﻿A taxonomic revision of the Malagasy endemic subgenus Mayria of the genus Camponotus (Hymenoptera, Formicidae) based on qualitative morphology and quantitative morphometric analyses

﻿Abstract The subgenus Mayria of the genus Camponotus (Hymenoptera: Formicidae) is revised. The subgenus is endemic to Madagascar where it occupies a broad range of habitats, from deciduous and dry forest to rainforest. A taxonomic review is provided of this subgenus, integrating multiples lines of evidence including qualitative morphology and quantitative morphometry. Species hypotheses are formed by Nest Centroid clustering. In total, 36 species are treated, of which eleven are newly described: Camponotusandrianjakasp. nov., Camponotusantsaraingysp. nov., Camponotuschrislainisp. nov., Camponotusclaverisp. nov., Camponotusivadiasp. nov., Camponotusjjacquiasp. nov., Camponotusmaintilanysp. nov., Camponotusnorvigisp. nov., Camponotusihazofotsysp. nov., Camponotustsimelahysp. nov., Camponotuszorosp. nov. Five species are redescribed. Camponotusthemistocles Forel stat. nov., is raised to species. In addition, the subgenus is redefined to include 39 species. Twenty-two previously described species are transferred to this subgenus and thirteen species previously placed in the subgenus are transferred out of the subgenus. Nine morphologically consistent species groups are delineated to facilitate species identification within the subgenus. This revision includes a classification, a key to species groups, and an updated key to species based on the minor worker caste.


Introduction
The genus Camponotus Mayr, 1861 is one of the most speciose and widespread genera within the Formicidae, comprising more than 90 described species and subspecies in the Malagasy region. This genus has received renewed attention over the last five years. In 2016, the Camponotus edmondi species group was revised by Rakotonirina et al. (2016). Later, Camponotus grandidieri and niveosetosus species groups, the subgenera Myrmopytia and Mayria have been revised (Rakotonirina et al. 2017;Rasoamanana et al. 2017;Rakotonirina and Fisher 2018). In total, 41 species were included in these studies, which combined qualitative morphological analysis, multivariate morphometry, and ecological data. Here we continue to explore the taxonomy of Malagasy Camponotus and revisit the subgenus Mayria. We redefine the subgenus and describe additional species using morphological features combined with morphometry.
In the 2018 revision by Rakotonirina et al.,14 species were recognized in the subgenus. However, our further studies of Malagasy Camponotus species have revealed additional morphological traits leading to new groupings. This revision increases the size of subgenus Mayria with the transfer of 15 species from the edmondi species group (Rakotonirina et al. 2016) and six species from niveosetosus species group (Rakotonirina et al. 2017), and the description of eleven new species and the redescription of six previously described species. Together, these changes increase the total number of species in this subgenus to 39. We divide this subgenus into nine species groups: alamaina group, antsaraingy group, darwinii group, edmondi group, efitra group, ellioti group, madagascarensis group, repens group, and robustus group.

Materials and methods
This study is based on specimens collected from the ant inventory of Madagascar project as part of a joint collaboration between CAS and Parc Botanique et Zoologique Tsimbazaza under the aegis of the Ministry of Higher Education in Madagascar. After morphological examination, all workers were separated into morphospecies, and measurements of the 19 characters were recorded for specimens in good condition. The data were subjected to a multivariate analysis, which utilized the Nest Centroid (NC)-Clustering method to determine whether differences existed among workers within the same species. The degree of inclination of pilosity is particularly important for diagnosing groups or species. In this context, we use the terms erect, suberect, subdecumbent, decumbent, and appressed following Wilson (1955).
PoOC Postocular distance. The longest distance between the posteromedian margin of the head and theposterior margins of the two compound eyes. Measured at a right angle to the reference line in full-face view (Fig. 1A). PrAC Preocular distance. The longest distance between the anteromedian margin of the clypeus and the level of the anterior margin of the compound eyes as a reference line. Measured at a right angle to the reference line in full-face view (Fig. 1A).

