Camponotus atimo, 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 atimo sp. nov.

Figs 24A , 26B , 30A , 43

Holotype worker.

Madagascar: Province Toliara: 3.5 km 236° SW Marovato, -25.55389, 45.25583, 230 m, spiny forest/thicket, ex rotten log, 14 Feb 2002 (Fisher, Griswold, and Arthropod Team) collection code: BLF05595, specimen code: CASENT0454042 ( CAS).

Paratype.

1 major worker same data as holotype but specimen coded as: CASENT0454043 (major) ( CAS).

Additional material examined.

Madagascar: Antsiranana: Nosy Be, RNI Lokobe, 6.3 km 112° ESE Hellville, -13.41933, 48.33117, 30 m, rainforest, (J.-J. Rafanomezantsoa et al.) ( CAS); RS Ankarana, 13.6 km 192° SSW Anivorano Nord, -12.86361, 49.22583, 210 m, tropical dry forest (Fisher, Griswold et al.) ( CAS); Sahamalaza Peninsula, Forêt d’Anabohazo, 21.6 km 247° WSW Maromandia, -14.30889, 47.91433, 120 m, tropical dry forest (Fisher, Griswold et al.) ( CAS). Fianarantsoa: Forêt d’Analalava, 29.6 km 280° W Ranohira, -22.59167, 45.12833, 700 m, Uapaca woodland (Fisher, Griswold et al.) ( CAS). Mahajanga: Melaky Region, District of Maintirano, Ampasy 50 km E of Maintirano, -18.004, 44.452, 85 m, dry forest (Mike, Rin’ha) ( CAS). Toliara: 3.4 km 190° S Marovato, -25.55972, 45.2825, 160 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); 3.5 km 236° SW Marovato, -25.55389, 45.25583, 230 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); 4.4 km 148° SSE Lavanono, -25.45056, 44.97417, 60 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); 7.0 km 156° SSE Lavanono, -25.47111, 44.9885, 50 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); Anosy Region, District of Amboasary, PN Andohahela, Parcelle III, Ihazofotsy, 32 km NE Amboasary, -24.83083, 46.53617, 58 m, dry forest, spiny forest (Michael Irwin, Frank Parker, Rin’ha) ( CAS); Anosy Region, District of Fort-Dauphin, PN Andohahela, Parcelle II, Tsimela, 42 km W of Fort-Dauphin, -24.93683, 46.62667, 176 m, transition forest (Michael Irwin, Frank Parker, Rin’ha) ( CAS); Anosy Region, PN Andohahela, Forêt de Manatalinjo, -24.82466, 46.60111, 100 m, spiny forest/thicket (B.L. Fisher, F.A. Esteves et al.) ( CAS); Atsimo Andrefana Region, District of Betioky ; RS Beza Mahafaly Parcelle Belle vue 07 km W of Research Station, -23.68983, 44.5755, 177 m, spiny forest, ( Rin’ha) ( CAS); Atsimo-Andrefana Region, -23.55275, 43.74471, 45 m, coastal scrub on limestone (B.L. Fisher, F.A. Esteves et al.) ( CAS); Atsimo-Andrefana Region, -23.53922, 43.77935, 20 m, riparian scrub (B.L. Fisher, F.A. Esteves et al.) ( CAS); Atsimo-Andrefana Region, Antsokay Arboretum, -23.41491, 43.75499, 13 m, spiny forest/thicket (B.L. Fisher, F.A. Esteves et al.) ( CAS); Forêt de Beroboka, 5.9 km 131° SE Ankidranoka, -22.23306, 43.36633, 80 m, tropical dry forest (Fisher-Griswold Arthropod Team) ( CAS); Forêt de Mahavelo, Isantoria River, -24.75833, 46.15717, 110 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); Forêt de Tsinjoriaky, 6.2 km 84° E Tsifota, -22.80222, 43.42067, 70 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); Mahafaly Plateau, 6.2 km 74° ENE Itampolo, -24.65361, 43.99667, 80 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); PN Andohahela, Forêt d’Ambohibory, 1.7 km 61° ENE Tsimelahy, 36.1 km 308° NW Tolagnaro, -24.93, 46.6455, 300 m, tropical dry forest (Fisher-Griswold Arthropod Team) ( CAS); PN Andohahela, Forêt de Manatalinjo, 33.6 km 63° ENE Amboasary, 7.6 km 99° E Hazofotsy, -24.81694, 46.61, 150 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); PN Tsimanampetsotsa, Forêt de Bemanateza, 20.7 km 81° E Efoetse, 23.0 km 131° SE Beheloka, -23.99222, 43.88067, 90 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); PN Tsimanampetsotsa, Mitoho Cave, 6.4 km 77° ENE Efoetse, 17.4 km 170° S Beheloka, -24.04722, 43.75317, 40 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); RS Cap Sainte Marie, 12.3 km 262° W Marovato, -25.58167, 45.16833, 200 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); RS Cap Sainte Marie, 14.9 km 261° W Marovato, -25.59444, 45.14683, 160 m, spiny forest/thicket (Fisher-Griswold Arthropod Team) ( CAS); 3 km E Itampolo, malaise across path of lower bench of Andrimpano Forest, -24.65783, 43.95617, 45 m, dry forest (M.E. Irwin, Rin’ha) ( CAS); 5 km E Itampolo, malaise across path of plateau of Andrimpano Forest, -24.65033, 43.96317, 130 m, dry forest (M.E. Irwin, Rin’ha) ( CAS); 5 km N Ampotaka, malaise on trail in Vitambany gallery forest, -24.65033, 43.96317, 86 m, Gallery forest (M.E. Irwin, Rin’ha) ( CAS); Ambohimahavelona village 33 km NE of Tulear, Andoharano dry forest, -23.44083, 43.89967, 46 m, dry forest (M.E. Irwin, Rin’ha) ( CAS); PN Andohahela, Ihazofotsy - Parcel III, transition forest, -24.83483, 46.48683, 80 m, transition between spiny and dry deciduous forests (M.E. Irwin, F.D. Parker, R. Harin’Hala) ( CAS); Mikea Forest, deciduous dry forest, -22.90367, 43.4755, 30 m, deciduous dry forest (R. Harin’Hala) ( CAS); Parcel I, RS Beza Mahafaly, near research station, -23.6865, 44.591, 165 m, dry deciduous forest (R. Harin’Hala) ( CAS); PN Tsimanampetsotsa, Mitoho Forest, malaise across trail at escarpment base, -24.0485, 43.75233, 120 m, dense dry forest (M.E. Irwin, Rin’ha) ( CAS); Tsimelahy - Parcel II, PN Andohahela, transition forest, -24.93683, 46.62667, 180 m, transition forest (M.E. Irwin, F.D. Parker, R. Harin’Hala) ( CAS).

