Hylomyrma primavesi Ulysséa, 2021

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 : 94-96

Hylomyrma primavesi Ulysséa new species

Figures 62 , 80J , 88 (map)

Holotype: BRAZIL: MG[Minas Gerais]: Santana do Riacho, Serra do Cipó, APA[Environmental Protection Area] Morro da Pedreira , 19°17′50.11″S, 43°35′39.69″W, 1300m, 16.i.2012, campo rupestre, pitfall-solo, T.C. Lana col., Q16-X-V-4[Area code - Xeric environment - Transect number - Point number] (1W) ( MZSP67412 ) [ MZSP]. Paratypes: same data as holotype except abril/2011, Q16-X-VI-2 (1W) ( MZSP67413 ) [ MZSP] ; Q16-X-VI-4 (1I) ( MZSP67414 ) [ MZSP] ; abril/2013, Q16-X-V-4 (1I) ( MZSP67415 ) [ MZSP] ; 19°13′48.89″S, 43°34′35.19″W, 1100m, x.2011, C11-X-I-2 (1I) ( MZSP67416 ) [ MZSP] ; C11-X-I-4 (1I) ( MZSP) [ MZSP 67417 ] ; PARNA[National Park] Serra do Cipó , 19°15′49.92″S, 43°32′04.35″W, 1400m, 25-30.iv.2011, AP-X-III-1, pitfall-solo (1W covered with gold) ( MZSP67418 ) [ MZSP] ; same except AP-X-III-2 (1I) ( MZSP67419 ) [ MZSP] ; AP-X-III-3 (1I) ( MZSP67420 ) [ MZSP] ; jul/2011, AP-X-III-2 (1I) ( MZSP67421 ) [ MZSP] ; AP-X-II-3 (1I) ( MZSP67422 ) [ MZSP] ; x.2011, AP-X-III-4 (2I) ( MZSP67423 , MZHY60) [ MZSP] ; i.2012, AP-X-III-1 (1I) ( MZSP67424 ) [ MZSP] ; AP-X-III-3 (1I) ( MZSP67425 ) [ MZSP] ; AP-X-III-4 (1I) ( MZSP67426 ) [ MZSP] ; iv.2012, AP-X-III-1 (1W) [ DZUP] ; AP-X-III-2 (1W) [ USNM] ; AP-X-III-3 (1I) ( MZSP67427 ) [ MZSP] ; julho/2012, AP-X-III-2 (1W) [ MCZC] ; AP-X-III-4 (1I) ( MZSP67428 ) [ MZSP] ; x.2012, AP-X-III-2 (1I) [ MCZC] ; janeiro/2013, AP-X-III-1 (1I) [ CASC] ; AP-X-III-2 (2I) [ DZUP] ; AP-X-III-3 (2I) [ IHVL, JTCL] ; abril/2013, AP-X-III-3 (1I) [ USNM] ; julho/2013, AP-X-III-4 (1I) [ CASC] .

Diagnosis. Body black; regular striae on head dorsum diverge towards posterior margin; rugose striae on mesosoma and petiole; promesonotal junction and metanotal groove discernible by a slight depression (LV) and altered sculpture (VD); propodeal spine length similar to dorsal tooth of propodeal lobe; dorsal margin of petiole discontinuous; transverse striae on node ventral surface; profemur posterior surface smooth; striae on protibia extensor surface weakly marked; striation on tergum of first gastral segment restricted to base; thick branched setae flattened in its final half, with several branches.

Description. WORKER (n=3) ( Fig. 62A–C ): HL (1.16–1.24); HW (1.06–1.18); ML (0.64–0.72); SL (0.80–0.86); MOD (0.28–0.31); PNW (0.72–0.82); WL (1.34–1.48); PSL (0.18–0.20); PL (0.62–0.68); PW (0.28–0.34); PPL (0.34–0.40); PPW (0.36–0.44); GL (1.22–1.42); TL (5.32–5.78); CI (91.38–97.45); SI (71.30–75.47); OI (26.08– 26.41). Large-sized. Shiny integument. Black body, brownish mandibles, trochanter and tarsus. Mostly thin and unbranched setae, midsized to short, suberect to subdecumbent; thick branched setae flattened in its final half, with several branches, mainly in the postpetiole and gaster ( Fig. 80J ).

Head subquadrate; posterior margin slightly concave at middle. Mandible masticatory margin with 5 teeth. Anterior margin of clypeus straight medially, with a pair of small teeth laterally; median area of clypeus with 7–8 regular, longitudinal and thick striae converging to a point on the anterior margin, interspaces between striae smooth or thinner striae between thicker striae. Frontal triangle with 1 sagittal stria. Short scape, not reaching head posterior margin; apical antennomere length 1 / 4 shorter than previous 3 antennomeres together. Frontal carina straight. Eye drop-shaped, midsized, larger diameter with 13 ommatidia. Regular, longitudinal striae on head dorsum, divergent towards posterior margin, interspaces smooth. Thin, regular to irregular striae on head lateral and laterodorsal region near eye, interspaces indistinguishable; striae on laterodorsal region near eye converging to mandible insertion region; striae on lateral region converging to eye margin; laterodorsal region near frontal carina rugose; gena striate, 2–3 regular and semicircular striae circumscribe the torulus, not reaching eye margin. Interspaces between striae on head ventral surface distinguishable.

