Polyrhachis andrei

AntWiki: The Ants --- Online
Polyrhachis andrei
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Camponotini
Genus: Polyrhachis
Subgenus: Myrma
Species group: militaris
Species: P. andrei
Binomial name
Polyrhachis andrei
Emery, 1921

Polyrhachis andrei casent0250043 p 1 high.jpg

Polyrhachis andrei casent0250043 d 1 high.jpg

Specimen Labels

Workers of Polyrhachis andrei have only recently been described. One worker was collected in a pitfall trap from primary forest in the Naira region of the Democratic Republic of Congo.

Identification

Rigato (2016) - A distinctive militaris group species with six petiolar spines or teeth and eyes placed at or just in front of the midlength of the head sides.

Emery’s (1921) description and figures of a queen are sufficient to identify this species. Polyrhachis andrei and Polyrhachis decemdentata are the only known African species with six petiolar spines or teeth. P. andrei has sparse, stiff standing hairs mostly apically located on tibiae and scapes, whereas P. decemdentata has abundant, thin hairs uniformly distributed on legs and scapes.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -2.28617° to -2.28617°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun (type locality), Congo, Ghana, United Republic of Tanzania.

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

Castes

Queen

Images from AntWeb

Polyrhachis andrei casent0905622 h 1 high.jpgPolyrhachis andrei casent0905622 p 1 high.jpgPolyrhachis andrei casent0905622 p 2 high.jpgPolyrhachis andrei casent0905622 d 1 high.jpgPolyrhachis andrei casent0905622 l 1 high.jpg
Syntype of Polyrhachis andreiQueen (alate/dealate). Specimen code casent0905622. Photographer Will Ericson, uploaded by California Academy of Sciences. Owned by MSNG, Genoa, Italy.
Polyrhachis andrei casent0906824 h 1 high.jpgPolyrhachis andrei casent0906824 p 1 high.jpgPolyrhachis andrei casent0906824 p 2 high.jpgPolyrhachis andrei casent0906824 d 1 high.jpgPolyrhachis andrei casent0906824 l 1 high.jpg
Queen (alate/dealate). Specimen code casent0906824. Photographer Michele Esposito, uploaded by California Academy of Sciences. Owned by NHMUK, London, UK.

Nomenclature

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

  • andrei. Polyrhachis (Myrma) andrei Emery, 1921e: 22, fig. 1 (q.) CAMEROUN. See also: Bolton, 1973b: 298.

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

Description

Worker

Rigato (2016) - (n=1). HL 1.63, HW 1.33, CI 82, SL 1.58, SI 119, FW 0.63, FI 47, PW, 1.30 WL 2.08, HTL 1.78.

Head somewhat rectangular, side subparallel and weakly convex; posterior corners broadly rounded. Anterior clypeal border with its median third straight and almost lobe-like. Frons relatively wide. Eyes protruding and placed slightly in front of the midlength of head sides. Mesosoma entirely laterally marginate; the margination overhanging the sides. Promesonotal and metanotal groove distinct, especially the latter which is also clearly incised in lateral view. Pronotum, mesonotum and propodeum wider than long. Pronotum with anterolaterally directed strong teeth at its anterior corners. Propodeal dorsum bearing at its posterior corners a pair of very stout upturned and weakly outward directed spines. Propodeal dorsum and declivity mostly confluent. Petiolar node with a pair of strong teeth medially and two pairs of long, mostly straight spines laterally. The spines of each lateral pair diverge: the anteriormost spine is slightly in front and dorsolaterally directed, the posteriormost one arises from a lower point and is more backward tilted.

Mandibles finely reticulate-punctate with overlaying weak striolation and several hair-bearing pits. Clypeus superficially shagreened with sparse hair pits. Head dorsum mostly longitudinally rugose, the rugae posteriorly diverging; around the eyes the sculpturation is mainly reticulate-rugose. Dorsum of mesosoma longitudinally rugose. Mesosoma laterally reticulate-rugose with a more longitudinal pattern on pronotal and propodeal sides. Petiole roughly reticulate. Gaster finely reticulate-punctate and moderately shining.

Standing, yellowish stiff hairs occur sparsely all over the body. Identical, subdecumbent hairs occur also on the apical half of scapes, tibiae and mid- and hind-femora. Pubescence very short and inconspicuous.

Body and appendages black.

Queen

Rigato (2016) - (n=2). HL 1.72–1.89, HW 1.32–1.54, CI 77–81, SL 1.59–1.70, SI 110–120, FW 0.68–0.75, FI 49–52, WL 2.70–3.07, ScW 1.52–1.76, MnL 1.93–2.13, HTL 1.85–2.13.

With the usual differences from the worker caste.

Type Material

Rigato (2016) - Holotype gyne, CAMEROUN (L. Conradt) (Museo Civico di Storia Naturale, Genoa) [not seen].

References

References based on Global Ant Biodiversity Informatics

  • Rigato F. 2016. The ant genus Polyrhachis F. Smith in sub-Saharan Africa, with descriptions of ten new species. (Hymenoptera: Formicidae). Zootaxa 4088: 1-50.