Anillidris bruchi

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Anillidris bruchi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dolichoderinae
Tribe: Leptomyrmecini
Genus: Anillidris
Species: A. bruchi
Binomial name
Anillidris bruchi
Santschi, 1936

Anillidris bruchi is known from limited number of collections in Brazil and Paraguay. The workers are one of the most unusual in the subfamily, and are very similar to the formicine genus Acropyga. The morphological similarity of the Anillidris worker to workers of Acropyga is presumably a convergence caused by similar hypogeic habits (Shattuck 1992). A recent collection of this species (Schmidt et al 2013) was made in a hypogaeic pitall trap placed 50 cm below ground. This record confirms this ant lives a subterranean existence and greatly extends its known range. Schmidt et al. speculated A. bruchi could be found throughout the vast Paranaese phytogeographic province, which includes seasonal semidediduous rainforest habitats where this ant has been found.

Identification

Shattuck (1992) - (the following generic diagnosis is applicable for this Anillidris bruchi, the only species of the genus) Worker: Frontal lobes very close together; central region of clypeus raised, with a distinct medial trough and lateral ridges; compound eyes absent; palp formula 2:3; entire body covered with dense, short, erect pubescence. Known only from Argentina and Brazil. Queen: Palp formula 3:4; anterior clypeal margin with about 22 erect hairs. Male: Palp formula 3:4; mandible with 6 to 7 teeth, 1 denticle, and a distinct basal angle; fore wing with 2 closed cubital cells and 1 closed discoidal cell.

Distribution

Schmidt et al. (2013) - Dr. Alex Wild kindly warned us about a problem with Kusnezov's 1953 record of Anillidris from Loreto, Argentina. According to Dr. Wild this record appears to be based on a misidentification of a male ant which probably belongs to the Linepithema iniquum or L. neotropicum group. This specimen is imaged at ANTWEB (2012) and an examination of these images clearly shows that this male is considerably different from the Anillidris male described by SHATTUCK (1992) as well as the male imaged in the present paper.

Latitudinal Distribution Pattern

Latitudinal Range: -20.865° to -27.336353°.

   
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina (type locality), Paraguay.

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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Biology

Little is known about the habits of Anillidris. A colony has been collected under a large rock (Borgmeier 1937), while other data suggests that they are subterranean in moist areas (Kusnezov 1953b) and lestobiotic (Santschi 1937). The largest collection of workers was taken from a buried pitfall trap (Schmidt et al. 2013).

Schmidt et al. (2013) report that workers of Anillidris bruchi were collected on 13.IV.2012 by the F.A. Schmidt, F.M. Rezende and R.S. Jesus, using a hypogaeic pitfall trap (SCHMIDT & SOLAR 2010) in a semideciduous rainforest remnant (20° 47' 54.4" S, 42° 50' 53.2" W) in Viçosa, Minas Gerais, southeastern Brazil. This remnant is locally known as "Mata do Seu Nico" and is on a cattle farm and surrounded by a large extension of pasture.

After sampling Anillidris bruchi at Viçosa, we checked for further records of the species in the Neotropical region in addition to those previously reported in the literature (SANTSCHI 1936, 1937, BORGMEIER 1937, KUSNEZOV 1953). We found specimens of A. bruchi deposited in the myrmecological collection of the Museu de Zoologia da Universidade de São Paulo (MZSP), Brazil, which holds the most representative ant collection for the Neotropical region, including the cotypes and Santa Catarina specimens (BORGMEIER 1937) of A. bruchi.

Besides finding Anillidris bruchi in Minas Gerais, we observed that in addition to the Santa Catarina specimens (Figs. 2 - 3) there is a gyne in the MZSP collected from Cotia, São Paulo state, also in southeastern Brazil (28.VIII. 1961, Rabello col., unpubl.) (Fig. 4). These specimens of A. bruchi from São Paulo and Minas Gerais states are the first records of this ant in southeastern Brazil and extend its geographic distribution by some 1,500 - 2,000 km north-east (Fig. 4).

