Hylomyrma reginae Kutter, 1977

Ulysséa, Mônica Antunes, 2021, Taxonomic revision of the Neotropical ant genus Hylomyrma Forel, 1912 (Hymenoptera: Formicidae: Myrmicinae), with the description of fourteen new species, Zootaxa 5055 (1), pp. 1-137 : 96-99

Hylomyrma reginae Kutter, 1977

Figures 63 , 64 , 86 (map)

Hylomyrma reginae Kutter, 1977: 85 (W). Holotype: GUYANA: Morabukea , vi.1964, R.M. Watson, RM1964-125, PF4,3 (1W) (CASENT0900392 BMNH(E)1013786) [BMNH] [examined by image]. Paratypes: same data as holotype (1W) [BMNH] [examined]; (2W) [NHMB] [examined].

Diagnosis. Regular to slightly irregular and longitudinal striae on head dorsum diverge towards posterior margin, interspaces between striae smooth; striae crest punctuated; striae on mesosoma assuming multiple directions, interspaces indistinguishable; pronotum posterior region, mesonotum, and metanotal groove region with semielliptical to V-shaped striae; dorsal margin of petiole continuous, convex; subtriangular projection on mesoventral surface of petiole; subpostpetiolar process well-developed, subtriangular; profemur and protibia entirely covered with striation; striation on tergum of first gastral segment restricted to base; sternite striation of first gastral segment covering the laterobasal region.

Redescription. WORKER (n=5, exceptionally, for this species, the measures presented outside the parentheses refer to the paratype examined [NHMB]) ( Fig. 63A–C ): HL 0.94 (0.94–1.09); HW 0.87 (0.87–1.04); ML 0.60 (0.60– 0.70); SL 0.67 (0.67–0.76); MOD 0.17 (0.17–0.26); PNW (0.64–0.72); WL 1.30 (1.30–1.52); PSL 0.25 (0.25–0.32); PL 0.62 (0.62–0.75); PW 0.29 (0.29–0.32); PPL 0.27 (0.27–0.34); PPW 0.30 (0.30–0.38); GL 0.97 (0.97–1.20); TL 4.71 (4.71–5.60); CI 93.33 (93.33–101.96); SI 77.14 (73.07–76.09); OI 20 (20–25). Medium to large-sized. Shiny integument. Brownish body, darker gaster, lighter appendices. Thin and unbranched setae, long to short, suberect to subdecumbent.

Head subquadrate; posterior margin straight to slightly concave at middle. Mandible masticatory margin with 5 teeth. Labial palp 3-articulated; maxillary palp 4-articulated.Anterior margin of clypeus straight medially, with a pair of small teeth laterally; median area of clypeus with 10–12 regular to irregular and longitudinal striae. Fontal triangle with 2 striae. Short scape, not reaching head posterior margin; apical antennomere slightly shorter than previous 3 antennomeres together. Frontal carina slightly concave posterior to antennal socket. Eye drop-shaped, midsized, larger diameter with 11 ommatidia. Longitudinal, regular to slightly irregular striae on head dorsum diverge towards posterior margin, striae with punctuated crests, interspaces smooth, striae. Striation on head lateral and laterodorsal regions converge to mandible insertion; gena striate, 3–4 regular and semicircular striae circumscribe the torulus, not reaching eye margin. Interspaces between striae on head ventral surface distinguishable.

Irregular to regular striae on mesosoma dorsum assuming multiple directions, interspaces indistinguishable; transverse striae on pronotum anterior region (DV) continuing on lateral surface; pronotum posterior region, mesonotum, and metanotal groove region (immediate anterior to transverse carina) with semi-elliptical to V-shaped striae; striae on lateral of pronotum continuing sinuously on mesepisternum and propodeum lateral, and transversely on propodeum. Promesonotal junction and metanotal groove indistinct. Transverse carina inconspicuous. Dorsal margin of mesosoma continuous, convex. Propodeal lobe bidentate, dorsal tooth longer and more acute than the shorter and blunt ventral tooth; dorsal tooth slightly shorter than propodeal spine. Propodeal spine midsized, straight (LV), divergent (DV), sculptured on base. Thin striae of uniform thickness on procoxa; irregular and transverse striae on C2 and C3. Profemur covered with regular and transverse striae. Protibia extensor surface entirely covered with regular and longitudinal striae.

