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Species: Strumigenys chilo   Fisher, 2000 

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Taxonomic History (provided by Barry Bolton, 2016)

Strumigenys chilo Fisher, 2000: 651, figs. 391, 415 (w.q.) MADAGASCAR. Malagasy. "Madagascar, Toamasina, 5.3 km SSE Ambanizana, Andranobe, -15.67133, 49.97395, 425 m, rainforest, sifted litter, 21.XI.1993, coll. Fisher, BLF00926." Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA (MCZC) . CASENT0005509. AntCat AntWiki


Region: Madagascar

Taxonomic Treatment (provided by Plazi)

Treatment Citation: Bolton, B., 2000, The ant tribe Dacetini. With a revision of the Strumigenys species of the Malgasy Region by Brian L. Fisher, and a revision of the Austral epopostrumiform genera by Steven O. Shattuck., Memoirs of the American Entomological Institute 65, pp. 1-1028

Strumigenys chilo FisherHNS sp. n. (Figs 391, 415)

HOLOTYPE WORKER. TL 3.2, HL 0.80, HW 0.61, CI 76, ML 0.45, MI 56, SL 0.56, SI 92, PW 0.33, AL 0.82. Characters of chilo-complex. Mandibles almost straight and at full closure parallel. Apical fork of mandible subtended by a third, shorter spiniform tooth; the fork effectively 3 - dentate; without intercalary teeth or denticles. Preapical teeth absent. Upper scrobe margin ends anterior of preocular groove; when viewed in profile, upper scrobe margin curves downwards at anterior margin of vertical preocular groove of side of head and forms a carina that almost meets preocular lamina; scrobe margin does not extend across dorsal apex of preocular groove so that the latter extends uninterrupted to the cephalic dorsum. Eye large, convex, and plainly visible in full-face view. Dorsum of head sharply depressed behind middorsum, forming a very shallow concave impression before occipital angles; in profile, outline of dorsal margin of occipital corners almost flat. Scape long and slender, approximately straight, the leading edge with a row of slender hairs which are slightly flattened or spoon-shaped apically. Cephalic dorsum with inconspicuous curved fine ground-pilosity; the upper scrobe margin without a row of hairs. Cephalic dorsum with 4 simple standing hairs arranged in a transverse row close to the occipital margin. Dorsum of head reticulate-punctate. Pronotum without standing hairs. Mesonotum with one pair of stout standing remiform to narrowly clavate hairs on anterior margin. Propodeum with one or two pairs of short, fine, posteriorly curved hairs immediately anterior of propodeal spines or on the basal third of the spines. Ground-pilosity on alitrunk as on head but sparser. With the alitrunk in profile the posterior portion of the mesonotum sharply depressed, the metanotal groove represented by a shallow impression. Pronotal humeri rounded to bluntly marginate. Lateral margin of posterior pronotum bluntly marginate. Anterior mesonotum without a narrow carina above the mesothoracic spiracle. Propodeal spines slender, almost spiniform; length of spines about equal to distance between base of spines, distance between base of spines measured distal to basal curvature; propodeal lamella absent. Alitrunk dorsum and sides reticulate-punctate. Petiole node in dorsal view reticulate-punctate and much longer than broad. Postpetiole disc reticulatepunctate. Spongiform appendages of petiole absent, extremely reduced on postpetiole but the latter with a spongiform collar. Basigastral costulae fine to superficial across base of gaster without a central clear area; gaster smooth and shiny where clean. Dorsal surfaces of petiole and postpetiole each with a pair posteriorly projecting stout hairs; gaster with stout standing hairs which are weakly swollen apically. Colour dull yellow to light brown.

PARATYPE WORKERS. TL 3.4 - 3.6, HL 0.85 - 0.90, HW 0.61 - 0.68, CI 71 - 77, ML 0.50 - 0.52, MI 58 - 60, SL 0.62 - 0.65, SI 94 - 103, PW 0.34 - 0.37, AL 0.89 - 0.96 (4 measured). As holotype.

Holotype worker, Madagascar: 5.3 km. SSE Ambanizana, Andranobe, 15 ° 40 ' S, 49 ° 58 ' E, 425 m., 21. xi. 1993, sifted litter (leaf mold, rotten wood), rainforest, # 926 (23) - 10 (B. L. Fisher) (MCZ). Paratypes. 2 workers with same data as holotype but coded (27) - 8, (11) - 6; 2 workers and 1 queen (dealate) with same data as holotype but labeled 25. xi. 1993, ex rotten log, rainforest, and coded # 961 (BMNH, SAM).

