Hylomyrma mitiae Ulyssea 2021, new species

Hylomyrma mitiae Ulysséa new species

Figures 53, 54, 80D, 81H, 87 (map)

Holotype: GUYANE FRANÇAISE: [Saint-Laurent-du-Maroni: Maripasoula], Mitaraka Mts, Pente, 2.238226N -54.45203, 04.iii.2015, J. Orivel & F. Petitclerc cols., winkler 48h, A-P2-8, MI15-0380-25 (1W) (MZSP67401) [MZSP]. Paratypes: same data as holotype (3W) [CASC, DZUP, IHVL]; (7W) (MZHY223) [MZSP]; same except Plateau, 2.243615N -54.45882, 03.iii.2015, J. Orivel & F. Petitclerc cols., winkler 48h, A-P1-12, MI15-0344-62 (1W 2Q, one worker and one queen covered with gold) (MZSP67403, MZSP67402, MZSP67404) [MZSP]; (2W) [MCZC, USNM]; Maripasoula, vii.1999, S. Durou (1W) [CEPLAC]; [Cayenne]: Nouragues Natural Reserve Station, 102km SW of Cayenne, lat 4.08799, lon -52.67978, 145m, 21.viii-1.ix.2018, Rainforest, Ant Course 2018 (2W) (MZHY224) [MZSP].

Diagnosis. Vermicular to vermiculated-areolated striae on head dorsum and mesosoma; dorsal margin of petiole continuous, ventral surface smooth; longitudinal and anastomosed striae on postpetiole and tergum of first gastral segment; subpostpetiolar process prominent, subtriangular; profemur posterior surface and protibia extensor surface entirely striate; striae on tergum of first gastral segment shorter than postpetiole length; 2 short branches of equal size diverging from the main axis.

Description. WORKER (n=3) (Fig. 53A–C): HL (0.95–1.06); HW (0.98–1.01); ML (0.67–0.75); SL (0.75–0.83); MOD (0.27–0.29); PNW (0.73–0.76); WL (1.41–1.52); PSL (0.32–0.356); PL (0.69–0.72); PW (0.27–0.30); PPL (0.30–0.32); PPW (0.33–0.36); GL (1.13–1.21); TL (5.27–5.52); CI (94.11–106.45); SI (74.24–81.81); OI (27.27– 28.78). Large-sized. Shiny integument. Dark brown body, lighter appendices. Thin and branched setae, long to midsized, erect to subdecumbent; 2 short branches of equal size diverging from the main axis (Fig. 80D).

Head subquadrate; posterior margin straight. Mandible masticatory margin with 5 teeth. Anterior margin of clypeus concave medially, with a pair of medium teeth laterally; median area of clypeus with irregular and longitudinal striae converging to a point on the anterior margin, interspaces indistinguishable. Frontal triangle with 1 sagittal stria. 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 12 ommatidia. Head dorsum with vermicular to vermiculated-areolated striae, divergent towards posterior margin, interspaces smooth. Striae on head lateral and laterodorsal regions converge to eye margin; very thin striae (microsculpture) between vermicular to vermiculated-areolated striae (macrosculpture), interspaces between microesculpture indistinguishable; gena striate, with the same striation of head lateral, 2–3 regular and semicircular striae circumscribe the torulus, not reaching eye margin. Interspaces between striae on head ventral surface distinguishable.

Thick, vermicular to vermiculated-areolated striae on mesosoma, interspaces between thick striae on mesosoma dorsum smooth, but filled with thinner striae on mesosoma lateral. Promesonotal junction indistinct. Metanotal groove discernible by a slight depression. Transverse carina well-marked. Dorsal margin of mesosoma discontinuous, slightly convex. Propodeal lobe bidentate, dorsal tooth slightly longer and more acute than the shorter and blunt ventral tooth; dorsal tooth length 1 / of propodeal spine length. Propodeal spine long, straight (LV), divergent (DV), 2 sculptured on base. Thin and transverse striae of uniform thickness on procoxa; irregular and transverse striae on C2 and C3. Irregular to regular transverse striae on profemur dorsal and posterior surfaces; anterior and ventral surfaces smooth. Protibia extensor surface entirely striate.