Mesosoma mostly covered with rugose striae of uniform thickness; interval between striae smooth; transverse striae on propodeum dorsum and on slope surface. Promesonotal junction and metanotal groove discernible by a slight depression (LV) and altered sculpture (DV). Transverse carina indistinct to inconspicuous. Dorsal margin of mesosoma slightly discontinuous, convex. Propodeal lobe bidentate, dorsal tooth slightly longer and acute than shorter and blunt ventral tooth; dorsal tooth length similar to propodeal spine length. Propodeal spine short, straight (LV), divergent (DV), sculptured. Transverse striae of uniform thickness on procoxa; irregular and transverse striae on C2 and C3. Transverse striae on profemur anterior, dorsal and posterior surfaces; ventral surface smooth. Protibia extensor surface entirely striate.

Dorsal margin of petiole discontinuous. Subtriangular projection on petiole mesoventral surface. Node with transverse striae on ventral and anterior surfaces, with interspaces distinguishable; rugose striae on dorsal and latero-dorsal surfaces, interspaces sculptured; irregular and longitudinal striae on latero-ventral surface. Postpetiole and subpostpetiolar process with regular and longitudinal striae; subpostpetiolar process weak, convex.

First gastral segment striation similar to postpetiole striae; striae on tergum as long as postpetiole length; sternite striation restricted to laterobasal region.

QUEEN Unknown.

MALE Unknown.

Etymology. The epithet primavesi is a non-Latin proper noun used in apposition. This species is named in honor of Ana Maria Primavesi (1920–2020), an agronomist, pioneer in soil sciences and especially in the ecological management of tropical soils in Brazil. She provided the scientific basis for the development of tropical organic agriculture.

Comments. Hylomyrma primavesi is unique among its congeners in its blackish body. Nonetheless, its body sculpture resembles that of H. balzani . Hylomyrma primavesi can be distinguished from H. balzani (characteristic in parentheses) by the larger body, TL 5.32–5.78 mm, WL 1.34–1.48 mm (vs. smaller, TL 4.27–5.23 mm, WL 1.10–1.39 mm), the distinct promesonotal junction and metanotal groove (vs. both indistinct). Both species occur in Brazil, whereas H. primavesi is known only from higher elevations in Serra do Cipó, MG ( Fig. 88 ), H. balzani has a broad distribution, occurring mainly in eastern portions of Brazil from north to south ( Fig. 84 ).

Half of all specimens examined have a central ocellus (n=6) or a more or less pronounced depression on the region where winged queens present the central ocellus (n=11). Moreover, most of the specimens have the promesonotal junction and metanotal groove distinguishable by a slight depression or altered sculpture. This morphological variation is associated with intercastes at least in other Hylomyrma species with intercastes. Winged queens are not known in this species, thus these intercastes may perform reproduction. Specimens identified as workers do not present ocelli or ocellar depression, nor the conspicuous promesonotal junction and metanotal groove. One of the workers studied presents the laterals of the mesosoma flattened. This was interpreted as a deformity.

Distribution. This species is only known from Santana do Riacho ( Serra do Cipó National Park and APA Morro da Pedreira), Minas Gerais, Brazil ( Fig. 88 ).

Natural history. All specimens were collected with winkler extractors and pitfall traps at elevations between 1100 and 1400 m in areas of “Campos rupestres”. Those relatively high-elevation areas are characterized by savannas and grasslands, with plants and outcrops. Except for the presence of worker-like intercastes, there is no further information available regarding the biology of H. primavesi . The winged queen of this species is unknown, then perhaps the specimens determined here as intercastes are responsible for reproduction.

Additional material examined (2 workers, 4 intercastes, 2 indeterminates): BRAZIL: MG[Minas Gerais]: Santana do Riacho, Serra do Cipó, APA Morro da Pedreira , 19°17′50.11″S, 43°35′39.69″W, 1300m, 16.i.2012, campo rupestre, pitfall-solo, T.C. Lana col., Q16-X-III-2 (1W, bad mesosoma formation; 1 indet., without head) [ MZSP]; same except jul/2011, Q16-X-VI-4 (1W, without postpetiole and gaster) [ MZSP]; out/2011, Q16-X-III-4 (1 indet.) [ MZSP], Q16 - X-VI-2 (1I) [ MZSP]; PARNA Serra do Cipó , 19°15′49.92″S, 43°32′04.35″W, 1400m, abril/2013, AP-X-III-3, pitfall-solo (1I) [ MZSP]; same except janeiro/2013, AP-X-III-3 (1I) [ JTLC]; julho/2012, AP-X-III-1 (1I) [ MZSP] .

Figures

FIGURE 62. Holotype worker of Hylomyrma primavesi (MZSP67412). A) frontal view; B) dorsal view; C) lateral view. Photos by Gabriel Biffi.

FIGURE 80. Types of setae found in the species of Hylomyrma. Unbranched setae: A) Hylomyrma adelae, H. blandiens, H. macielae; B) H. immanis; C) H. marielleae. Branched setae: D) H. dentiloba, H. lispectorae, H. mitiae, H. peetersi, H. virginiae; E) H. balzani, H. lopesi; F) H. blandiens, H. jeronimae, H. versuta; G) H. dolichops; H) H. transversa; I) H. longiscapa; J) H. balzani, H. lopesi, H. primavesi, H. reitteri, H. versuta; K) H. plumosa.

FIGURE 84. Distribution records of Hylomyrma balzani, H. blandiens, H. jeronimae, and H. lispectorae.

FIGURE 88. Distribution records of Hylomyrma immanis, H. mariae, H. primavesi, and H. versuta.