Aenictus jacki, Gómez, 2022

Gómez, Kiko, 2022, A revision of the Afrotropical species of the Dorylinae ant genus Aenictus (Hymenoptera: Formicidae) based on the worker caste, Belgian Journal of Entomology 124, pp. 1-86 : 68-70

Aenictus jacki sp. nov.

Zoobank: 0D38F4F1-D5EA-4FAB-A063-8F0631928270

( Figs 52 A–D , 53 )

Holotype worker: MOZAMBIQUE: • Sofala, 3 km SE Chitengo , Gorongosa Nat. Park 40 m, - 19.00352, 34.37811; search (J. Longino); riparian moist forest (1w), in soil [ JTL761548A02 ] BMNH.

Paratype workers: • same series (1w) [ CASENT0840034 ] FHGC; (1w) [ CASENT0840036 ] CASC; (1w) [ CASENT0840037 ] MHNG; (1w) [ CASENT0840038 ] RBINS; (1w) [ CASENT0840039 ] KGPC; (1w) [ CASENT0840040 ] AFRC; (1w) [ CASENT0840041 ] BMNH; (1w) [ CASENT0840042 ] JTLC; (1w) [ CASENT0840042 ] SAMC; (7w in ethanol) [ JTL761548 ] JTLC .

DIAGNOSIS. Identification of A. jacki sp. nov. is quite straightforward in the rotundatus group due to its abundant reclined white setae. Only A. congolensis presents adpressed setae, but they are separable due to the much shorter scapes (SIL<61 for A. jacki sp. nov., SIL>68 for A. congolensis), the much sparser pilosity, more developed propodeal ridge and digitiform shape of subpetiolar process in A. congolensis.

DESCRIPTION ( Fig. 52 A–D ). WORKER HL: 0.57 [0.52-0.62]; HW: 0.49 [0.46-0.52]; SL: 0.34 [0.30-0.36]; WL: 0.84 [0.78-0.89]; PL: 0.21 [0.20-0.22]; PH: 0.14 [0.13-0.15]; PPL: 0.15 [0.14- 0.16]; PPH: 0.13 [0.11-0.14]; CS: 0.53 [0.49-0.57]; CI: 85 [83-88]; SIL: 59 [57-60]; SIW: 69 [66-72]; WL/HW: 171 [165-175]; PI: 144 [133-153]; PPI: 120 [107-136]; CSR: 116; (n=8).

With the characteristics of the rotundatus species complex and: scapes short, just passing the median line of the head when laid back (SL/HL~0.62). Funicular segments subquadrate, apical more than twice longer than wide. Head rectangular, longer than wide (CI~86), slightly widest at the middle. Occipital line slightly concave. Mandibles triangular with a long, sharp apical tooth, one small preapical tooth and 4–5 smaller denticles. Clypeus very reduced, with a row of very small, triangular teeth, which can be very eroded and difficult to discern when mandibles closed. Frontal ridges present, fused between the antennal sockets.

Pronotum slightly convex, with the mesopropodeal suture very weak, concave, meeting the flat propodeum at an angle. This with a very reduced but discernible anterior slope and elevated over the mesonotum. Transverse mesopleural groove present and discernible as a darker line at its first anterior half. Mesometapleural suture present but weak. Propodeal declivity vertical and flat; propodeal ridge absent.

Petiole sessile with anterolateral ridges present, anterodorsal and dorsolateral ridges absent. Petiolar node rounded, anteriorly a quarter of ellipse, small flat dorsal surface and almost vertical posteriorly; postpetiolar dome quadrate in lateral view with vertical anterior and posterior faces, the first one shorter, and horizontal dorsally, with rounded angles; subpetiolar process strongly developed, with a small elliptical process followed by a big triangular lamellae oriented downwards, the lamella as big or usually larger than the rest of the process.

Mandibles smooth to patchly shagreened, sometimes with irregular small rugulae; head, scapes, pronotum, mesonotum, dorsopostpetiole, legs and gaster glassy smooth; mesopleurae and propodeum strongly reticulate, matt, with some short horizontal and incomplete rugulae laterally; petiole and lateroposteptiole alutaceus to reticulated. Overall colour light brown, punctate zones and sutures darker.

Sides of head and mandibles with semierect to erect setae; rest of the head, except vertex, with decumbent to adpressed setae oriented outwards; vertex and surroundings to the occiput with slightly longer decumbent to semierect setae, oriented to the midline, creating a small dome; scapes with unequal decumbent to semierect setae, the longest longer than scape width; dorsal surfaces of pronotum, metanotum, petiole and postpetiole as well as the whole gaster densely covered with very abundant, semierect to reclinate setae, similar in length and shorter than propodeum height; most of the setae bent to the horizontal and pointing backwards; dorsopropodeum bare, posteropropodeum with scattered erect setae. Legs covered with semierect setae, shorter than maximum tibiae width; all setae white. No pubescence noted.

DERIVATIO NOMINIS. The species name jacki is Latinized noun in the genitive case, dedicated to Dr. John Longino, who kindly sent me the material.

OTHER MATERIAL EXAMINED. Known only from the type series.

DISTRIBUTION. Eastern African, known from Mozambique ( Fig. 53 ).

Figures

Fig. 52. Aenictus jacki sp. nov., paratype (CASENT0840036). A, head, dorsal view. B, habitus, lateral view. C, mesosoma, petiole and postpetiole, lateral view. D, mesosoma, petiole and postpetiole, dorsal view.

Fig. 53. Distribution of A. jacki sp. nov.