Aenictus congolensis

Aenictus congolensis
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Dorylinae
Genus:	Aenictus
Species group:	rotundatus
Species complex:	rotundatus
Species:	A. congolensis
Binomial name
	Aenictus congolensis; Santschi, 1911 Specimen Labels

Specimen records show this species has been collected from sifted litter in rainforest, leaf mold and rotten wood, and Miombo woodland soil.

Identification

Gómez (2022) - A member of the rotundatus species complex in the Aenictus rotundatus species group. Identification of A. congolensis is quite straightforward in the rotundatus group due to its developed propodeal ridge and sparse, adpressed white setae and long, digitiform subpetiolar process. The other two species with developed propodeal ridge (Aenictus nyuyi and Aenictus weissi) present erect to suberect setae and poorly developed subpetiolar process.

Mesosomal sculpture may be quite variable among individuals, varying from completely and deeply reticulated to individuals with glassy dorsal mesosoma, petiole and postpetiole.

Keys including this Species

Key to the Afrotropical Aenictus

Distribution

Identification

Keys including this Species

Key to the Afrotropical Aenictus

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 6.216666667° to -12°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps; Gomez, 2022

Distribution based on Regional Taxon Lists

Afrotropical Region: Central African Republic, Congo (type locality), Gabon, Zambia.

Distribution based on AntMaps

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.

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.

Biology

Castes

Known from the worker and queen castes. Table of castes known for all Afrotropical Aenictus species.

Worker

Images from AntWeb


Worker. Specimen code casent0066799. Photographer Michele Esposito, uploaded by California Academy of Sciences.	Owned by CAS, San Francisco, CA, USA.

Images from AntWeb


Syntype of Aenictus rixator congolensis. Worker. Specimen code casent0911445. Photographer Z. Lieberman, uploaded by California Academy of Sciences.	Owned by NHMB, Basel, Switzerland.

Queen

Wheeler 1930. Figure 2. a) female, dorsal view; b) same in profile; c) hypopygium of same; d) head of worker, dorsal view; e) worker, dorsal view, drawn to the same scale as a) and b); f) worker more enlarged in profile; g) pedicel of same in profile; h) antenna of same; i) mandible of same; j) same of another worker specimen; k) mandible seen from above.

Images from AntWeb


Syntype of Aenictus congolensis. Queen (alate/dealate). Specimen code casent0911419. Photographer Z. Lieberman, uploaded by California Academy of Sciences.	Owned by NHMB, Basel, Switzerland.

Nomenclature

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

congolensis. Aenictus rixator var. congolensis Santschi, 1911g: 207 (w.) CONGO.
- Type-material: holotype worker.
- [Note: original description gives no indication of number of specimens, but Santschi, 1917a: 277, says the taxon was originally based on a single worker, confirmed by Baroni Urbani, 1977e: 67.]
- Type-locality: Congo (“Congo français”): (no further data) (A. Weiss).
- [Notes (i): Gómez, 2022: 60, includes a specimen from Cameroon as a syntype, a locality not mentioned in the original description; (ii) he also includes as syntypes the specimens redescribed by Santschi, 1917a: 277, which are not type-material.]
- Type-depository: NHMB.
- Santschi, 1917a: 277 (q.).
- Status as species: Santschi, 1917a: 277 (redescription); Wheeler, W.M. 1922a: 751; Bolton, 1995b: 59; Gómez, 2022: 60 (redescription).
- Distribution: Cameroon, Central African Republic, Congo, Gabon, Zambia.

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

Description

Worker

Worker (Translated from the original): Length 2mm. Thorax, posterior half of the head and petiole dark reddish brown, the rest borwnish yellow. Head, postpetiole and gaster smooth and shiny. Thorax and petiole matt, reticulated, punctuated (like a thimble) over almost the whole propodeum. Mandibles very finely reticulated and finely striated. Pilosiy short, decumbent, yellowish, all over body and legs. Mandibles with 3 to 6 teeth, the apical longer than in ceylonicus. Funicular segments 3 to 7 wider than long. The rest like the type.

Gómez (2022) - HL: 0.57 [0.51-0.62]; HW: 0.51 [0.46-0.56]; SL: 0.40 [0.35-0.43]; WL: 0.91 [0.79-1.01]; PL: 0.22 [0.19-0.25]; PH: 0.16 [0.15-0.18]; PPL: 0.18 [0.16- 0.20]; PPH: 0.13 [0.12-0.14]; CS: 0.54 [0.48-0.59]; CI: 89 [85-94]; SIL: 70 [67-74]; SIW: 78 [72-85]; WL/HW: 178 [164-191]; PI: 134 [126-143]; PPI: 135 [123-153]; CSR: 122; (n=11).

Scapes relatively long, almost reaching three quarters of head (SIL~70). Funicular segments 1- 2 slightly longer than wide, 3–8 subquadrate, apical about twice longer than wide. Head rectangular, longer than wide (CI~90), convex laterally and widest at the middle. Occipital line straight to slightly concave. Ventrolateral margin present, weak, continuing to one third of its length. Mandibles long, with a sharp apical tooth, a preapical tooth and 5-10 smaller denticles. Clypeus a row of 10–12 conical teeth, clearly visible and longer than wide, the two central between the antennal sockets smaller. Frontal ridges present, not projecting frontally, fused between the antennal sockets and diverging apically.

Pronotum and mesonotum weakly convex, propodeum flat, mesopropodeal suture weak. Transverse mesopleural groove not present. Mesometapleural suture present but very weak; propodeal ridge developed and projecting as a horizontal shelf in dorsal view; propodeal declivity concave.

Petiole subsessile with anterolateral and anterodorsal ridges present, dorsolateral ridge absent. Petiole with an anterior slope a quarter of ellipse, dorsal slope flat and vertical posteriorly, posterodorsal angle straight, not rounded. Postpetiole rounded, with a vertical posterior face, without carinae or ridges of any kind. Subpetiolar process developed with a bulky ellipsoidal process longer than high, followed by a subrectangular rounded lamella oriented 45 degrees forward.

Head, legs and gaster glassy smooth; mandibles finely horizontally rugulose, scapes and funiculus punctuated, shagreened; mesosoma variable, from completely reticulated (including pronotum) to individuals with pronotum, dorsum of mesonotum, petiole and postpetiole smooth; mesopleurae, propodeum and lateral sides of petiole and postpetiole always reticulated. Overall colour brown to dark brown, sometimes slightly lighter at gaster and legs. Short, adpressed white setae, oriented backwards, present at head, dorsum of pronotum petiole, postpetiole and gaster. No pubescence noted.

Type Material

Syntype, GABON: Mayomba. (1w) [CASENT0911420] NHMB [Examined by Gomez, 2022]; Syntype, CAMEROON, Grand Batanga (1w) [CASENT0911445] NHMB [Examined by Gomez, 2022].

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.
IZIKO South Africa Museum Collection
Santschi F. 1917. Description d'une nouvelle reine de Formicide du genre Aenictus Shuckard. Annales de la Société Entomologique de France 85: 277-278.