Castes

  • Worker of Anillidris bruchi from Viçosa, Minas Gerais state, southeastern Brazil. A: head in full-face view, B: body in dorsal view, C: body in profile (Fig. 1 from Schmidt et al., 2013).
  • Gyne of Anillidris bruchi from Seara, Santa Catarina state, southern Brazil. A: head in full-face view, B: body in dorsal view, C: body in profile (Fig. 2 from Schmidt et al., 2013).
  • Male of Anillidris bruchi from Seara, Santa Catarina state, southern Brazil. A: head in full-face view, B: body in dorsal view, C: body in profile (Fig. 3 from Schmidt et al., 2013).

Nomenclature

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

  • bruchi. Anillidris bruchi Santschi, 1936d: 414, figs. 21-28 (w.) ARGENTINA (Misiones).
    • Santschi, 1937c: 69 (q.m.).
    • Combination in Linepithema: Kempf, 1972a: 135;
    • combination in Anillidris: Shattuck, 1994: 3.
    • Status as species: Borgmeier, 1937b: 251; Santschi, 1937c: 69; Kutter, 1968b: 205; Kempf, 1972a: 135; Shattuck, 1994: 3; Bolton, 1995b: 63; Wild, 2007b: 23; Schmidt, F.A. et al. 2013: 26.

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

Description

Shattuck (1992):

Shattuck-1992 Figs 1-5.jpg

Worker

HEAD. Vertex weakly convex. Compound eyes and ocelli absent. Antennae 12 segmented. Scape short, surpassing the vertex by less than one-third its length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin entire, without a central notch or concavity of any type. Anterior clypeal setae about 4; short, less than twice the maximum scape diameter; moderately curved ventrally. Posterior clypeal margin even with or posterior to the posterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Frontal carina present. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. Psammophore absent. MOUTHPARTS. Palp formula 2:3 (Santschi 1936). Mandible with 4 teeth and 3 denticles. Apical tooth subequal in length to the subapical tooth. Basal angle distinct, with a well developed tooth or angle separating the masticatory and basal margins. Basal margin smooth and without teeth or denticles. M ESOSOMA. Posteroventral pronotum lateral, rounded. Mesopleural process absent. Declivitous face of propodeum weakly convex; dorsal face convex, subequal in length to the declivitous face. Propodeal angle distinct. Mesosomal spines and tooth absent. Erect pro notal hairs numerous; very short, less than the maximum scape width. Dorsal promesonotal junction with the pronotum and mesonotum even. Metanotal groove reduced to a suture and with the mesonotum and propodeum forming a continuous, uninterrupted surface. Metanotal spiracle lateral and ventral of the dorsal surface when viewed in lateral profile. Propodeal spiracle lateral and ventral of the propodeal dorsum. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). PETIOLE. Scale present; ridged and with a distinct angle dorsally; strongly inclined anteriorly and with the anterior face much shorter than the posterior face. Venter with a slight or weakly developed lobe. GASTER. First tergite damaged in available material. Fifth tergite ventral, gaster with 4 apparent tergites. GENERAL CHARACTERS. Worker caste monomorphic. Chromosome number unknown. Integument thin and flexible, weakly sculptured.

Queen

HEAD. Vertex weakly convex. Compound eyes relatively anterior on head. Antennae 12 segmented. Scape short, surpassing the vertex by less than one half scape length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin entire, without a central notch or concavity of any type. Anterior clypeal setae about 22; short, less than twice the maximum scape diameter; straight. Posterior clypeal margin even with or posterior to the posterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire.

Santschi 1936 Anillidris bruchi fig 21-28.jpg

Psammophore absent. MOUTHPARTS. Palp formula 3:4 (Santschi 1936). Mandible with 8 teeth and no denticles. Apical tooth slightly longer than the subapical tooth. Basal angle distinct, with a well developed tooth or angle separating the masticatory and basal margins. Basal margin smooth and without teeth or denticles. MESOSOMA. Posteroventral pronotum lateral, rounded. Episternal suture complete. Mesopleural process absent. Axilla parallel (very narrow across dorsal surface) and entire. Anterior axillar suture straight. Declivitous face of propodeum convex; dorsal face convex, subequal in length to the declivitous face. Propodeal angle indistinct. Propodeal suture absent. Mesosomal spines and tooth absent. Erect mesoscutal hairs absent. Propodeal spiracle lateral and ventral of the propodeal dorsum. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). WINGS. Radial cell closed. Fore wing with 2 cubital and 1 discoidal cell. Hind wing with 2 cells. PETIOLE. Scale present; ridged and with a distinct angle dorsally; vertical and not inclined anteriorly. Venter with a slight or weakly developed lobe. GASTER. First segment vertical and not concealing the petiole in dorsal view and with a groove or indentation for the reception of the basal portion of the petiole. Fifth tergite ventral, gaster with 4 apparent tergites. Gastral compression absent (gaster circular in cross section). Fourth sternite flat across entire posterior border.

