Camponotus niavo, Rakotonirina & Fisher, 2022

Rakotonirina, Jean Claude & Fisher, Brian L., 2022, Revision of the Malagasy Camponotus subgenus Myrmosaga (Hymenoptera, Formicidae) using qualitative and quantitative morphology, ZooKeys 1098, pp. 1-180 : 1

Camponotus niavo sp. nov.

Figs 10A , 68

Holotype worker.

Madagascar: Province Antsiranana: PN Montagne d’Ambre, Antomboka, -12.50035, 49.175, 885 m, montane rainforest, ex rotten log, 16 Nov 2007 (B.L. Fisher et al.) collection code: BLF18356 specimen code: CASENT0134004 ( CAS).

Paratype.

1 major worker of same data as holotype but with specimen code: CASENT0134003 ( CAS).

Additional material examined.

Madagascar: Antsiranana: Ampasindava, Foret d'Ambilanivy , 3.9 km 181° S Ambaliha, -13.79861, 48.16167, 600 m, rainforest (Fisher, Griswold et al.) ( CAS); Galoko chain, Mont Galoko, -13.58487, 48.71818, 520 m, rainforest (B.L. Fisher et al.) ( CAS); Galoko chain, Mont Kalabenono, -13.64609, 48.67732, 937 m, rainforest (B.L. Fisher et al.) ( CAS); PN Montagne d’Ambre, Antomboka, -12.50035, 49.175, 885 m, montane rainforest (B.L. Fisher et al.) ( CAS); RS Manongarivo, 10.8 km 229° SW Antanambao, -13.96167, 48.43333, 400 m, rainforest (B.L. Fisher) ( CAS); RS Manongarivo, 12.8 km 228° SW Antanambao, -13.97667, 48.42333, 780 m, rainforest (B.L. Fisher) ( CAS) .

Diagnosis.

With head in full-face view, lateral cephalic margin converging posteriorly towards eye level, covered with erect hairs anterior and posterior to eye level; anteromedian margin of clypeus broadly convex; two apical teeth of mandible normally spaced.

Description.

Minor worker. In full-face view, head widest at midlength, lateral margins posterior to level of eye rounding evenly to posterior margin; eye large, slightly convex (EL/CS: 0.27 ± 0.01; 0.26-0.30), not breaking lateral cephalic margin, level of its posterior margin located approximately at posterior 1/4 of the head (PoOc/CL: 0.28 ± 0.02; 0.25-0.32); frontal carinae wide (FR/CS: 0.25 ± 0.01; 0.24-0.28), distance between them larger than their distance to eye; clypeus with anterolateral angle and anteromedian margin with blunt or convex angle; mandible with two apical teeth distantly spaced; antennal scape relatively long (SL/CS: 1.70 ± 0.11; 1.59-1.88). Promesonotum weakly convex, posterior portion of mesonotum flat immediately anterior to weakly visible metanotal groove; propodeal dorsum almost straight; dorsal margin of propodeum and declivity junction bluntly rounded; propodeal dorsum 2 × as long as declivity. Petiolar node short and high, its dorsal margin inclined posteriorly and joining anterior face in a blunt angle; anterior face 1/3 of height of the posterior; femur of hind leg rounded axially, without torsion near base.

First and second gastral tergites without a pair of white spots; erect hairs present on lateral margin of head, near its posterior margin bearing more than six erect hairs; antennal scape with suberect hairs inclined at ca. 30°, appressed hairs lacking; promesonotum covered with erect hairs; posterodorsal angle of propodeum with more than two erect hairs.

Major worker. Differing from minor worker in the following characters: enlarged head (CS: 4.02 ± 0.35; 3.69-4.61; CWb/CL: 0.92 ± 0.08; 0.79-1.01); more robust mandible; apical 1/4 of antennal scape surpassing posterior cephalic margin; pronotum convex, mesonotum sloping towards metanotum, propodeal dorsum feebly convex and joining the declivity at a broad angle; petiolar node higher than long.

Distribution and biology.

Camponotus niavo is geographically restricted to the transitional humid forest of Ampasindava Peninsula, the rainforests of the Galoko chain and RS Manongarivo, and the montane rainforest of the PN Montagne d’Ambre (Fig. 68D ). Colony nests are established in rotten logs and rotting tree stumps, while foraging is carried out on the forest floor and through leaf litter.

Discussion.

See discussion under C. cervicalis .

The qualitative, morphology-based analysis of this species agrees with the multivariate morphometric analysis to provide 100% support for the taxonomic determination of C. niavo .

Etymology.

The species name niavo is a non-Latin singular noun used in apposition and is derived from the Malagasy word that means "from above". It refers to the high mountains where the species has been collected.

Figures

Figure 10. Head in full-face view A C. niavo (CASENT 0134004) B C. cervicalis (CASENT 0217303).

Figure 68. Camponotus niavo A lateral view B head in full-face view C dorsal view of holotype minor worker CASENT 0134004 D distribution map.