Blepharidatta brasiliensis Wheeler

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) : 42-45

Blepharidatta brasiliensis Wheeler

( Figs 1 A – B, 2 A – B, 3 A – B, 4 A – B, 6 A – I, 9)

Blepharidatta brasiliensis Wheeler, 1915: 484 , workers. Fig. 1. Brazil.

References: Lattke, 1985: 51 (workers, Venezuela, Alto Mavaca). Diniz (1994) (biology). Wheeler & Wheeler, 1991: 134–5 (larva). Rabeling et al., 2006 (biology). Franken et al., 2013 (relative frequency).

Lectotype worker (here designated) and 9 paralectotypes: BRAZIL: Pará: Belém , Beebe col., May, 1915 [ MZSP] (examined) ; 9 “ cotype ” workers (syntypes), same locality, [ MCZ no. 9040] (not examined) .

Lectotype measurements: HL 0.65; HW 0.45; SL 0.45; ML 0.15; WL 0.7; PL 0.4; Ppl 0.15; Hfl 0.65; GL 0.6.

Diagnosis (worker). Relatively small ants (total length of workers circa 2.5 mm). Body predominantly yellowish, opaque, densely areolate, and discretely rugulose. Eye rounded and strongly protruding. Propodeal spine shorter than petiole in lateral view. Petiolar node dorsally rounded in lateral view.

Worker measurements (n=7): HL 0.6–0.75; HW 0.4–0.5; SL 0.45–0.5; ML 0.15–0.25; WL 0.65–0.75; PL 0.35–0.45; Ppl 0.15–0.2; Hfl 0.6–0.75; GL 0.55–0.75.

Worker description ( Figs 1 A – B). Color uniformly yellowish, with slightly darker gaster and almost transparent frontal carina; appendages yellowish. Body densely covered by minute areolate rugulose sculpture units, superposed by regularly spaced longitudinal rugulae on head; gaster mostly smooth. Mandible with short longitudinal irregular striae covering two thirds of mandibular blade basally; central portion of clypeus with relatively pronounced longitudinal and transversal carinae forming rough reticulation over fine and uniform reticulation. Scrobe divided into four distinct parts, the anterior one is deeper than the rest of the scrobe and accommodates base of antenna; the second area shows 3–4 transverse curved striae over areolate rugae, followed by a deep, almost smooth area, and a posterior area of transversally oriented sculpture units, ending with areolate rugulae. Dorsal surface of head with five prominent longitudinal rugulae at each side. Compound eye set within a net of polygonal cells formed by rugulae, better seen in lateral view, three long and parallel cells anterior to eye, and seven irregular foveae posterior to eye, the first double and others in a row. Mesosoma sculptured throughout entire surface, with irregular, vermiculate, longitudinal rugae over areolate sculpture. Petiole and postpetiole with two longitudinal rugae in lateral view. Areolate sculpture concentrated on the anterior one fifth of gaster, otherwise smooth and shining. Appendages regularly areolate.

In general, body covered by sparse hairs; hairs stiff, long, slightly curved, uniform in width, and truncate; some of them in pairs. Dorsum of mandible with subdecumbent to appressed flexuous short hairs; frontal carina with 6– 7 regularly spaced and upwards bent hairs. Dorsum of petiolar node and postpetiole with sparse hairs, mostly in pairs; ventral face of petiole devoid of hairs; ventral face of postpetiole with a single pair of hairs. Anterior face of coxa with a long and erect hair. Legs otherwise covered by appressed small pilosity.

Cephalic occipital corner tuberculate in frontal view. Scape and funiculus partially lodged in scrobe, which is not wide enough to receive whole scape; frontal carina does not cover scrobe, internal area of scrobe visible even with the head in frontal view; convex compound eye with about eight to nine facets along maximum diameter. Ventral face of head slightly convex, head wider anteriorly than rest in lateral view.

Promesonotum slightly convex medially in anterior view, followed by attenuated curve to lateral margin; straight in profile, anterior margin angular; dorsum of promesonotum higher than propodeal dorsum; pronotal humeral angle pointed, slightly bent forwards; anteroventral corner pointed; metanotal groove shallow but clearly visible in lateral view; mesometapleural suture absent or faintly marked, not clearly separating the meso- and metapleuron on the sides of mesosoma; bulla of metapleural gland indistinct; dorsal profile of propodeum straight; propodeal spines relatively long and slightly directed posterodorsally; infraspinal lamella present and fused to propodeal lobe; propodeal lobe subquadrate in side view, length close to one-third of propodeal spine length.

Petiole pedunculate, node moderately elevated and dorsally rounded, posterior face weakly sloped in lateral view; postpetiole feebly convex dorsally and without ventral processes. Gaster suboval, tergum I anterolaterally angular in dorsal view.