Dorsal margin of petiole continuous, convex; subtriangular projection on mesoventral surface; dorsal and lateral surfaces covered with vermicular striae of variable thickness, interspaces indistinguishable; ventral surface smooth. Regular and longitudinal striae on postpetiole and subpostpetiolar process, interspaces indistinguishable; subpostpetiolar process well-developed, subtriangular.

First gastral segment striation similar to postpetiole striae; short striae on tergum, shorter than postpetiole length; sternite striation covering the laterobasal region.

QUEEN (first description) (n=3) ( Fig. 64A–C ): HL (1.02–1.20); HW (0.98–1.22); ML (0.68–0.80); SL (0.72– 0.88); MOD (0.26–0.32); PNW (0.84–0.98); WL (1.56–1.88); PSL (0.30–0.36); PL (0.75–0.90); PW (0.34–0.40); PPL (0.39–0.40); PPW (0.40–0.46); GL (1.20–1.46); TL (5.63–6.64); CI (94.23–101.66); SI (72.13–74); OI (26– 26.53). Large-sized. Color, pilosity, and some sculpture characters shared with conspecific workers, only slightly larger. Larger diameter of eye with 15 ommatidia. Longitudinal, regular to irregular striae on scutum going from an anterior central point towards transcutal suture, interspaces distinguishable. Longitudinal and mostly regular striae with mostly uniform thickness on anepisternum and katepisternum, interspaces distinguishable. Axilla and scutellum with same sculpture of scutum. Scutoscutellar sulcus inconspicuous. Transverse striae on propodeum (DV). Lateral of mesosoma with irregular striae of variable thickness directed to propodeal spine, interspaces distinguishable. Wings unknown.

MALE Unknown.

Etymology. The specific epithet was named after Regina Pestalozzi , Kutter’s daughter.

Comments. Hylomyrma reginae is unlikely to be confused with any other congener because of its very prominent and subtriangular subpostpetiolar process.

Two specimens collected in Upper Takutu-Upper Essequibo, Guyana (USNMENT00688778, USNMENT00689009) were designated as intercaste because of the larger body measures [HL (1.16); HW (1.16–1.17); ML (0.76–0.78); SL (0.82–0.84); MOD (0.27–0.28); PNW (0.83–0.84); WL (1.64); PSL (0.34–0.35); PL (0.82– 0.85); PW (0.36–0.38); PPL (0.36); PPW (0.40); GL (1.30); TL (6.04–6.09)], and for having one central and inconspicuous ocellus.

Distribution. All known specimens were collected in northern South America ( Brazil, French Guiana, Guyana, and Suriname) ( Fig. 86 ).

Natural history. This species is recorded from tropical rainforests (in the Amazon and in Inselberg forests; primary and secondary forests) at elevations between 60 and 1051 m. Specimens are frequently found in leaf-litter samples, which suggests that nests are located in fallen logs, rotten wood, between leaves, or inside natural cavities of the superficial soil layers. Except for the presence of intercastes, there is no further information available regarding the biology of H. reginae .

