Myrmicocrypta camargoi

Sosa-Calvo & Schultz (2010) - Workers of this species have been collected in Cerrado habitat in Botucatu (Sao Paulo) and Jatai (Goias) and in Mata Atlantica (Atlantic forest) in Floresta da Tijuca (Rio de Janeiro) and Santa Teresa (Espiritu Santo). The nest series from Botucatu was collected while digging out a colony of Atta capiguara Goncalves in a pasture field composed mostly of Brachiaria spp. and Paspalum spp. (Poaceae: Panicoideae). Workers were observed carrying small pieces of dry grass, but the nest entrance was not located (R. S. Camargo, personal communication).

Identification
Sosa-Calvo & Schultz (2010) - (Worker). The largest known species of Myrmicocrypta (TL > 4 mm); body covered with erect hairs; frontal lobes, in full-face view, evenly rounded and, in profile, strongly protruding; antennal scapes covered with simple, suberect hairs; lateral pronotal and lateral mesonotal spines long, the latter longer than the former and blunt at apex.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 *  camargoi. Myrmicocrypta camargoi Sosa-Calvo & Schultz, 2010: 184, figs. 1-15 (w.q.m.) BRAZIL.

Worker
TL = 4.58 (4.49-4.89); WL=1.36 (1.33-1.46); HL= 0.97 (0.94-1.02); HW = 0.74 (0.72-0.80); SL = 1.13 (1.10-1.19); ML = 0.61 (0.58-0.69); EL = 0.12 (0.11-0.12); PL = 0.39 (0.39-0.42); PPL = 0.22 (0.21-0.23); GL = 1.03 (0.97-1.13); CI = 76 (76-81); SI = 153 (147-154); MI = 63 (60-71); FLD = 0.31 (0.28-0.34) (n = 10).

Head. Almost 1.3X as long as wide (excluding mandibles); in full-face view head narrowing posterior to eyes, posterior corners more or less evenly rounded; head dorsally with erect, spatulate hairs on carinae, areas between carinae lacking pilosity; sculpture on head restricted to discrete carinae, areas in between smooth, minutely punctate; in full-face view, frontal carinae branching posteriorly into fully developed median vertexal carinae and continuing laterally to connect with a carina arising in area of eye, possibly preocular carina; denticles occur at junctions of carinae forming, in lateral view, projections of almost similar size and shape; eyes with seven to eight ommatidia in longest row and 37-42 in total; eyes globose, located posterior to middle of head at level above frontal lobes; antennal scapes very long and thin, slightly thickened at apex; antennae with 11 segments; antennal flagellum gradually thickened distally rather than abruptly clubbed, last three segments noticeably larger than rest, last two very much so, all typical for Attini; antennal scapes surpassing occipital corners by > 0.4X scape length; anterior border of clypeus hyaline, shining, and imbricate, with a distinct median angle; clypeal setae arising from posterior margin of clypeal apron and consisting of six to seven pairs of simple, appressed hairs slightly overhanging mandibles and single thick, long (0.16-0.19 mm) unpaired median seta that originates from posterior of clypeal apron, slightly anterior to junction of clypeal apron and body of clypeus (sensu Kugler 1994:22 defined as: “the medial portion of the clypeus anterior to the frontal lobes and dorsal to the clypeal apron”); frontoclypeal teeth acute, covered with suberect simple hairs; mandibles with eight to 10 teeth, increasing uniformly in size from base to apex; sculpture on dorsal surface of mandibles rugulose-strigulate, frontal lobes evenly rounded, expanded laterally (0.28-0.34 mm), covering antennal insertions; in profile, frontal lobes strongly protruding; posterior margin of hypostoma with simple hairs that project over hypostomal plate. Dorsum of hypostomal plate shining and glabrous; anterior-lateral margin of hypostoma with a pair of acute teeth; in profile, occiput drawn out posterolaterally into an enlarged bilobed “neck” or “collar” that extends backwards, covering anterior-lateral portions of pronotum. Mesosoma: median pronotal tubercles present, small; humeral tubercles present, = 1.5 X length of median pronotals; lateral pronotal tubercles long and robust, = 2 X length of median pronotals, directed forward; lateral mesonotal tubercles longest on mesosoma, = 2X length of lateral pronotals; first median anterior mesonotal tubercles absent; second median posterior mesonotal tubercles present, acute, subequal in length to humeral tubercles; first and second posterior mesonotal tubercles present, small, subequal, joined by carinae, similar in size to median pronotals; inferior angle of pronotum evenly rounded; propleuron, adjacent to inferior pronotal edge, lacking distinct tubercles, site bearing roughenings and erect, spatulate hairs. mesonotal groove shallow but conspicuous. Metanotal groove deep and conspicuous, with median longitudinal carina. Base of propodeum, in profile, flat and slightly longer than declivity; both laterally carinate; propodeal spines reduced to tubercles. Base of forecoxa with a conspicuous and lamellate carina. Metasoma: petiolar peduncle lacking ventral process; node of petiole, in dorsal view, rounded anteriorly and longer than wide and, in lateral view, anteriorly rounded and posteriorly straight; postpetiole, in dorsal view, 1.3X wider than long; posterior border emarginate; posterolateral postpetiolar processes absent; dorsum of abdominal segment IV (gaster) finely reticulate and covered with short, erect, spatulate hairs; very subtle longitudinal sculpturing visible anteriorly; anterior margin straight, anterior lateral carinae absent. Individuals yellow to light ferruginous; pilosity restricted mainly to tubercles and carinae, spoon-shaped or spatulate; antennal scapes and legs with simple, erect hairs.

