Mesostruma

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Mesostruma
Mesostruma turneri
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Mesostruma
Brown, 1948
Type species
Strumigenys (Epopostruma) turneri, now Mesostruma turneri
Diversity
9 species
(Species Checklist)

Mesostruma turneri casent0172478 profile 1.jpg

Mesostruma turneri

Mesostruma turneri casent0172478 dorsal 1.jpg

Specimen Label

Evolutionary Relationships
Attini

Ochetomyrmex (2 species), Tranopelta (2 species)




Allomerus (8 species), Blepharidatta (4 species), Diaphoromyrma (1 species), Lachnomyrmex (16 species), Wasmannia (11 species)









Acanthognathus
  (7 species)





Daceton
  (2 species)



Lenomyrmex
  (7 species)





Microdaceton
  (4 species)




Orectognathus
  (29 species)




Colobostruma
  (16 species)




Epopostruma
  (19 species)



Mesostruma
  (9 species)










Acromyrmex (62 species), Apterostigma (44 species), Atta (19 species), Cyatta (1 species), Cyphomyrmex (23 species), Kalathomyrmex (1 species), Mycetophylax (21 species), Mycetagroicus (4 species), Mycetarotes (4 species), Mycetosoritis (2 species), Mycocepurus (6 species), Myrmicocrypta (31 species), Sericomyrmex (11 species), Trachymyrmex (49 species), Xerolitor (1 species)



Basiceros (8 species), Cephalotes (119 species), Eurhopalothrix (53 species), Octostruma (34 species), Phalacromyrmex (1 species), Pheidole (1,141 species), Pilotrochus (1 species), Procryptocerus (45 species), Protalaridris (7 species), Rhopalothrix (16 species), Strumigenys (836 species), Talaridris (1 species)










Based on Ward et al. (2014), Blaimer et al. (2018) and Li et al. (2018).

These uncommon ants form small colonies in soil, usually under or between rocks. They are predacious, foraging primarily on the ground in leaf litter but also occasionally on low vegetation. The genus is restricted to Australia.

Identification

The antennae are 6 segmented (including the scape). The sides of the petiole are rounded while the sides of the postpetiole are either armed with thin, wing-like flanges (best viewed from above) or are rounded.

Workers of Mesostruma are most similar to workers of Colobostruma. They differ in that Mesostruma has wing-like flanges (when present) only on the postpetiole while flanges are present on both the petiole and postpetiole in Colobostruma.

Keys including this Genus

Keys to Species in this Genus

Distribution

World distribution based on political regions. View/Edit Data
Mesostruma Distribution.png Worlddistribution legend.jpg

Species richness

Species richness by country based on regional taxon lists (countries with darker colours are more species-rich). View Data

Mesostruma Species Richness.png

Biology

Heterick (2009) - These attractive little ants are seldom collected, although several species appear to be reasonably common and have been found in bark traps in mixed Wandoo and Jarrah-Marri woodland in south- western Australia. Perhaps the best time to see them is in the evening, night or early morning when they can typically be found foraging on the lower trunks of eucalypts.

Castes

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • MESOSTRUMA [Myrmicinae: Dacetini]
    • Mesostruma Brown, 1948e: 118. Type-species: Strumigenys (Epopostruma) turneri, by original designation.
    • Mesostruma junior synonym of Colobostruma: Baroni Urbani & De Andrade, 1994: 15; Baroni Urbani & De Andrade, 2007: 94.
    • Mesostruma revived status as genus: Bolton, 1995b: 35; Bolton, 1999: 1680; Shattuck, 2000: 47.

Worker

Shattuck (2000) -

With characters of the epopostrumiform genus group......

Palp formula 5 , 3.

Labrum large or very large, forming a massive shield in Colobostruma and Mesostruma that can reflex tightly over the labio-maxillary complex and completely cover the buccal cavity; somewhat smaller in Epopostruma where it covers approximately the apical half of the labio-maxillary complex.

Basimandibular gland bulla absent.

Antenna usually with 4 - 6 segments, rarely more.