SL
Scape length. Straight line length of the first antennal segment excluding the basal condyle (Fig. 1B). TCD Torular carina distance. The minimum distance between the torular arches that surround the antennal insertion (Fig. 1A).
Mesosoma in lateral view, dorsal outline of mesosoma continuous (darwinii group) to complex (other groups). Promesonotal suture visible. Pronotum: humeral angle tuberculate (C. ellioti species group), marginate in the remaining species group; in dorsal view, pronotal disc usually rectangular. Mesonotum in dorsal view, wider than long; laterally marginate in C. edmondi species group. Mesopleuron and propodeal surface together distinctly longer than lateral portion of pronotum in lateral view. Propodeal lobe reduced. Metapleural gland absent. Procoxa of normal to moderate size for C. edmondi species group. Middle and hind tibiae with single pectinate spur.
Petiolar node: broad and massive, ranging from squamiform to nodiform, posterodorsal edge of petiole always marginate and ornamented with thick, erect hairs.
Integument opaque and sculptured, ranging from finely and densely reticulatepunctate to finely and densely imbricate.
Pilosity: standing setae thick at least at the base, whitish to pale colored, erect to appressed hairs, filiform to spatulate hairs, moderately distributed on entire dorsum of head and body; ground pilosity always present and conspicuous.
Diagnosis of major worker. Most of the morphological traits cited above for minor workers are also characteristics of major workers. However, major workers exhibit the following characters: head more subquadrate to rectangular; malar area thimblelike with weak impression at the base of each seta ( Fig. 2K-M); lateral portion of head sculptured as finely and densely reticulate-punctate, imbricate, or areolate, and superimposed with two to seven smaller areoles embedded in scattered large punctures, from which an appressed hair arises medially; antennal scape shorter, its apex barely surpassing or not extending beyond posterior cephalic margin; dorsal outline of mesosoma with the same structure as minor worker.
Note. The type species Camponotus echinoploides of the subgenus Myrmepinotus shares the characters of the Mayria diagnosis and therefore Myrmepinotus is synonymized with Mayria. The following characters place C. echinoploides within the Mayria subgenus: in dorsal view, mesosoma relatively short and distinctly marginate anteriorly and laterally; pronotum and mesonotum widened; promesonotal and metanotal sutures well marked; in profile, petiolar node thick with convex anterior and posterior margins, and body covered with whitish, thick hairs. In fact, the lectotype of C. repens and the holotype of C. echinoploides share a suite of morphological characters: in fullface view, head elongate, broadened posteriorly with slightly convex sides; clypeus with short median lobe; in profile, anterior margin of pronotum strongly convex; pronotal disc subrectangular, marginate laterally; petiolar node as high as long; standing setae consist of thick, whitish hairs; body integument dull. These morphological characters are observed also in specimens belonging to the edmondi species group but absent for species that are removed from the subgenus Mayria (Table 2). Accordingly, we have treated Myrmepinotus as a synonym of Mayria.

Definition of the Camponotus alamaina species group
Minor worker: in full-face view, head subovate, distinctly longer than broad, lateral margin more or less straight and rounding to the broadly convex posterior margin (Fig. 3A). Anteromedian margin of clypeus generally convex; posteromedian margin slightly notched. Major worker: in full-face view, head subquadrate, posterior margin approximately straight and rounding to lateral margins. Clypeus hexagonal, its anterior border straight and medially excised, frontal triangle distinct (Fig. 3C).
Minor and major workers: Mesosomal profile almost flattened and interrupted by the impressed metanotal suture. Promesonotal dorsum flattened; anterodorsal angle of pronotum and dorsolateral portion of mesosoma bluntly marginate; posterolateral margin of propodeum rounding to declivitous surface ( Fig. 3B-D). In dorsal view, mesonotum as long as broad, but sides converging posteriorly; mesonotum and propodeum laterally compressed at their junction; metanotal groove vestigial, represented by a transverse line. In profile, petiolar node anteroposteriorly flattened and tapered dorsally; anterior margin slightly convex and posterior margin more or less straight; dorsal margin straight or weakly excised medially (Fig. 3D). Dorsum of head, mesosoma, and petiole with imbricate sculpture; gaster with finer imbrication; mandible coriariouspuncticulate. Pairs of erect hairs transversely arranged on mesosomal dorsum and in a row on gastral tergite, pubescence short and scattered on dorsum of body.
Remarks. The group is distinguishable from all other members of the subgenus Mayria by the combination of the following characters: mesosoma distinctly marked with promesonotal and metanotal sutures; petiole with sharp edge, its anterior margin convex and its posterior margin more or less straight; propodeal spiracle placed anterior to posterolateral margin of propodeum; head and mesosoma black to dark brown, gaster and appendages dark brown to yellow or depigmented yellow; cervical shield joining pronotal dorsum directly; junction of dorsal face to lateral face of propodeum without sharp carina, posterolateral margin present.
Even though Rakotonirina et al. (2016) described these three species as members of C. edmondi species group, these character states justify a different grouping. In addition, species of this group prefer arid habitats such as dry forest, spiny bush and thicket, and gallery forest, with the exception of Camponotus bevohitra, which can be found in montane rainforest.