Dorsal margin of petiole continuous, convex; ventral surface smooth; first third of dorsal surface smooth; irregular and transverse striae on second third of dorsal surface (aligned to petiolar spiracle) continuing on lateral surface; vermiculated-areolated striae on lateral and last third of dorsal surface. Longitudinal, regular to irregular striae on postpetiole, few anastomosed; subpostpetiolar process striae restricted to lateral region; subpostpetiolar process prominent, subtriangular.

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

QUEEN (n=2) (Fig. 54A–C): HL (1.04); HW (1.06); ML (0.75–0.76); SL (0.81–0.86); MOD (0.30); PNW (0.89–0.90); WL (1.67–1.69); PSL (0.36); PL (0.73–0.76); PW (0.30–0.32); PPL (0.33–0.36); PPW (0.36–0.40); GL (1.40–1.43); TL (5.96–6.06); CI (95.74–100.97); SI (101.47); OI (28.98). Large-sized. Color, pilosity, and some sculpture characters shared with conspecific workers, only slightly larger. Larger diameter of eye with 16–17 ommatidia. Longitudinal, irregular to vermicular striae on scutum going from an anterior central point towards transcutal suture, interspaces distinguishable. Longitudinal and irregular striae on anepisternum and katepisternum, interspaces distinguishable. Axilla and scutellum with the same sculpture of scutum. Scutoscutellar sulcus inconspicuous. Transverse and regular striae on propodeum (DV). Thick striae (macrosculpture) on mesosoma lateral, irregular to vermiculated-areolated, directed to propodeal spine, interspaces between thicker striae filled with thinner striae (microsculpture). Wings as in Fig. 81H.

MALE Unknown.

Etymology. The epithet mitiae is a Latin noun in the genitive case created by adding the singular Latin genitive case suffix -e to the first name of a female person. This species is named in honor of M.A. Ulysséa’s beloved friend Mítia Heusi Silveira (1984–2010), who had her life interrupted by femicide. As an undergraduate student, she developed projects with Fungi and Coleoptera. After university, she worked at FUNAI, a Brazilian governmental agency for the protection of indigenous interests and culture.

Comments. Hylomyrma mitiae is similar to H. virginiae and H. sagax. All three are allopatric, but nevertheless occur in northwestern South America. Hylomyrma mitiae has been recorded only in French Guiana (Fig. 87), H. sagax is restricted to southeast Colombia (Fig. 83), whereas H. virginiae has been recorded in Ecuador (both sides of The Andes) and in western Colombia (Fig. 89). Hylomyrma mitiae can be distinguished from H. virginiae (characteristic in parentheses) by the comparatively larger body, TL 5.27–5.52 mm, WL 1.41–1.52 mm (vs. smaller, TL 4.94–5.20 mm, WL 1.24–1.40 mm), the gena and laterodorsal region of head are covered with very thin striae between the vermicular to vermiculated-areolated striae (vs. very thin striae superimposed on vermicular to vermiculated-areolated striae), the metanotal groove distinguished by a slight depression (vs. indistinct), the continuous dorsal margin of petiole (vs. discontinuous), and the very prominent and subtriangular subpostpetiolar process (vs. weak and slightly convex). Hylomyrma mitiae is distinguished from H. sagax by the pair of medium sized teeth laterally at the clypeus anterior margin (vs. large teeth), the presence of smooth interspaces between the vermicular striae only on the mesosomal dorsum (vs. on the entire mesosoma), and the subtriangular subpostpetiolar process (vs. convex).

Distribution. This species is only known from French Guiana (Fig. 87).

Natural history. Most specimens were 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.