Male

HEAD. Inner margin of eye entire, flat. Scape length shorter than the length of funicular segments 2+3. First funicular segment barrel-shaped. Second funicular segment cylindrical, straight. Funicular segments 2 and 3 at most twice as long as broad. Third and fourth funicular segments straight. Anteromedial clypeal margin entire, without a central notch or concavity of any type. Anterior clypeal setae 6; short, about as long as the maximum diameter of the scape; straight. Posterior clypeal margin between the anterior and posterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. MOUTHPARTS. Palp formula 3:4 (Santschi 1936). Mandible with 6-7 teeth and 1 denticle. Apical tooth slightly longer than the subapical tooth. Basal angle distinct, with a well developed tooth or angle separating the masticatory and basal margins. Basal margin smooth and without teeth or denticles. MESOSOMA. Posteroventral pronotum lateral, rounded. Episternal suture present, complete. Axilla parallel and entire. Anterior axillar suture straight. Declivitous and dorsal faces of propodeum convex. Propodeal angle indistinct. WINGS. Radial cell closed. Fore wing with 2 cubital and 1 discoidal cell. Pterostigmal appendage absent. Hind wing with 2 cells. PETIOLE. Scale present; ridged and with a distinct angle dorsally; vertical and not inclined anteriorly. Venter with a we" developed lobe. Attachment to gaster broad. GASTER. First segment elongated posteriorly, smooth and without a groove or indentation. GENITALIA. Pygostyles present. Posterior margin of subgenital plate with a 'V" -shaped notch. Paramere entire. Digitus linear, with a slight ventral arch. Ventral lobe of volsella present as concave lobe.

Type Locality

Loreto, Misiones Prov., Argentina.

References

References based on Global Ant Biodiversity Informatics

  • Baroni Urbani C. 1977. Katalog der Typen von Formicidae (Hymenoptera) der Sammlung des Naturhistorischen Museums Basel (2. Teil). Mitt. Entomol. Ges. Basel (n.s.) 27: 61-102.
  • Cuezzo, F. 1998. Formicidae. Chapter 42 in Morrone J.J., and S. Coscaron (dirs) Biodiversidad de artropodos argentinos: una perspectiva biotaxonomica Ediciones Sur, La Plata. Pages 452-462.
  • Kusnezov N. 1956. Claves para la identificación de las hormigas de la fauna argentina. Idia 104-105: 1-56.
  • Santschi F. 1936. Fourmis nouvelles ou intéressantes de la République Argentine. Revista de Entomologia (Rio de Janeiro). 6: 402-421.
  • Santschi F. 1937. Les sexués du genre Anillidris Santschi. Bulletin de la Société Entomologique de France. 42: 68-70.
  • Schmidt F. A., R. M. Feitosa, F. de Moraes Rezende, and R. Silva de Jesus. 2013. News on the enigmatic ant genus Anillidris (Hymenoptera: Formicidae: Dolichoderinae: Leptomyrmecini). Myrmecological News 19: 25-30.
  • Shattuck S. O. 1994. Taxonomic catalog of the ant subfamilies Aneuretinae and Dolichoderinae (Hymenoptera: Formicidae). University of California Publications in Entomology 112: i-xix, 1-241.
  • Ulyssea M.A., C. E. Cereto, F. B. Rosumek, R. R. Silva, and B. C. Lopes. 2011. Updated list of ant species (Hymenoptera, Formicidae) recorded in Santa Catarina State, southern Brazil, with a discussion of research advances and priorities. Revista Brasileira de Entomologia 55(4): 603-–611.
  • Vittar, F. 2008. Hormigas (Hymenoptera: Formicidae) de la Mesopotamia Argentina. INSUGEO Miscelania 17(2):447-466
  • Wild, A. L. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.