Queen
TL = 7.42-7.51; WL = 2.13-2.18; HL = 1.20-1.24; HW = 1.05-1.13; SL = 1.44; ML = 0.42; EL = 0.22-0.25; PL = 0.67-0.72; PPL = 0.38-0.39; GL = 2.15-2.22; CI = 85-94; SI = 127-137; MI = 67-69; FLD = 0.42-0.43 (n = 2).

Similar to worker except for differences typical of caste. Head: In full-face view, excluding mandibles, slightly longer than wide with lateral and posterior margins straight, posterior corners more angular and less rounded than in worker; vertexal carinae conspicuous and lamellate, each produced into a series of three processes: a pair of obtuse, triangular denticles flanking anterior ocellus, a pair of rectangular lamellae overhanging posterior ocelli, and a pair of long, acute, spinelike denticles mounted on vertex; cephalic margin with raised carina; posterior ocelli very small, median ocellus small (0.06 mm in diameter); frontal carinae complete to junction with vertexal carinae, but lateral branches absent (present in worker); supraocular tubercle present; mandibles with 11 teeth; clypeus as in worker and likewise with 7-9 pairs of hairs and with a long unpaired median seta (length = 0.22-0.23 mm). Mesosoma: Median and lateral pronotal and humeral tubercles present, well developed; inferior margin of pronotum evenly rounded; in lateral view, propleuron adjacent to inferior pronotal edge weakly and obtusely angulate; median pronotal spines connected by a weak carina, easily visible in frontodorsal view; mesoscutum with notauli (i.e., median pair of longitudinal carinae) carinate and extending through entire length of mesoscutum, developed anteriorly into blunt triangular denticles; median sulcus present as a low raised carina on anterior half of mesoscutum; parapsidal lines present as carinae in posterior half of mesoscutum; transscutal articulation present; parascutal lobes prominent and well developed, in lateral view posteriorly narrowed to a blunt, acute angle, tip bearing a transverse lamella on its outer face visible in oblique or dorsal view; axillae large, in dorsal view tapering posteriorly, dorsal and lateral margins developed into lamellae that form excavated, hemispherical concavities visible in posterior view; scutellum without lateral projections and ending posteriorly as two prominent dorsoventrally extended, laterally compressed, distally rounded processes; base and declivity of propodeum laterally carinate, carinae continuing downward to join propodeal lobes; propodeal teeth short, triangular; pleural suture wide and deep. Metasoma: Peduncle of petiole with a pair of dorsolateral longitudinal carinae along nearly entire length; petiole with a pair of ventral carinae that may (one individual) or may not (one individual) end anteriorly in a small tooth-like process, visible laterally; node of petiole dorsolaterally carinate; postpetiole in dorsal view 1.9 X wider than long, with pronounced posterolateral corners, posteriorly emarginate; tergite of abdominal segment IV finely reticulate-punctate. Wings: Forewing (length 4.80 mm) with very reduced fenestra, which appears as a rounded spot near apical margin; hind wing (length 3.57mm) with one closed cell. Head and body dark ferrugineous; gaster yellowish to light ferrugineous; wings smoky. Pilosity as in worker.

Male
TL = 5.96-6.34; WL = 1.90-1.98; HL = 0.90-0.94; HW = 0.77-0.83 (including eyes = 1.08); SL = 0.48-0.54; ML = 0.48-0.58; EL = 0.37-0.40; PL = 0.64-0.73; PPL = 0.23-0.33; GL = 1.64-1.86; CI = 82-92; SI = 58-70; MI = 53-62; FLD = 0.25-0.29 (n = 4).

