Tetramorium intermedium

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Tetramorium intermedium
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Tetramorium
Species: T. intermedium
Binomial name
Tetramorium intermedium
Hita Garcia, Fischer & Peters, 2010

Tetramorium intermedium P zfmkhym20096113.jpg

Tetramorium intermedium D zfmkhym20096113.jpg

Specimen Label

Collected from forest leaf-litter.

Identification

Tetramorium intermedium can be well distinguished from other species of the complex because it is the only one with an antennal scape of medium length (SI 74 - 81) and head and mesosoma fully packed with widely spaced longitudinal rugae.

A member of the Afrotropical muralti species complex, which is part of the weitzeckeri species group.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Ghana (type locality).


Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Nomenclature

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

  • intermedium. Tetramorium intermedium Hita Garcia, Fischer & Peters, 2010b: 48, figs. 5B, 55-57 (w.) GHANA.

Type Material

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

The new species shows an extraordinary character combination for the muralti complex. Within this complex it is the only species with fully longitudinally rugose head and mesosoma although this character is more typical of the edouardi and weitzeckeri complexes. Another character that divides T. intermedium from the remainder of the muralti complex is the moderately sized antennal scape (SI 74 - 81) that is distinctly longer than in all other muralti complex species that all possess short scapes (SI 63 - 73). This character is also more representative for the other 2 species complexes. A third important character is the shape of the petiolar node which is thickly squamiform (DPeI 179 - 212, LPeI 41 - 45), and not far from being high nodiform, typical for the edouardi complex. Only T. akengense shows a similarly thick petiole but this species cannot be confused with T. intermedium because of its reduced sculpturation. Nonetheless, T. intermedium is considered to belong to the muralti complex because it shares the key diagnostic character, the well-developed antennal scrobe with distinct and sharp margin all around. Taking into consideration the description of T. intermedium it shares more important characters with the muralti complex than with both other complexes.

Description

Worker

HL 0.528 - 0.578 (0.556); HW 0.494 - 0.533 (0.521); SL 0.367 - 0.422 (0.406); EL 0.117 - 0.133 (0.124); PW 0.394 - 0.422 (0.412); WL 0.622 - 0.700 (0.670); PSL 0.133 - 0.161 (0.146); PTL 0.094 - 0.106 (0.099); PTH 0.222 - 0.244 (0.234); PTW 0.178 - 0.211 (0.193); PPL 0.150 - 0.194 (0.170); PPH 0.200 - 0.244 (0.229); PPW 0.222 - 0.256 (0.241); CI 90 - 96 (94); SI 74 - 81 (78); OI 22 - 25 (24); PSLI 24 - 29 (26); PeNI 45 - 50 (47); LPeI 41 - 45 (43); DPeI 179 - 212 (195); PpNI 56 - 61 (58); LPpI 66 - 84 (74); DPpI 126 - 153 (141); PPI 116 - 131 (125) (19 measured).

Head longer than wide (CI 90 - 96). Anterior clypeal margin entire and generally convex. Frontal carinae strongly developed and sinuate, curving down ventrally shortly before posterior margin of head to form the posterior and ventral margins of antennal scrobe. Scrobe well-developed, broad and relatively deep, with distinct sharp margin all around. Antennal scape moderate (SI 74 - 81). Eyes moderate to large (OI 22 - 25), with 7 to 9 ommatidia in longest row. Metanotal groove in profile not impressed. Propodeal spines long and spinose (PSLI 24 - 29). Propodeal lobes small and triangular and acute. Petiolar node thickly squamiform, in dorsal view between 1.8 to 2.1 times wider than long (DPeI 179 - 212) and around 2.2 to 2.5 times higher than long (LPeI 41 - 45). Postpetiole rounded, in dorsal view between 1.2 and 1.5 times wider than long (DPpI 126 - 153); in profile generally around 1.2 to 1.5 times higher than long (LPpI 66 - 84). Mandibles unsculptured, smooth and shiny. Clypeus with 3 unbroken longitudinal rugae. Head longitudinally rugose, generally with 6 widely spaced rugae between frontal carinae, sometimes interrupted or short, antennal scrobe with median longitudinal carina anteriorly running at most to posterior eye level, spaces between rugae and scrobal area unsculptured and shiny. Mesosoma laterally and dorsally longitudinally rugose, too, with 6 or more rugae on dorsum of mesosoma; ground sculpturation smooth and shiny. Petiole, postpetiole, and gaster completely unsculptured, smooth and shiny. All dorsal surfaces with simple, fine, standing hairs. Fine pubescence on tibiae and antennal scapes appressed to subdecumbent. Colour uniformly brown, appendages much lighter brown.

Holotype Specimen Labels

Etymology

The new species is, as noted above, quite unusual in its character combination, and, although a clear member of the muralti complex, shows some tendencies towards the other two species complexes. The species epithet accounts for this intermediate position.

References

  • Hita Garcia, F.; Fischer, G.; Peters, M. K. 2010. Taxonomy of the Tetramorium weitzeckeri species group (Hymenoptera: Formicidae) in the Afrotropical zoogeographical region. Zootaxa 2704:1-90.