Sting apparatus ( Figs. 6 A – I). Spiracular plate sub-rectangular, body extends towards median connection; spiracular external margin separated from ventral plate margin by distance equal to the internal diameter of spiracle; ventral tubercle absent. Quadrate plate apodeme of same size as plate body, anterodorsal corner with distinct projection and rounded apex. Anal plate as in other Blepharidatta species. Oblong plate with short posterior apodeme; subterminal tubercle absent. Gonostylus membranaceous with short terminal band. Triangular plate dorsal tubercle prominent and indistinct; median tubercle absent. Lancets as in other Blepharidatta species. Sting base with distinct antero-lateral processes, slender; campaniform sensillae of valve chamber present beyond basal half of sting shaft; sting reduction index 37. Furcula dorsal arm length smaller than side arm’s length.

Gyne measurements (n=1): HL 0.70, HW 0.50, SL 0.5, ML 0.15, WL 0.70, PL 0.45, Ppl 0.15, HfL 0.65, GL 0,85.

Gyne (ergatoid) description ( Figs 2 A – B). Similar to conspecific worker, differing by the slightly larger body size and more robust gaster.

Male measurements (n=1): HL 0.45; HW 0.35; SL 0.15; ML 0.2; WL 0.7; PL 0.3; Ppl 0.1; Hfl 0.45; GL 0.6.

Male description (Figs 3 A – B). Body yellowish-brown, with head, scutum, and first third of gaster slightly darker; appendages yellowish. Body areolate, especially on head; sculpture on lateral portions of mesosoma almost indistinct. Gaster smooth and shiny. Long, subdecumbent, cream-colored hairs sparsely covering head and mesosomal dorsum, denser on 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 as long as 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, humeral angles discrete and rounded; scutum large, rounded anteriorly and with slightly convex posterior margin; notauli distinct. Prescutellum narrow; scutellum wider than long. Metanotal suture well-marked and shallow. Propodeum unarmed, slightly angular in profile, dorsal profile short, declivity almost vertical.

Wings dark amber and covered by dense pubescence (Fig. 3 A – B); venation reduced; pterostigma vestigial; longitudinal veins Sc+R, Rs, M, Cu, and A present; Rs, M, Cu not extending to the external margins of wing; cells C, R and SR closed. Hind wing with R+Rs and M+Cu veins only.

Petiole pedunculate, with a subrectangular dorsal node; ventral processes absent. Postpetiole subquadrate in dorsal view, slightly broader than long, and attached to gaster by almost its full width. Gaster elongate, tergite I anterolaterally feebly angular.

Larva (modified from Wheeler & Wheeler, 1991, which based the description on 12 larvae from Alto Mavaca, Amazonas, Venezuela). With the characters of Blepharidatta larvae but with few head hairs, all very short except for the two near midline. Hypopharynx with minute spinulae in arcuate rows.

Comments. Blepharidatta brasiliensis is a central to western Amazonian species recorded in Brazil (states of Acre, Amazonas Pará and Rondônia), Colombia (Vaupés), Ecuador (Napo) and Venezuela (Amazonas). Lattke (1985) recorded B. brasiliensis in Venezuela, Territorio Amazonas, San Carlos de Río Negro, collected by L. Garvin in December, 1981, probably deposited in MIZA.

The record of B. brasiliensis workers by Gallardo (1916) in Argentina, Córdoba province, Altagracia, deposited in the Museo Argentino de Ciencias Naturales Bernardino Rivadavia actually proved to represent Wasmannia auropunctata , according to the curator, Dr. Arturo Andrés Roig.

Diniz (1994) studied B. brasiliensis biology in a Manaus city development (Conjunto Acariquara), at the University of Amazonas campus and also at the Reserva Ducke. He observed the ants using rolled fallen leaves and natural cavities in rotten logs as nesting sites; in half out of the eight examined nests, he found insect carcasses around the nest openings. Worker populations of the eight colonies Diniz collected ranged from 49 to 117. One colony had only a single ergatoid gyne, while the others had 3–14 ergatoids; males ranged from 0 (four colonies) to 12. Diniz (op. cit.) listed the items found in pieces or sometimes in whole bodies around collected nests of B. brasiliensis : spiders, diplopods, orthopteroids, beetles, flies, unidentified Hymenoptera and ants of the genera Camponotus , Cephalotes , Crematogaster , Dolichoderus , Ectatomma , Nesomyrmex , Pachycondyla , Pheidole , Pseudomyrmex , and Solenopsis . Diniz observed at least once the migration of a colony from one rolled leaf to another, with workers also transferring the carcasses found within and around the nest opening. He also observed that workers keep the larvae in between the mandibles while inside the nest. In two nests, Diniz (op. cit.) recorded isopod inquilines that suffered no hostility from the workers.