Additional material examined (23 workers, 3 queens, 2 intercastes): BRAZIL: AM[Amazonas]: Manaus, Dimona Station, INPA, 100ha Plot, 130m, 60.09414°′W, 2.34121°′S, 16.i.2009, J. Sosa-Calvo, rainforest, leaf litter, Winkler sample, JSC090116-LS05 (1W) (USNMENT00447161) [ USNM] ; same except JSC090116-LS06 (1W) (USNMENT00754291) [ USNM] ; Pres[idente] Figueiredo, Terra-firme, Ig. Poraque , 1°54′57″S, 59°26′94″W, 23/04/94, Mata primária, Arm. De solo, Queiroz col. (1W) [ MPEG] ; Terra Firme, ZF-02, km10, capoeira, 02°34′S, 60°06′W, M.O. de A. Ribeiro coll., 01.viii.1990, capoeira, ZF-2/solo, Extração Kempsom, Camada 1, Reg 18, Prof 0-3.5cm (1W) [ INPA] ; MA[Maranhão]: São Francisco do Brejão , 05°17′19″S, 47°15′01.7″W, 01-09.vi.2005, Silva R.R. & Feitosa R.M. cols., Winkler 1 (2W) (MZHY200) [ MZSP] ; PA[Pará]: Marituba, Mata-Winkler, 1°22′S, 48°20′W, 22.x.2004, Santos J.R.M., 17 (1W) [ CEPLAC] ; Utinga, tract. nr. Belém, BF-19, Aug. 14.1962, P.F. Darlington (1W) [ MZSP] ; same data (1W) [ MCZC] ; RO[Rondônia]: Porto Velho, Área Caiçara, C3P3, 09°26′46.8″S, 64°49′31.1″W, 04-18.ix.2012, Vicente, R.E. & Oliveira, J. cols. (2W) [ DZUP] . FRENCH GUIANA: [Cayenne]: Kaw. Mt., Amazon Nature Lodge , 950′, 52°12.349′W, 4°33.426′N, T. Schultz, U. Mueller, J. LaPolla, 2° forest, leaf litter, Winkler sample, TRS050719-01-LS04 (2W) (USNMENT00537919, USNMENT00537922) [ USNM] ; Nouragues Station, IN2-Inselberg For. , 04°05′N, 52°40′W, ix.2009, winkler, Sarah Groc & al, #5630, IN2 Tr2 W10 (1W) [ MZSP] . GUYANA: [Cuyuni-Mazaruni]: Calm Water Creek, along Essequibo River nr. Bartica , 58°37.16′W, 6°28.06′N, 24.ix.2002, J.S. LaPolla, 1° forest, litter sample, =020923-8, JSL020923-01-LS04 (2W) (USNMENT00442164, USNMENT00442165) [ USNM] ; same except =020923-9, JSL020923-01-LS05 (1W) [ USNM USNMENT00442185 ] ; [Potaro-Siparuni]: Iwokrama For. Res., Whitewater Camp , 60m, 58°50.992′W, 4°43.89′N, 5.xi.2002, J.S. LaPolla et al., 1° forest, litter sample, =021105-1-LS20, JSL021105-01-LS20 (1W 1Q) (USNMENT00413113, USNMENT00413112) [ MZSP] ; same except =021105-1-LS11, JSL021105-01-LS11 (1Q) (USNMENT00412448) [ USNM] ; Upper Takutu-Upper Essequibo: Acarai Mts., nr. New Romeo Camp , 1050m, 58°57.867′W, 1°20.048′N, 14.x.2006, T.R. Schultz, J. Sosa-Calvo, C.J. Marshall, R. Williams, 1° forest, leaf litter, Winkler sample, JSC061014-LS03 (1Q 1I, intercaste covered with gold) (USNMENT00688795, USNMENT00688778) [ USNM] ; same except 1051m, 58°57.885′W, 1°20.095′N, JSC061014-LS05 (1I) (USNMENT00689009) [ USNM] . SURINAME: Sipaliwini: Lely Mts. , 560m, 55°13′48.65W, 4°27′2.45N, 29.x.2005, J. Sosa-Calvo & R. Badal, 1° forest, litter sample, nr. creek, JSC051029-01-LS09 (1W) (USNMENT00446454) [ USNM]; same except JSC051029-01-LS08 (1W) (USNMENT00446434) [ IHVL]; JSC051029-01 - LS05 (1W) (USNMENT00446224) [ USNM]; same data (1W) (USNMENT00446225) [ MCZC]; 619m, 54°45′21.96W, 4°15′10.62N, 26.x.2005 , J. Sosa-Calvo & R. Badal, 1° forest, litter sample, tall forest, rocky soil, JSC051026-01- LS04 (1W) (USNMENT00447161) [ USNM] .

Figures

FIGURE 63. Worker of Hylomyrma reginae (BRAZIL: AM: Terra Firme [INPA]). A) frontal view; B) dorsal view; C) lateral view. Photos by Ricardo Kawada.

FIGURE 64. Queen of Hylomyrma reginae (USNMENT00688795). A) frontal view; B) dorsal view; C) lateral view. Photos by M.A. Ulysséa.

FIGURE 86. Distribution records of Hylomyrma dentiloba, H. macielae, H. reginae, H. villemantae, and H. wachiperi.