Diagnosis.

With head in full-face view, lateral margins of head anterior to eye level parallel, lacking erect hairs; in oblique profile, four or more pairs of erect hairs arranged successively from level of anterior ocular margin towards posterior cephalic margin; clypeus with distinct anterolateral corner; in profile, junction of propodeal dorsum to declivity rounded; petiole nodelike and not anteroposteriorly compressed.

Description.

Minor worker. With head in full-face view, lateral margins anterior to eye level parallel, converging abruptly towards posterior margin behind eye level; eye large and convex (EL/CS: 0.28 ± 0.01; 0.26-0.30), interrupting lateral cephalic border, level of its posterior margin situated approximately at posterior 1/3 of head (PoOc/CL; 0.27 ± 0.01; 0.25-0.29); frontal carinae close to each other, their distance equal to or smaller than their smallest distance to eye (FR/CS: 0.23 ± 0.01; 0.22-0.25); clypeus with anterolateral angle and broadly convex anteromedian margin; mandible with two apical teeth distant from each other; antennal scape relatively long (SL/CS: 1.66 ± 0.09; 1.48-1.84). Promesonotum weakly convex and mesopropodeum feebly convex (MPH/ML: 0.33 ± 0.02; 0.29-0.36), mesonotum flat near weakly visible metanotal groove; propodeal dorsum anteriorly convex, posteriorly flat, rounding to declivity; propodeal dorsum 2 × as long as declivity. Petiole nodiform, its dorsal margin inclined posteriorly, rounding to anterior margin; anterior face 1/2 height of posterior face; femur of hind leg rounded axially, not twisted near base.

First and second gastral tergites without a pair of white spots; lateral margin of head without erect hairs; posterior cephalic margin with a pair of erect hairs; in profile, four pairs of erect hairs arranged from level of anterior margin of eye to posterior cephalic margin; erect hairs lacking from antennal scape, pubescence present; pronotum with a pair of erect hairs; posterodorsal angle of propodeum without erect hairs.

Major worker. With characteristics of minor worker, except for the typically broader head (CS: 3.23 ± 0.34; 2.80-3.77; CWb/CL: 0.97 ± 0.04; 0.89-1.03), with broadly concave posterior margin; apical 1/3 of antennal scape extending beyond posterior cephalic margin; robust mesosoma, with propodeal dorsum convex immediately posterior to metanotal groove and < 2 × as long as declivity; petiolar node compressed anteroposteriorly.

Distribution and biology.

Camponotus atimo , endemic to Madagascar, generally occurs in the southern part of the island (Fig. 43D ). Its habitats range from dry forest and coastal scrub on limestone of the southwestern region to the transitional forest in the extreme southeastern region and Uapaca woodland in the south-central region through the spiny forest and thicket in the extreme south of the island. Field work during the past 25 years has found this species foraging mostly on the ground and through leaf litter, and very rarely on lower vegetation. It usually nests under stones, in rotten logs and soil layers, and rarely in tree stumps.

Discussion.

Camponotus atimo may be difficult to distinguish from C. tapia in that both species have the same body shape and the dorsum of the head is fringed with four or more pairs of erect hairs arranged successively from the level of the anterior ocular margin towards the posterior cephalic margin. However, in C. tapia , the junction of the propodeal dorsum to declivity surface is angulate.

Camponotus atimo also may be confounded with C. strangulatus , but the latter is characterized by the head having only three pairs of erect hairs arranged successively from the level of anterior ocular margin towards the posterior cephalic margin.

The identity of C. atimo , based on traditional qualitative taxonomy, has been confirmed by multivariate morphometrics. The grouping of the samples of C. atimo generated by the NC-clustering method is corroborated by cumulative LDA with a classification success of 100%.

Etymology.

This new name atimo is a singular non-Latin noun used in apposition, derived from the Malagasy word for “south” in reference to the restricted distribution of the species to the southern half of Madagascar.

Figures

Figure 24. Head in full-face view A C. atimo (CASENT 0454042) B C. quadrimaculatus (CASENT 0096044).

Figure 26. Posterior portion of mesosoma, petiolar node, and gaster in lateral view A C. bozaka (CASENT 0217309) B C. atimo (CASENT 0454042).

Figure 30. Mesosoma in lateral view A C. atimo (CASENT 0454042) B C. tapia (CASENT 0217310).

Figure 43. Camponotus atimo A lateral view B head in full-face view C dorsal view of holotype minor worker CASENT 0454042 D distribution map.