Stigmatomma tsyhady

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Stigmatomma tsyhady
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Amblyoponinae
Tribe: Amblyoponini
Genus: Stigmatomma
Species group: tsyhady
Species complex: tsyhady
Species: S. tsyhady
Binomial name
Stigmatomma tsyhady
Esteves & Fisher, 2016

Stigmatomma tsyhady casent0121332 p 1 high.jpg

Stigmatomma tsyhady casent0121332 d 1 high.jpg

Specimen Label

Stigmatomma tsyhady has been collected in gallery forests, littoral forests, montane forests, and rainforests within the limits of the humid forests and subhumid forests ecoregions (sensu Schatz 2000) in the eastern biome of Madagascar (sensu Burgess et al. 2004). Specimens were distributed at elevations ranging from 10 to 1125 m, of which 72 collection events occurred at an elevation lower than 800 m, out of a total of 131 collection events. (Esteves and Fisher 2016)

Identification

Esteves and Fisher (2016) - A member of the tsyhady complex in the tsyhady species group. Stigmatomma tsyhady, Stigmatomma irayhady, Stigmatomma roahady, and Stigmatomma liebe share the presence of genal teeth, palpal formula, presence of fenestra on the subpetiolar process, shape of microtrichia on posterior face of posterior metatibial spur, and absence of stout setae on the apex of hypopygium. Color, size, and presence of two mesotibial spurs make S. irayhady, S. roahady and S. tsyhady even more similar. However, S. tsyhady is distinguished by the absence of a sulcus on the antero dorsal face of its mesobasitarsus, and on the anterior face of its metabasitarsus.

Worker. With characters of the tsyhady species -group and the tsyhady species -complex as described above, and the following characters (asterisks flag unique characters within the genus in the Malagasy bioregion):

1. Integument brown to black; medium- to large -sized ant (HL: 1.04-1.33 , WL: 1.36-1.72).

2. Pairs of teeth along baso -masticatory margin of mandible have the same length along basoapical axis.

3. Spatular setae ventrally skirting baso -masticatory margin of mandible.

4. Dorsal face of the head mostly costulate -foveolate, grading into foveolate posteriorly.

5. Palpal formula 4:3.

6. Pronotum and the dorsal face of remainder mesosoma foveolate; lateral face of remainder mesosoma mostly smooth; propodeal declivitous face foveolate.

7. Mesepisternum divided into anepisternum and katepisternum.

8. Baso ventral half of calcar of strigil lamellar.

9. Anterior face of calcar of strigil with strap -like microtrichia.

10. Two mesotibial spurs.

11. * Absence of a longitudinal sulcus on mesobasitarsus.

12. Two metatibial spurs.

13. Anterior face of posterior spur almost glabrous, with few lanceolate microtrichia; posterior face glabrous.

14. Row of of few stout, paddle-like setae present on the baso-inner face of metabasitarsus.

15. Absence of a longitudinal sulcus on metabasitarsus.

16. Subpetiolar process runs continuously posteriorly, not forming a fin.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -13.26333° to -25.06167°.

   
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

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Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

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Stigmatomma tsyhady occurs in sympatry with S. irayhady at the Binara Forest, with S. roahady in twelve localities (Ambatovy Forest, Analamay Forest, Vevembe Forest, Mantadia National Park, Marojejy National Park, Ranomafana National Park, Zahamena National Park, Andohahela National Park, Andringitra Reserve, Ivohibe special reserve, Anosyenne Mountains, and at the Binara Forest), and with S. liebe in four localities (Andohahela National Park, Andringitra Reserve, Ivohibe Special Reserve, and at the Anosyenne Mountains).

Habitat

Specimens were recorded from sifted leaf mold and rotten wood (119 collection events), Malaise trap (one event), ground foraging (two events), nesting or foraging in the root mat on the ground or on rock (three events and two events, respectively), in a rotten log (one event), and in the soil (two events).

Biology

Castes

Worker

Queen

Male

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • tsyhady. Stigmatomma tsyhady Esteves & Fisher, 2016: 174, figs. 101-114 (w.q.m.) MADAGASCAR.
    • Type-material: holotype worker, 8 paratype workers.
    • Type-locality: holotype Madagascar: Toamasina, Ambatovy, 12.4 km. NE Moramanga, 1080 m., -18.83937, 48.30842, 8.iii.2007, BLF16936, CASENT0121332, montane rainforest, ground forager (B.L. Fisher, et al.); paratypes with same data but CASENT0318425 to -427, 0318440, and 0121349.
    • Type-depositories: CASC (holotype); BMNH, CASC, MHNG, NHMB (paratypes).
    • Distribution: Madagascar.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

(holotype values within parentheses): HL: 1.04-1.33 (1.31); HW: 0.95-1.24 (1.13); HW2: 0.84-1.08 (1.03); SL: 0.59-0.73 (0.73); ML: 0.67-0.94 (0.87); WL: 1.36-1.72 (1.70); PPW: 0.60-0.79 (0.70); PtL: 0.63-0.83 (0.78); PtW: 0.64-0.85 (0.77); CI: 84-93 (86); SI: 55-57 (56); MI: 64-70 (66); PtI: 98-104 (102).