NON-PARATYPIC MATERIAL EXAMINED. Madagascar: Nosy Mangabe, 150 m. (P. S. Wird); Mangabi I. (W. L. & D. E. Brown); 6.3 km. S Ambanizana, Andranobe, 25 m. {B. L. Fisher); 1 km. W Andampibe, Cap Masoala, 125 m. (G. D. Alpert); 2 km. W Andampibe, Cap Masoala, 125 m. (Alpert et al.); 10 km. NNE Fenoarivo Atn., S. F. Tampolo, 10 m. (B. L. Fisher); F. C. Didy 960 m. (H. J. Ralsirarson); F. C. Andrianantantely 530 m. (H. J. Ralsirarson); P. N. Mantadia 895 m. (H. J. Ratsirarson); F. C. Sandranantitra 450 m. (H. J. Ralsirarson); Perinet (W. L. Brown); 6 km. ESE Andasibe, 900 m. (P. S. Ward); Rte d'Anosibe, Km. 33 (A. Peyrieras); 7 km. W Ranomafana, 900 m. (WE. Steiner); Ranomafana Mieranony Village (G. D. Alpert); 43 km. S Ambalavao, Res. Andringitra, 825 m. (B. L. Fisher); 7.5 km. ENE Ivohibe, 900 m. (S. Razafimandimby); 9.0 km. NE Ivohibe, 900 m. (S. Razafimandimby); 10 km. NW Enakara, Res. Andohahela, 430 m. (B. L. Fisher); 6 km. SSW Eminiminy, Res. Andohahela, 330 m. (P. S. Ward); 6 km. SSW Eminiminy, Res. Andohahela, 330 m. (Alpert el al.); 6 km. SSW Eminiminy, Res. Andohahela, 250 m. (WE. Steiner); 2.7 km. WNW 302 ° Ste Luce, 20 m. (B. L. Fisher); Mandena, 8.4 km. NNE 30 " Tolagnaro, 20 m. (B. L. Fisher).

The non-paratypic material shows greater size variation than the type-series alone: HL 0.68 - 0.97, HW 0.50 - 0.72, CI 71 - 79, ML 0.40 - 0.55, MI 56 - 63, SL 0.47 - 0.67, SI 91 - 106 (12 measured), but otherwise matches all critical diagnostic characters.

S. chiloHNS is widely distributed in Madagascar rain forests and forms a close species pair with bibiolonaHNS within the grandidieri-group. They both have the mandibular apical fork subtended by a shorter third tooth, and the scrobe margin does not extend across the dorsal apex of the preocular groove so that the latter extends uninterrupted to the cephalic dorsum.

S. chiloHNS is easily differentiated from bibiolonaHNS by the following characters:

1 Dorsum of head sharply depressed behind middorsum, forming a very shallow concave impression before occipital angles; in profile, outline of dorsal margin of occipital corners almost flat.

2 Propodeal spines shorter, length of spine about equal to distance between bases of spines, where distance between bases of spines is measured distal to basal curvature.

Specimen Habitat Summary

Found most commonly in these habitats: 90 times found in rainforest, 19 times found in montane rainforest, 7 times found in littoral rainforest, 2 times found in transition humid forest, 2 times found in montane forest, 3 times found in lowland rainforest, 1 times found in montane rainforest, marsh edge, 2 times found in littoral forest on sandy soil, 1 times found in rainforest, transition to montane forest, 2 times found in forest, ...

Collected most commonly using these methods or in the following microhabitats: 8 times 9 MaxiWinks, mixed samples, 14 times MW 50 sample transect, 5m, 10 times MW 25 sample transect, 5m, 6 times 03 MaxiWinks, mixed samples, 2 times 8 maxi winks, 3 times MW, 25 sifted litter, 4 times Malaise trap, 3 times 9 Maxi winklers, 2 times 10 maxi winks, 1 times 7 MaxiWinks, 1 times 9 maxi winks, ...

Elevations: collected from 10 - 1100 meters, 583 meters average

Type specimens: Holotype of Strumigenys chilo: casent0005509; paratype of Strumigenys chilo: casent0900698

(-1 examples)

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