Definition of the Camponotus antsaraingy species group
Minor worker: in full-face view, head subtriangular, longer than wide, with arched posterior margin and straight lateral sides. Clypeus with projecting triangular lobe (Fig. 4A).
Major worker: in full-face view, head large, about as broad as long, with slightly convex posterior and lateral borders. Anterior margin of clypeus forming a rounded lobe (Fig. 4C).
Minor and major workers: antennal scape entirely flattened longitudinally. In lateral view, mesosoma short and high, propodeal dorsum relatively shorter than declivi-tous face. Suberect spatulate hairs present on occipital portion until anterior margin of eyes and on clypeal dorsum, pubescence long and distinct, moderately abundant next to antennal insertion. Body massive, black throughout. In lateral view, petiole cuneiform, with sharp dorsal margin. Body integument matte black, finely and densely reticulate-punctate. Dorsum of mesosoma and gaster covered with numerous spatulate, whitish hairs (Fig. 4B, D).
Remarks. Camponotus antsaraingy is placed in its own group, based mainly on the following characters: its large size, the shape of its antennal scape, propodeum distinctly reduced, its dorsum covered with erect spatulate setae, and having only three gastral tergites visible in dorsal view. It is one of the groups in the subgenus Mayria with white pilosity. It differs from the madagascarensis species group by the structure of its mesosoma and its larger size.

Definition of the Camponotus darwinii species group
Minor worker: in full-face view, head more or less rectangular, with convex lateral sides and evenly straight occipital margin. Setae on dorsum of head sparsely distributed on occipital portion, arranged in longitudinal row along frontal carina (Fig. 5A). Major worker: in full-face view, head somewhat longer than broad, a little narrower in front than broad (Fig. 5C).
Minor and major worker: clypeus with short, truncated, or rounded rectangular median lobe, its dorsum covered with randomly spaced setae. Mesosomal profile continuous, promesonotal and metanotal suture not impressed, sometimes forming a shiny line. Petiole scale usually not thick, but thin or sharp along margins. Integument opaque, matte black or brown, distinctly reticulate-punctate throughout. Body mostly covered with coarse yellow, red, or white setae, sometimes forming a dense fur coating the gaster or mesosoma (Fig. 5B, D).
Remarks. Camponotus darwinii species group has consistently been considered a distinctive group because of the presence of coarser and denser pubescence on its dorsal margin; integument dull and sculptured; dorsal outline of mesosoma continuous. This group is distinguishable from all other members of the subgenus Mayria by the presence of dense, whitish pilosity on its dorsum and the arcuate profile of its mesosoma. Species in this group are traditionally classified under subgenus Myrmopiromis, type species Camponotus fulvopilosus, type location South Africa. The subgeneric definition by  and the revised definition of Camponotus fulvopilosus species group by Robertson (1990Robertson ( , 1997 are quite different from Camponotus darwinii species group. In addition to the species distribution, the number of mandibular teeth is a good character for distinguishing these two species groups: six for C. darwinii group and seven or eight for C. fulvopilosus group.

Definition of the Camponotus edmondi species group
Minor worker: in full-face view, head as long as broad, posterior margin broadly convex, lateral margins roughly straight (Fig. 6A).
Major worker: in full-face view, head subquadrate, posterior and lateral margins more or less straight to convex (Fig. 6C).
Minor and major: clypeus with broadly convex anterior margin and medially notched posterior margin. In profile, dorsal outline of mesosoma interrupted by metanotal suture, promesonotal suture distinct but not impressed. In profile, petiole always biconvex. Body integument opaque, densely reticulate-punctate ( Fig. 6B-D). Few scattered hairs present on mesosomal dorsum, pubescence abundant to reduced.
Remarks. The Camponotus edmondi species group can be distinguished by the combination of the following characters: dorsolateral margin of propodeum marginate or extending into a sharp ridge, propodeal declivity usually concave, anterolateral corner of pronotum most often marginate, forecoxa larger than the width of mesopleuron, and propodeal dorsum abruptly sloping down to the insertion of the petiole.