Head. In full-face view, triangular, wider posteriorly and laterally angulate, cephalic margin interrupted laterally by a pair of tubercles and medially (behind posterior ocelli) by a pair of denticulate tubercles mounted on posterior extensions of vertexal carinae; ocelli larger than those in gynes, median ocellus 0.12 mm in diameter and with its anterior margin slightly concave or straight, posterior margin evenly rounded; frontal carinae extending posterad to intersect with vertexal carinae, not continuing laterad; low tubercles present at point of intersection; a median carina extends from between frontal lobes to anterior margin of median ocellus, more pronounced anteriorly, weaker posteriorly; dorsum of mandibles punctate; masticatory margin with eight to nine teeth gradually diminishing in size toward base; outer margin of mandibles slightly convex; frontoclypeal teeth present, short, blunt; anterior margin of clypeus hyaline, shining, and imbricate; three to four pairs of lateral clypeal hairs barely exceeding the anterior clypeal margin, a single thick median seta ~ 0.07 mm in length; body of clypeus with a median carina arising posterior to hyaline border at socket of median clypeal seta, extending posterad and dividing into two carinae that intersect frontoclypeal teeth; posterior border of clypeus carinate; antennae with 13 segments; antennal scapes barely surpassing cephalic margin, shorter than funicular segments I-III combined; funicular segment II > 2X longer than funicular segment I (antennal pedicel); posterior margin of head, in profile, concave; with a median longitudinal carina that originates at occipital carina and extends to level of vertexal tubercles; occipital collar present laterally, short and, in lateral view, quadrate; hypostomal teeth large and rounded at tip. Mesosoma: Pronotum with humeral and lateral tubercles present, short and angulate; median pronotal spines absent, replaced by a transverse carina that connects lateral spines; inferior margin of pronotum evenly rounded; propleuron adjacent to inferior pronotal edge with a low tubercle bearing simple hairs; mesoscutum and scutellum similar to those of gyne, axillary concavities less pronounced; propodeal spines long and dorsolaterally compressed, in lateral view appearing somewhat expanded apically, in dorsal view appearing apically blunt, but in dorsolateral (edge-on) view appearing linear; base of propodeum with a pair of lateral carinae (Rio de Janeiro specimens; carinae absent in Espiritu Santo specimens), declivity with a pair of lamellate carinae (Rio de Janeiro specimens; carinae lower in Espiritu Santo specimens). Metasoma: Petiole pedunculate; in profile, node of petiole low and evenly convex; petiole with dorso-lateral carinae that extend along entire length of petiole, petiolar node with single median (Espiritu Santo specimens) or a few longitudinal carinae (Rio de Janeiro specimens); petiole with a pair of ventral lateral longitudinal carinae extending its entire length; node of petiole 1.6 X longer than wide; node of postpetiole 1.7 X wider than long; abdominal tergite IV finely reticulate. Wings: as in female but lacking fenestra. Forewing length = 4.56-4.68 mm; hind wing length = 3.25-3.47 mm.

Individuals ferruginous in color; antennae and legs testaceous; pilosity on antennal scape simple and appressed; head and mesosoma with hook-like hairs mostly on carinae and tubercles; legs with simple appressed or decumbent hairs; abdominal tergite IV with very short simple appressed hairs.

Type Material
HOLOTYPE. Worker, labeled: “Brazil: Sao Paulo, Botucatu, 29-XI-2002, 23°15’ S 48°15’ W, 825 m., nest series, pasture, (RS Camargo).”. No. 00412647. PARATYPES. Nine workers, same data as holotype. Deposited in (1) USNM ENT No. 00537327; MZSP (3) USNM ENT Nos. 00537318, 00537309, 00413572; and USNM (5) USNM ENT Nos. 00413572, 00413574, 00413577, 00412653, 00412649, 00412651; 1 gyne labeled: “Brasil: Jatai, Goias, Faz. Aceiro, 30-X-1962, Exp. Dep. Zool. Cerrado” (MZSP) USNM ENT No. 00537319; 1 gyne labeled: “Sao Paulo, Botucatu, 5-X-1991, (BH Dietz)” (MZSP) USNM ENT No. 00537310; 2 males labeled: “Brasil: GB [refers to state of Guanabara, actually state of Rio de Janeiro (RJ)], Rio de Janeiro (Floresta da Tijuca), IV-1966, (M. Alvarenga). (MZSP) USNMENT Nos. 00537311, 00537311; 2 males labeled: “Brasil: Espirito Santo, Santa Teresa, XI-1928, (O Conde).” (MZSP) USNM ENT No. 00537320.

Etymology
It gives us great pleasure to name this striking and unusual fungus-growing ant after its discoverer, Roberto S. Camargo.

References based on Global Ant Biodiversity Informatics

 * Sosa-Calvo J., and T. R. Schultz. 2010. Three remarkable new fungus-growing ant species of the genus Myrmicocrypta, with a reassessment of the characters that define the genus and its position within the Attini. Annals of the Entomological Society of America 103: 181-195.