lobe; serrate margin with about 24 aligned barbs, all short, large, acute, anteriorly projecting and vertically oriented; teeth larger on the 2/3 distal part of the ventral margin; distal margin of aedeagal plate without apical corner, nor concavity; aedeagal apodeme well developed, long and wide; aedeagal plate with dorsal part of the anterior margin not excavated above the base of aedeagal apodeme.

Sculpture: Cephalic sculpturation coarser on head but weaker on thorax than in worker; dorsum of head entirely sculptured, with a combination of striae, rugosities and piliferous punctuations; frons and vertex with a longitudinal band of about 16 striae interrupted at the level of ocelli; striae laterally substituted by rugosities covering the lateral edges of frons and vertex, and partially the sides of the capsule; genae with sparse punctuations behind the eyes; ventral face rugo-punctuate; clypeus dull and rough, its median part smoother; pronotum smooth and shiny, with very sparse punctuations, except its posterior margin bearing a dense piliferous punctuation; mesoscutum dull with a dense piliferous punctuation, except a more shiny and less punctuated median band; a short median longitudinal furrow at its anterior margin; mesopleura smooth and shiny; scutellum apparently smooth, but very finely striated longitudinally; base of metapleura longitudinally striate, its upper part smooth and shiny; metapleura separated from propodeum by a groove; petiole smooth, except some discrete longitudinal rugosities on the sides of the sternal process; gaster smooth and shiny, with a sparse piliferous punctuation, more superficial than on head and thorax.

Pilosity: Head and body conspicuously hairy, but pilosity reduced on the sides of mesosoma; eyes more or less glabrous; setae as in worker, but without those of type (5); pilosity distributed as follows: setae of type (1) as in worker; setae of type (2): one pair on pronotum, two pairs on mesoscutum, three pairs on scutellum, two pairs on metanotum, one pair on each protuberance below the orifices of metapleural glands, two pairs on the laterodorsal margins of petiole, and others very sparse on gastral segments (including a range of setae aligned on the posterior margin of the sternites and numerous very dense setae on pygidium and hypopygium; setae of type (3): dense on head dorsum and genae, but lacking anteriorly; a range of aligned setae on the posterior margin of pronotum; many dense setae on sides of mesoscutum; several setae on the lateral edge of scutellum and very sparse others on propodeum; dense setae on petiolar node and gastral segments; femora and tibiae conspicuously pubescent; setae of type (4) as in worker.

Color: Body reddish to brownish; cephalic capsule completely brownish, almost black; clypeus and frons reddish; mandibles and antennae yellowish; eyes grayish; external margin of mandible with a broad reddish edging; apical tooth reddish; mesosoma and metasoma reddish, mesonotum a little darker; mesoscutum with a central band slightly clearer than lateral margins; notauli grooves black; sutures between dorsal thoracic sclerites underlined by narrowed brownish carinae; legs yellowish and dull; wings weakly smokey with yellowish veins.

Taxonomic position and discussion

This new species keys to Typhlomyrmex in Bolton (1994), and it has most of the characters in Brown's (1965) genus diagnosis. The only differences found between T. meire and the genus diagnosis are the number of antennal segments in both sexes and the antennal club shape in the females. According to Brown (1965), the females of Typhlomyrmex have 12- segmented antennae with the three or four last ones forming a club, while the males have 13-segmented antennae. In T. meire , female antennae are only 10-segmented with the two last segments forming a club. In the male, the antennae are 12-segmented. Although this species does not fit perfectly into the Typhlomyrmex diagnosis sensu Brown (1965), it cannot be assigned to another known ant genus and it is therefore necessary to modify the diagnosis given by Brown (1965). A reduced number of antennal segments is rather common in the poneromorph subfamilies sensu Bolton (2003), as, for example, females of Amblyopone degenerata Borgmeier with four to seven antennal segments (see Lattke, 1991) and Prionopelta punctulata Mayr with 11 segments (see Brown, 1960).