Definition of the Camponotus efitra species group
Minor worker: in full-face view, head subovate with strongly convex posterior and lateral sides. Anterior clypeal margin broadly rounded (Fig. 7A).
Major worker: in full-face view, head roughly quadrate or rectangular, head sides evenly convex (as in C. efitra) to straight (as in C. chrislaini) (Fig. 7C).
Minor and major: in profile, metanotal suture impressed, the propodeal dorsum forming a separate convexity from a domelike promesonotum, dorsum of propodeum below level of promesonotum. Clypeus evenly convex to straight in profile, its anterior margin convex to broadly triangular, not projecting, posterior margin weakly notched medially, major worker with massive mandible, occipital portion asetose, few standing setae present between frontal carinae but moderately present on clypeal dorsum and malar area. Petiole nodiform. Color brown. Integument sculpture finely imbricate to glabrous, apparently shiny (Fig. 7B, D).
Remarks. The efitra group is characterized by the color and sculpture of its integument; and a convex promesonotum separated from the propodeum by a weak metanotal suture. In Rakotonirina, Csősz & Fisher, 2017, C. efitra was considered a member of the grandidieri species group. Here, this species is separated from this group by the form of the mesosoma and the petiolar scale, the type of integument, and the general sculpture of major workers.

Definition of the Camponotus ellioti species group
Minor worker: in full-face view, head subtriangular, posterior margin evenly convex, head sides anterior to eyes subparallel and diverging posteriorly (Fig. 8A).
Remarks. The Camponotus ellioti species group is characterized by the following morphological features: mesosoma reddish, gaster dark brown to black; anterior clypeal margin projecting into broadly convex lobe; frontal carina short and diverging posteriorly, median carina absent; clypeus with short, rounded lobe; mandible subtriangular, apical tooth long; eyes large, elliptical, and break the lateral margin of head; in minor, head and occipital margin rounded, lateral head sides parallel before eyes.
Camponotus ellioti has been considered a member of subgenus Myrmopiromis mainly because of the dense pilosity on its gastral dorsum and the humeral angle, but after morphological investigation, we find that the color of the integument can be a good indicator for separating Malagasy Camponotus species.

Definition of the Camponotus madagascarensis species group
Minor worker: in full-face view, head elongate, lateral borders straight, feebly diverging posteriorly; posterior margin more or less convex (Fig. 9A).
Major worker: in full-face view, head rectangular, posterior and lateral borders slightly convex (Fig. 9D).
Minor and major worker: with the head in full-face view, anterior clypeal margin with an angular lobe, triangular or rectangular with rounded anterolateral angle; clypeus with median carina. In profile, dorsal line of mesosoma forms a continuous line, anterolateral corner of pronotum rounded. Petiolar node compressed anteroposteriorly and tapering dorsally; anterior face generally convex and posterior face straight. Posterior portion of the head, mesosomal dorsum, and the lateral margin of the propodeal declivity with scattered, whitish, erect hairs ( Fig. 9B, D).
Remarks. The Camponotus madagascarensis species group possesses the same characters as the Camponotus niveosetosus group, described in Rakotonirina et al. (2017); the name has been changed because these species are endemic to Madagascar. This group is morphologically well defined by the distinctive disposition of hairs on the gastral segment. Four species of this group, with the exception of C. ivadia, are historically recognized as members of subgenus Myrmopiromis. In this study, we conclude that C. madagascarensis are endemic to the Malagasy region, while C. niveosetosus, the most similar species, is from South Africa and possesses the following suite of different morphological characters: occipital margin almost straight and not distinctly convex so that the anterior margin of pronotum is distinctly roof-like in dorsal view, cuticle of the dorsum of head of major worker with distinctive sculpture pattern, mandible of major worker with seven teeth.