Rabeling et al. (2006) described the non-homogeneous nest distribution of B. brasiliensis in a locality near Manaus, AM, Brazil (EMBRAPA campus). The colonies occupied either cavities within rotting branches (more commonly) or natural spaces between leaves (19% out of 26 studied nests), apparently taking advantage of preexisting cavities, reducing the cavity size, if too large, or sealing it by means of a chamber wall, built from a mixture of soil, vegetable debris, and insect parts. According to them, “ B. brasiliensis appears to take advantage of pre-existing cavities, which were only slightly modified by them. The shape of the main chambers was amorphous ellipsoid to round and had an inner dimension of 4 cm length by 1.5 cm width. If pre-existing cavities in branches were too large or the nest was located between leaves, the ants had reduced the nest volume by constructing chamber walls, built from a mixture of soil, vegetable debris, and insect parts in order to seal off the nest chamber.” As in Diniz (op. cit.), they also observed that colonies were polygynous with one to eleven ergatoid gynes and with 132 workers on average ( SD = 95.63). Nests contained large numbers of brood (roughly 75% larvae and 25% pupae), which were kept lying on the bottom of the nest chamber. If a colony was disturbed, workers picked up the immatures and held them between their mandibles. The colonies they studied appeared to be mostly active at night and to be omnivorous, scavenging or preying on beetles, bees, cicadas, crickets, termites, spiders, and ants of the genera Cephalotes , Pheidole , Camponotus , and Pachycondyla . The victim’s legs and antennae were cut off before being dragged to the nest. Blepharidatta brasiliensis may also collect nutrient-rich plant structures, such as seeds or elaiosomes, in addition to the arthropod diet.

Franken et al. (2013) recorded B. brasiliensis in the litter trapped around Attalea attaleoides (Barb. Rodr.) Wess. Boer palm bases, which is a refuge for non-dominant ant species because aggressive species in these microhabitats are relatively rare. The trapped litter was occupied mostly by unaggressive predatory and fungusgrowing species, which probably find more prey or better conditions to cultivate their food there.

Blepharidatta brasiliensis may be rather frequent in some Amazonian areas; for instance, Oliveira et al. (2009) recorded B. brasiliensis in 8.7% of the 850 pitfall traps and sardine baits set in 30 plots and from litter sifting (Winkler sacks) in 25 plots at Reserva Ducke in Manaus (the 5th most frequent ant species out of the 152 recorded in the area).

Material examined: BRAZIL: Acre: Cruzeiro do Sul , 23– 28.xi.1983, F. H. Caetano (“ folhiço # 4 ), 1 worker ( MZSP) . Amazonas: Manaus, viii.1962, K. Lenko # 4130 , 69 workers, 7 gynes [4 workers CPDC, 4 workers, DZUP, 4 workers EUEC, 4 workers HCJG, 4 workers ICNC, 4 workers INPA, 4 workers MCZ, 7 gynes, 37 workers MZSP, 4 workers USNM] ; Manaus, Km 24 ZF3 , 21.iii.1983, WWF, camp Floresta, E.O. Wilson [ MZSP], 1 worker; Manaus, INPA, 02.x.1987, J.L.M. Diniz, 4 workers, 1 gyne [ MZSP] ; Manaus, Ig. Marianil, Rio Branco , Rod 24, NE Manaus , ix.1962, W.L. Brown Jr. ( Kempf collection #4565 ) 18 workers [ MZSP] ; Dimona, approx. 80Km N of Manaus , viii.2000, U. Mueller & R. Adams 8 workers, 1 male [ MZSP] ; Manaus to Itacoatiara Km 50 (M-61), W.L. Brown Jr. 24.viii.1962, 3 workers [ MZSP] ; Manaus, Conjunto Acariquara , 24.xi – 7.xii.1987, 10 workers, 1 male, 1 gyne, J.L.M. Diniz (Diniz collection #2340 ; 2327 ) [4 workers HCJC, 6 workers MZSP] . Pará: Belém , 15.v.1915, C.W. Beebe (lectotype) 1 worker [ MZSP] ; Jari, Corte Seletivo , 0º53'S, 52º36'W, 2011, E.A. Silva, 58 workers [24 DZUP, 4 HCJG, 4 EUEC, 26 MZSP] ; Utinga tract, nr. Belém , 12.viii.1962, W.L. Brown 1 worker, 1 male [ MZSP] ; Porto Trombetas , viii.1992, J.D. Majer ( #12 ), 11 workers [ MZSP] . Rondônia: Porto Velho, Área Caiçara , 09º26’13.0”S 64º48’04.1”W, 19.vi – 02.vii.2010, R.M. Feitosa & R.R. Silva, 35 workers [20 DZUP, 15 MZSP] . COLOMBIA: Vaupés, Tararaira, Est. Biol. Caparu , 0 1o04’S, 69o31’W, altitude 85 m, 14– 20.v.2001, A. Sabogal [ UNAB], 13 workers [7 ICNC, 6 MZSP0 . ECUADOR: Napo, Cuyabeno , 12.x – 5.xi.1994, J. P. Caldwell ( #10342 ), 1 worker [ CPDC] . VENEZUELA: Amazonas, Alto Mavaca , 05.xi.1989, J. E. Lattke ( #1255 ), 10 workers [3 DZUP; 7 MZSP] .