Distribution and ecology

Typhlomyrmex meire n. sp. was collected for the first time in 1986 in an experimental parcel on the grounds of the Cocoa Research Center (CEPEC) at Ilheus, Bahia State, Brazil. This area, where the cocoa trees were cultivated according to the "cabruca" mode, showed a very diversified myrmecofauna (see for example, Delabie & Fowler, 1995; Delabie et al., 2000) before its complete deforestation in 1997. It was in this parcel that Simopelta minima (Brandao) , exclusively known from its type-series and today possibly extinct, was collected. After 1986, several other specimens of T. meire were occasionally found in the same region, in cocoa plantations or forest remnants. All collections were concentrated in the Ilheus surroundings, which are in the Atlantic Forest biome. Typhlomyrmex meire seems thus endemic to Southern Bahia and is found sympatrically with two other species of the genus: T. rogenhoferi and T. pusillus . In contrast to the two strictly terricolous species, T. rogenhoferi nests only in dead tree logs (Lacau et al., 2001 and 2003; Lattke, 2003) and does not seem to compete with them. Typhlomyrmex clavicornis , which shows the strongest phylogenetic affinities with T. meire , does not occur in the region, while it is present in the Rio de Janeiro State (Lacau et al., unpublished data).

The type-series of T. meire is composed of a fragment of a colony found in June, 2002 in a nest (Plate 5) of the termite Syntermes grandis Rambur , 1842 (Termitidae: Nasutitermitinae ). This termite nest was found in an irregular parcel of cocoa plantation and measured1.20 meter high. The ant colony was at the middle-height of the nest, about 15 cm deep. The ant nest was composed of numerous small galleries, each a few centimeters long. The annual average temperature of the locality is 23.3°C, and the annual average rainfall is 1,687 mm (data from the Climatology Section of CEPLAC/CEPEC). Typhlomyrmex meire workers have never been collected on the ground or in the litter, even during the numerous studies performed in the region during the last 15 years by the Myrmecology laboratory of CEPEC. This clearly indicates that the species is strictly hypogaeic.

The field study of several T. meire societies showed that their nests are always situated a few centimeters from a colony of Acropyga fuhrmanni (Forel) (Formicidae: Formicinae ). Acropyga are strongly dominant in the regional cocoa plantation soils (Delabie et al., 1991). Behavioral laboratory observations showed that T. meire is in fact a specialized predator on imagos and immature stages of A. fuhrmanni (Lacau et al., 2003, cited as A. berwicki Wheeler , but recently synonymized under A. fuhrmanni by LaPolla, 2004).

Key to Typhlomyrmex workers (modified from Brown, 1965)

1. Clypeal dome with anterior face vertical or subvertical (head in side view); mandible shape elongated-subtriangular, their basal margins weakly convex, not reaching the anterior clypeal margin at full closure; anterior face of mesotibia with about 10 denticuliform erect setae......................................................................... 2

- Clypeal dome with anterior face sharply inclined posteriorly (head in side view); mandible shape triangular, their basal margins rectilinear or weakly concave, fitting tightly against clypeus at full closure; anterior face of mesotibia without denticuliform setae...................................................................................................... 3

2. Antennae 12-segmented; clypeal margin straight and totally concealed by the clypeal dome in dorsal view ....................................................... T. clavicornis Emery

- Antennae 10-segmented; clypeal margin weakly convex medially and only partially concealed by the clypeal dome in dorsal view........................ T. meire n. sp.

3. Petiole well pedunculate in lateral view; node poorly developed, longer than high, subconvex at its top and without a distinct posterior face; abdominal tergite III without obvious anterior face; size polymorphism marked...... T. rogenhoferi Mayr

- Petiole weakly pedunculate in lateral view; node well developed, higher than long, well rounded at its top and with a distinct posterior face; abdominal tergite III with a distinct anterior face; monomorphic................................................................... 4

4. Metafemora base (posterior view) sharply swollen ventrally, so that it forms a short vertical face at the base, joining the ventral face by an obtuse and rounded angle; head width>0.55 mm........................................................ T. major Santschi

- Metafemora base (posterior view) poorly swollen ventrally, so that it does not form an angle at its base; head width <0.55 mm.......................... T. pusillus Emery