Head: Mandibular baso-masticatory margin skirted dorsally by row of filiform setae; ventrally, by spatular setae. Mandibular dentition arrangement, from base to apex: single larger tooth; much smaller single tooth (absent or much reduced in length in some specimens); five pairs of teeth (each tooth pair with same dimensions, fused basally; pairs of teeth similar in length along basoapical axis of mandible); single preapical tooth; apical tooth. Anterior clypeal margin with eight to nine tubercle-like cuticular processes, arranged in a single row, armed anteriorly with an asymmetrical, mucronate, dentiform seta. Lateral-most clypeal cuticular process with row of smaller conical setae anterolaterally, continuing laterally along clypeal anterior margin, arising from flat cuticle. Median clypeal cuticular processes around 2x the length of associated dentiform setae. Pair of long, filiform setae on anterior clypeal margin bordering the central-most cuticular processes. Median area of clypeus extending posteriorly between antennal sockets; frontoclypeal sulcus round. Supraclypeal area an oval concavity Twelve antennomeres. Genal teeth present. Widest diameter of compound eyes: two to three ommatidia. Palpal formula: 4:3 (four maxillary, three labial).

In dorsal view, lateral margins of mesonotum continuous with posterior remainder of mesosoma, or somewhat expanded laterally. Metanotal suture absent or weakly impressed. Sulcus dividing mesepisternum into anepisternum and katepisternum. Metathoracic spiracle slit -like. Propodeal spiracle round, with swollen margin. Face of propodeal declivity slightly concave.

Legs: Baso ventral half of calcar of strigil lamellar. Anterior face of calcar of strigil with strap -like microtrichia; posterior face with lanceolate microtrichia. Multiple paddle-like setae on antero ventral face of protibial apex, next to calcar of strigil. Multiple paddle -like setae on anterior face of probasitarsus; row of stout setae on posterior face, parallel to comb of strigil. Two mesotibial spurs; simple anterior spur covered with lanceolate microtrichia, posterior spur somewhat falcate (with round baso ventral projection) and covered with lanceolate microtrichia. Ventral margin of posterior mesotibial spur with digitiform cuticular projections, restricted to the basal-most region or along entire ventral margin. Absence of a longitudinal sulcus on the mesobasitarsus. Stout filiform setae along inner face of mesobasitarsus. Two metatibial spurs: simple anterior spur, with lanceolate microtrichia; posterior spur pectinate. Anterior face of posterior spur almost glabrous, with few lanceolate microtrichia; posterior face glabrous. Absence of a longitudinal sulcus on metabasitarsus. Row of few stout, paddle -like setae on the baso-inner face of metabasitarsus. Stout filiform setae on the remainder of inner face of metabasitarsus. Arolium on pro-, meso-, and metapretarsus.

Metasoma: Petiole sessile. Ventroanterior margin of petiolar tergite anterior dorsolatero-ventral carina (Ward 1990) slightly shorter than anterior margin of subpetiolar process, in lateral view. Ventral margin of subpetiolar process running posteriorly in a somewhat continuous line. Presence of a fenestra on the lateral face of subpetiolar process. Petiolar proprioceptor zone a large, round concavity with numerous sensilla. Prora present. Scrobiculate sulcus between pretergite and postergite of abdominal segment III and presclerites and postsclerites of abdominal segment IV. Absence of stout setae on hypopygium.

Sculpture: Mandibular dorsal face mostly costate, except for smooth apical portion. Clypeal median area costate. Supraclypeal area mostly smooth. First third of the head, in dorsal view, mostly costulate -foveolate, grading into foveolate posteriorly. Area posterior to tentorial pit carinate concentrically. Labrum imbricate. Pronotum and dorsal face of mesosoma foveolate. Katepisternum mostly costulate. Metapleuron costate dorsally and posteriorly. Remainder of the lateral face of mesosoma smooth. Face of propodeal declivity foveolate. Petiolar tergite smooth anteriorly, grading into punctate/foveolate-rugulose laterally, and into punctate/foveolate dorsally; laterotergite somewhat imbricate; poststernite alveolate. Abdominal segments III and IV weakly punctate/foveolate; tergites of abdominal segments VI and VII weakly imbricate.

