Axinidris acholli

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Axinidris acholli
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dolichoderinae
Genus: Axinidris
Species: A. acholli
Binomial name
Axinidris acholli
Weber, 1941

Axinidris acholli casent0217121 p 1 high.jpg

Axinidris acholli casent0217121 d 1 high.jpg

Specimen Labels

Specimens have been taken from vegetation above ground level (Weber 1941) and "I have collected numerous workers from KENYA, Kakamega District, Isecheno, Kakamega Forest (00.24°N 034.85°E), 1550-1600m (LACM), running on vines, except two in litter. All specimens were in dense forest as opposed to being on trees at the edge of a clearing." (Snelling 2007)

Identification

Snelling (2007) - Pronotal disc with 8-10 coarse rugae that more or less diverge behind; mesepisternum with 4 or 5 coarse longitudinal to oblique rugae; medial propodeal carina compressed and conspicuously higher than long and longer dorsally than at base; head and body with abundant long, slender whitish hairs.

The bizarrely developed propodeal structures are sufficient to separate A. acholli from all the known remaining species. Additionally, no other species is known that has such an abundance of long, flexuous white hairs. Only Axinidris lignicola and Axinidris stageri are almost as hairy, but in both the propodeal structures are much less extreme, the hairs are shorter and straighter, and the antennal scapes are proportionately much shorter.

Keys including this Species

Distribution

Snelling (2007) - In addition to Sudan and Kenya, I expect that A. acholli will also be found in Uganda and the Democratic Republic of Congo, at the very least.

Distribution based on Regional Taxon Lists

Afrotropical Region: Kenya, Sudan (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Species of Axinidris appear to nest exclusively within hollow plant stems, both living and dead, and in rotten wood. They are found in forested areas throughout the Afrotropical region, but are most abundant and diverse in the moist equatorial forests. Workers are primarily arboreal foragers, but may occasionally forage in ground litter.

Castes

Known only from the worker caste.

Nomenclature

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

  • acholli. Axinidris acholli Weber, 1941a: 193, figs. 10-12 (w.) SUDAN. See also: Shattuck, 1991: 109; Snelling, R.R. 2007: 556.

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

Snelling (2007) - I had originally regarded the Kenyan specimens as a previously undescribed species. When I examined the two type specimens of A. acholli, however, I began to doubt that this was correct. The only difference that I could discern was that the Kenyan specimens were abundantly hairy while the A. acholli types were almost completely devoid of hairs. The type specimens, lectotype and lectoparatype, consist of fragments mounted on points. The lectotype head has only a single antenna. The lectoparatype is in even worse condition: the head lacks antennae, the mesosoma is partly broken, and only a single detached hind leg is present. Both specimens appear to be severely abraded, lacking hairs where all other species possess hairs (e.g., the mandibles, clypeus, frontal carinae). Once it was clear that these poor specimens had been artificially denuded, it was obvious that my fresh Kenyan samples were conspecific.

Description

Worker

Shattuck (1991) - (n=2). OOD 0.36-0.39, EL 0.22-0.23, HL 0.96, EW 0.11-0.12, HW 0.86-0.88, CNW 0.05-0.07, CND 0.06, SL 0.84, AL 1.16-1.19, PpW 0.36-0.38, SW 0.32-0.36, CI 0.90-0.92, CNI 0.84-1.10, REL 0.25-0.27, ScI 0.96, SpI 1.46-1.64.

Posterior pronotum and mesonotum anterior of spiracles with c. 7 to c. 10 large, distinct rugae; medial propodeal carina expanded dorsally, taller than long and with the attachment narrower than the dorsal extremity.

Head scabriculous with the interrugal spaces punctate, punctations stronger and scabriculations weaker laterally; the area near the mandibular insertion with a narrow area of strigulate sculpturing. Pilosity limited to one pair of short erect hairs on the frontal lobes. Erect or suberect hairs absent from the antennal scapes. The anterior regions of pronotum punc¬tate, posterior dorsal regions and entire meso¬notum smooth and with numerous longitudinal rugae; lateral edges of pronotum strongly mar¬gined. Dorsal pronotal surface lacking erect hairs. Propodeum smooth with small, widely spaced punctures. Propodeal spiracle raised anteriorly and posteriorly above the surround¬ing propodeum and connected anteriorly by a ridge to the underlying propodeum. Medial propodeal carina expanded dorsally into an axe head-like shape, with the attachment beginning just anterior of a line drawn between the spiracles and ending even with a line drawn between the propodeal spines. Propodeal spines elongate, curved postero-Iaterally, with the outer surfaces concave, the distal ends about the same width as the maximum propodeal width, and the area between them flat or slightly convex. Erect hairs present on gastric tergites 3 and 4. Body colour reddish brown, with the mandibles and antennae lighter, and the tarsi reddish yellow.

Type Material

Shattuck (1991) - Two worker syntypes from SUDAN: Imatong (=Matong) Mountains, 6200 and 4800 ft (N. A. Weber) (Museum of Comparative Zoology) [examined]. The specimen from 6200 ft is here designated as LECTOTYPE.

References