Definition of the Camponotus repens species group
Minor worker: in full-face view, head oval, with broadly convex posterior margin and lateral sides almost straight (Fig. 10A).
Major worker: in full-face view, head rectangular, posterior and lateral margins weakly convex (Fig. 10C).
Minor and major: with head in full-face view, clypeus carinate medially, its anterior margin forming a triangular lobe except for C. repens, which has a truncate anteromedian margin; dorsum of body covered with numerous slender, whitish, erect hairs and abundant, elongated pubescence. In lateral view, pronotum weakly convex with anterolateral portion marginate; promesonotal suture slightly depressed (Fig.10B, D). Petiole nodiform except C. claveri. Head, mesosoma, and gaster black; legs generally much lighter in color than body. Integument shiny black.

Remarks.
Workers of the C. repens group can be diagnosed by the integument being black and shiny in appearance, and the presence of erect white setae along the entire dorsum, all of which are about the same length and transversely arranged, except in C. jjacquia, which has filiform and relatively medium-sized setae. Median portion of clypeus with longitudinal carina; dorsum of mesosoma covered with numerous, slender, erect hairs of about the same length; in lateral view, petiolar node higher than long. Metanotal spiracle obvious, surrounded by shallow depression, not as in C. christi species group. The best method to discriminate between the Camponotus repens species group and all other species stated in the Rakotonirina et al. (2018) Camponotus christi species group, is to compare the anterodorsum of pronotal margin and the mesosomal pilosity. In the C. repens group, in dorsal view, the pronotal disc is rectangular and pilosity consists of thick, whitish, erect hairs. By contrast, in the C. christi group, in dorsal view, the pronotal disc is semicircular, and pilosity consists of slender, filiform hairs.

Definition of the Camponotus robustus species group
Minor worker: in full-face view, head longer than broad, lateral margins nearly straight and slightly diverging posteriorly, posterior margin broadly convex (Fig. 11A). Major worker: in full-face view, head broader than long, lateral margin slightly convex (Fig. 11C).
Minor and major worker: clypeus not produced but with a rounded anterior margin. In profile, dorsal outline of mesosoma roughly straight and broken by metanotal suture (Fig. 11B, D); mesonotum and propodeum dorsum mostly rectangular and flattened in profile view. Ant black with opaque integument, pilosity suberect and white, pubescence short but distinct.
Remarks. The Camponotus robustus species group can be distinguished by the combination of the following characters: in profile, posterodorsal face of petiole flat; anterodorsal margin of pronotum not arcuate, as in C. edmondi species group, but with broadly rounded to tuberculate humeral angle. In dorsal view, propodeum dorsum rectangular with distinct lateral margin; it forms an obtuse angle with the declivitous face. Clypeus with short anterior rounded lobe, sometimes notched medially (C. ethicus). Mesosomal dorsum complex, metanotal suture impressed. This group includes three species, two of which have been previously described as part of the C. edmondi species group. However, from Rakotonirina et al. (2016), this group can be recognized with the combination of the following characters: dorsolateral margin of propodeum marginate or extending into a sharp ridge, propodeal declivity usually concave, ante- rolateral corner of pronotum most often marginate, forecoxa larger than the width of mesopleuron, and usually propodeal dorsum abruptly sloping down to the insertion of the petiole. In addition, this species group has a prominent pronotal suture which is large and arcuate, making the characteristic form of mesonotum oval in dorsal view; propodeum dorsum mostly reduced in length and inclined towards petiole; and petiolar face distinctly convex, with at least one face, in dorsal view, resembling a handheld fan. C. ethicus and C. robustus are now placed with Mayria and form a monophyletic group with Camponotus zoro based on the morphological traits cited above.

Multivariate statistical analysis of morphometric data
The NC Clustering dendrogram revealed 14 clusters (Fig. 12). Morphometric difference between Camponotus claveri and C. maintilany, C. darwinii and C. ursus are not detected by the clustering methods. Moreover, the distribution of each species, along with some unmeasurable features such as density of hair, integument opacity, and color of hair/integument/appendages mentioned at the species description, allowed us to consider them as separate species.  Identification key to species for minor worker for Malagasy Camponotus (Mayria) Some couplets related to the 22 species that have been transferred into the subgenus Mayria are taken from Rakotonirina et al. (2016Rakotonirina et al. ( , 2017Rakotonirina et al. ( , 2018.