Pilosity and color: Erect to subdecumbent pilosity on head, dorsal face of mesosoma, petiolar tergite, and abdominal segments III, IV, and V. Erect to suberect pilosity on anterior half of petiolar poststernite. Longer pilosity on abdominal segments VI and VII. Body color brown to black; gaster yellow -brown to brown (sometimes sclerites are darkish, grading into yellow -brown to orange towards anterior and posterior margins); appendages yellow - brown to orange.

Character variation: No geographic pattern is seen in the variation seen on Stigmatomma tsyhady, and characters such as body size, the position and size of the smaller basal single tooth on the mandibles, number of dentiform setae on the anterior margin of the clypeus, degree of mesonotum expansion, metanotal suture presence and its degree of development, amount of cuticular projections on the ventral margin of the posterior mesotibial spur, sculpture, and color fluctuate even among specimens collected at the same locality.

Queen

Alate when virgin: similar to the worker caste but for the greater body length, larger compound eyes, presence of ocelli, and differences on the mesosoma due to the presence of wings. Parapsidal lines on the mesoscutum; scuto-scutellar suture narrow, without apparent sculpture on its midsection, but scrobiculate on its apexes. Mesepisternum somewhat divided into anepisternum and katepisternum; anepisternum dispersed foveate; katepisternum costate; mesepimeral lobe not distinct; metapleuron divided into upper and lower sections; upper metapleuron separated from propodeum by wide, costate-dispersed foveate sulcus; lower metapleuron separated from the propodeum by a carina, followed dorsally by a strigate sulcus. Forewing: pterostigma well developed; Rs.f2-3 present; Rs.f5 present and reaching R.f3; 1r-rs absent; 2r-rs, M.f4, 2rs-m, Cu.f2, 1m-cu, and A.f2 present; cu-a intercepting M+Cu anteriorly to the separation point between Cu.f1and M.f1. Hindwing: C indistinct; R present, but indistinct when reaching costal margin; Rs.f2 and 1rs-m present; M.f2 present, but indistinct; Cu, cu-A, and A.f2 present.

Male

Alate: Mandibles falcate, with sharp, single apical tooth. Anterior clypeal margin armed with dentiform setae. Compound eyes with sparse setae present among ommatidia. Palpal formula 4:3. Notauli distinct and scrobiculate; parapsidal lines present; scuto-scutellar suture scrobiculate. Mesepisternum partially divided into anepisternum and katepisternum; posterior oblique sulcus short, not well developed; epimeral lobe well developed; metapleuron divided into upper and lower sections by a pit; scrobiculate sulcus separating upper metapleuron from propodeum; narrower scrobiculate sulcus separating lower metapleuron from propodeum. Forewing: pterostigma well developed; Rs.f2-3 present; Rs.f5 present and reaching R.f3; 1r-rs absent; 2r-rs, M.f4, 2rs-m, Cu.f2, 1m-cu, and A.f2 present; cu-a intercepting M+Cu at the separation point between M.f1 and Cu.f1. Hindwing: C present; R seemingly absent; Rs.f2, M.f2, and Cu present as not well-distinct stubs; 1rs-m and cua present; A.f2 distinct, but short. Pygostyles present. Posterior margin of abdominal segment IX convex. Paramere not visibly divided into telomere and basimere. Digitus tongue-plier-shaped: presence of a comparatively enlarged, but thin basal projection on the digitus; cuspis shorter than digitus. Entire ventral margin of the penisvalva comparatively finely serrate; dorsal portion of the penisvalva sclerotized.

Type Material

Holotype: Madagascar; Toamasina; Ambatovy, 12.4 km NE Moramanga; 1080; -18.83937; 48.30842; coordinates obtained from GPS; General collecting; 03/08/2007; montane rainforest; BLF16936; ground forager(s); 1w; pin; casent0121332; B. L. Fisher et al.; California Academy of Sciences. Paratypes. Same data as holotype. 2w CASC, 1w The Natural History Museum, 1w Naturhistorisches Museum, Basel. Except BLF16939. 1w Musee d'Histoire Naturelle Genève.

Etymology

Combines the Malagasy preposition tsy, meaning absence, and the Malagasy noun hady, meaning sulcus, ditch, or trench. The name tsyhady refers to the absence of longitudinal sulci on the mesobasitarsus and metabasitarsus of this species; such absences together are unique among Stigmatomma species in the Malagasy bioregion.

Determination Clarifications

Amblyopone sp.1 (specimen CASENT0500011) in Saux et al. (2004).

References