Scape, when laid back in its normal resting position , passes below the eye or across the ventral margin of the eye; basal part of scape strongly downcurved.

Scrobe usually present, extending below the eye, the latter not located ventrolaterally on side of head.

Femora and tibiae lack gland bullae on their dorsal surfaces.

Pronotal humeri usually armed.

Metapleural gland with apex of bulla close to or abutting the annulus of the propodeal spiracle.

Propodeal spiracle at about the m idheight of the sclerite, separated from margin of declivity.

Tergite of petiole or postpetiole with lateral cuticular laminar outgrowths; extremely rarely (1 species) with traces of spongiform tissue.

Postpetiolar spiracles ventral.

Limbus absent from first gastral tergite.

Suture separating first gastral tergite and stemite angulate laterobasally; horizontal basal margin of stemite with a raised rim or crest adjacent to the tergite margin , this crest usually continues round the laterobasal angle.

Bizarre pilosity never developed.

......and the following.....

Mandibles elongate triangular, with a larger apical and smaller preapical tooth ; proximal of this the margin is edentate and lamellate. Mandible without an inflected basalexternal angle and not downcurved basally.

Mandibles at full gape open to only 60° - 90° ; with static pressure mode of action.

Basal process of mandible large, truncated apically, located in the same plane as the masticatory margin.

Labrum hypertrophied, forming a massive shield that can reflex tightly over the entire labio-maxillary complex and completely cover the buccal cavity; its apical margin evenly convex , not bilobate.

Trigger hairs present on dorsum of labrum.

Side of head with a vertical preocular groove, this groove not extending onto the ventral surface.

Tergite of petiole without lateral lobes at the node. Tergite of postpetiole with or without lateral laminae or lobes.

References

  • Baroni Urbani, C.; De Andrade, M. L. 1994. First description of fossil Dacetini ants with a critical analysis of the current classification of the tribe (Amber Collection Stuttgart: Hymenoptera, Formicidae. VI: Dacetini). Stuttg. Beitr. Naturkd. Ser. B (Geol. Paläontol.) 198: 1-65 (page 15, Mesostruma junior synonym of Colobostruma)
  • Bolton, B. 1995b. A new general catalogue of the ants of the world. Cambridge, Mass.: Harvard University Press, 504 pp. (page 35, Mesostruma as genus)
  • Bolton, B. 1999. Ant genera of the tribe Dacetonini (Hymenoptera: Formicidae). J. Nat. Hist. 3 33: 1639-1689 (page 1680, Mesostruma as genus)
  • Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 187, Mesostruma as genus in Myrmicinae, Dacetini)
  • Brown, W. L., Jr. 1948e. A preliminary generic revision of the higher Dacetini (Hymenoptera: Formicidae). Trans. Am. Entomol. Soc. 74: 101-129 (page 118, Mesostruma in Myrmicinae, Dacetini; Mesostruma as genus)
  • Brown, W. L., Jr. 1952j. The dacetine ant genus Mesostruma Brown. Trans. R. Soc. S. Aust. 75: 9-13 (page 9, Mesostruma as genus)
  • Fisher, B.L. 2000. The Malagasy fauna of Strumigenys. Pp. 612-696 in: Bolton, B. The ant tribe Dacetini. Mem. Am. Entomol. Inst. 65: 1-1028 (page 47, Mesostruma as genus)
  • Heterick, B. E. 2009. A guide to the ants of South-western Australia. Records of the Western Australian Museum, Supplement 76:1-206. PDF
  • Shattuck, S. O. 2000. Genus Colobostruma. Genus Mesostruma. Genus Epopostruma. Pp. 31-67 in: Bolton, B. The ant tribe Dacetini. Mem. Am. Entomol. Inst. 65: 1-1028 (page 63, worker, queen described)
  • Shattuck, S.O. 2007. New species of myrmicine ants from Western Australia. Zootaxa 1661: 47-53. PDF
  • Taylor, R. W. 1973. Ants of the Australian genus Mesostruma Brown (Hymenoptera: Formicidae). J. Aust. Entomol. Soc. 12: 24-38 (page 25, Mesostruma as genus)