1
With the combination of the following characters: head broadened posteriorly, head width equal to or slightly longer than pronotal width; occipital margin straight to evenly convex; in dorsal view, pronotum subrectangular with subparallel margins; mesosoma short and high, forming a rounded V in dorsal view; in profile, propodeum dorsum flat to slightly convex, never concave; petiolar node ranging from nodiform to squamiform; body integument opaque and dull with noticeable sculpture; pilosity consists of thick setae (Fig. 2)             Mesosoma partially submarginate or marginate (Fig. 20A)  In profile, anterior margin of petiolar node convex and posterior margin either convex or roughly triangular; propodeal spiracle located on declivitous surface or at posterolateral margin of the propodeum; in dorsal view, mesonotum quite oval (Fig. 21A, 21B       In profile, anterodorsal corner of pronotum extending anteriorly into narrow edge but dorsolateral portion not marginate, junction of dorsum to lateral surface always rounded; blunt angle between dorsal margin of propodeum and declivity distinct, or the junction between both portions rounded (Fig. 30A). Antennal scape and gastral tergites I-III covered with abundant, appressed pubescence (Fig. 30B)

20
Appendages the same color as mesosoma. Body integument finely reticulate and matte; dorsal face of propodeum forms a right angle with the declivitous face (Fig. 31A)  Appendages lighter colored than mesosoma. Body integument finely imbricate, shining; dorsal face of propodeum forms a rounded angle with the declivitous face (Fig. 31)

39
Body color matte black, entire body covered with numerous, thick, whitish hairs. In full-face view, occipital margin medially convex, anterior margin of clypeus triangular. In profile, dorsum of propodeum shorter than declivitous face (Fig. 50A) (CAS). Paratypes. Two workers with same data as holotype but collection code: BLF32341, specimen code: CASENT0371026 and CASENT0840640 (CAS). Worker diagnosis. Integument entirely black, coarsely sculptured; gaster densely covered with enlarged white hairs; anterior clypeal margin with a rectangular lobe, broadly rounded medially; antennal scape flattened longitudinally; appressed, pointedoval, whitish hairs present next to the antennal insertion; dorsal face of propodeum distinctly shorter than declivitous face; only three first gastral tergites visible dorsally.
Distribution and biology. This new species is only known from Antsaraingy, a littoral forest, from 66 to 90 m in elevation, located in the northern portion of Madagascar (Fig. 70A). Nests were found underground and inside termite mounds; four colonies were collected to represent this species.
Discussion. Despite its large size, Camponotus antsaraingy may be confused with Camponotus mita and Camponotus voeltzkowii because in these three species the propodeal face of the propodeum is more reduced than the declivitous face. In C. antsaraingy the antennal segments are entirely flattened while in C. mita only the basal half is flattened; C. voeltzkowii has circular antennal segments. The pubescence on the gastral segment consists of thick, decumbent hair of the same type as the pilosity in C. antsaraingy, with short and filiform hairs on the other two species.
Worker diagnosis. Body integument matte black, finely reticulate-punctate; mesosoma and/or gastral dorsum with dense, long, and yellowish pilosity and pubescence; anterior clypeal margin with short, rounded, rectangular lobe; petiole squamiform. In lateral view, petiolar node cuneate, anterodosum straight basally and inclined dorsally to reach the flattened posterodorsal margin. Tibia tubular, not prismatic, its extensor profile with suberect setae. Head dorsum is matte, finely reticulate-punctate with sparse punctures on malar area; mesosoma striate in lateral view; in dorsal view, petiole, mesosoma, and appendages less shiny, finely reticulate-striolate except the abdominal sternite, which is more matte. Mandible finely reticulate-punctate with sparse oblique punctures. Hairs yellowish white, orange, or tawny colored, erect hairs usually abundant, at least on gastral tergite, often on vertex, occipital portion, and thorax dorsum; petiolar node with 4 pairs of hairs on its dorsum. Shiny black, with mandible and basitarsus reddish to brownish.
Distribution and biology. Camponotus darwinii is a famous species which is distributed widely across central of Madagascar, with a range extending from Ankazobe to Mount Papango, PN Befotaka Midongy (Fig. 58A). It has been collected from a wide variety of different habitats, including rainforest, montane rainforest, Uapaca forest, and Uapaca woodland as well as disturbed habitats such as urban and garden areas and cultivated land (Tavy). The species has also been found nesting inside Melia azedarach and Phellolophium madagascariense. Habitat elevations ranged from 1069-2150 m.
Discussion. Camponotus darwinii should be separable from most similar species in this group by the combination of the following characters: presence of dense hairs on mesosoma and/or gastral dorsum, mandible and malar area distinctly reddish in color, propodeal and declivitous faces unequal in length. This species is much closer to C. ursus but differs in the density of mesosomal hairs and the aspect of the petiole. In addition, C. darwinii is much more robust than C. ursus.
Worker diagnosis. Integument black; head, mesosoma, and gastral dorsum clothed with dense, whitish hairs; anterior margin of clypeus with short rectangular lobe; dorsal outline of mesosoma almost flat; dorsum and declivitous faces of propodeum unequal in length and form an obtuse angle.

Distribution and biology. Camponotus norvigi has been collected primarily by
Malaise trap and beating low vegetation, and rarely from yellow pan traps. No colonies have been collected. It is distributed mainly in montane forest, rainforest, and high-altitude rainforest in southern, western, and central Madagascar; in tropical dry forest in northern Madagascar, e.g., Res Tsingy de Bemaraha, and in gallery forest and open areas on the western portion of the island (Fig. 58B). It occurs at elevations of 20-1606 meters. This species is sympatric with C. darwinii at the edge of PN Isalo and Ranomafana, at Ambohitantely (Forêt sclerophylle).
Discussion. Camponotus norvigi stands out within the species group. The color and disposition of the erect hairs covering its entire dorsum separate C. norvigi from C. darwinii. The latter species and C. ursus both have dense pubescence on their mesosoma or gastral dorsum, a character absent in C. norvigi. At first glance, C. norvigi appears closely related to the C. madagascarensis group because of its whitish pilosity, but the two differ in the structure of the mesosoma, which is low and long in the C. madagascarensis group and short and high in the C. darwinii group.
Etymology. This species is named in honor of K. Norvig for support in training young scientists in Madagascar.

Camponotus nossibeensis André
Worker diagnosis. Integument matte black; body a rust brown color, relatively dense on entire dorsum; anterior margin of clypeus with short rectangular lobe; dorsal outline of mesosoma weakly arcuate; declivitous face of propodeum longer than its dorsum.
Distribution and biology. Camponotus nossibeensis is an endemic species mostly known from the northern part of Madagascar, from Nosy Faly to Ambanja. This species seems very adaple because it has been collected from both humid and tropical dry forest, at altitudes 7-780 m (Fig. 58C). The data indicate that individual workers forage on the ground and on lower vegetation, while nests are mostly found in dead twigs above ground, rotten logs, dead tree stumps, and underground.
Discussion. The combination of large size, big eyes, vertical declivitous face of propodeum, dense pilosity on mesosoma and gaster, and alveolate sculpture make C. nossibeensis a very distinctive species.   Figures 14B, 16D, 18C, D, 55
Worker diagnosis. Integument matte black with sparse, yellowish brown hairs arranged in a series of transverse rows, pubescence reduced to absent on mesosomal dorsum. Anterior clypeal margin with a distinct produced rectangular lobe. Petiole cuneate in profile. Description of minor worker. Medium-sized species. Absolute cephalic size (CS: 1.59±0.22, 1.43-1.77). In full-face view, head longer than broad, narrower in front than in back, with feebly convex occipital and lateral sides (CWb/CL: 0.37±0.03; 0.35-0.40). Eyes circular, placed much closer to the lateral sides (PoOC/CL: 0.08±0.01, 0.07-0.09). Mandibles triangular with six teeth. With head in full-face view, clypeus not carinate, its anterior margin produced, forming a short rectangular lobe with a sharp, lateral angle. Antennal scape circular, long, surpassing the occiput by the length of one basal funiculus (SL/CS: 0.39±0.03, 0.37-0.41). In lateral view, anterodorsal corner of pronotum broadly rounded, mesosomal dorsal almost straight, propodeal dorsum shorter than declivity, both straight in profile and meeting at a blunt angle (MW/ML: 0.21±0.02, 0.20-0.23; MPD/ML: 0.24±0.02, 0.22-0.26). Promesonotal and metanotal sutures form bold, polished lines. In lateral view, petiolar node cuneate, with a short, vertical, anterior face which reaches toward the flattened posterior faces. Head and mesosoma finely alveolate, gaster more finely strigulate. Mandible finely foveate with sparse punctures. Pilosity of dorsal head and body consists of fine and pointed brownish yellow hairs, long and suberect on frontal area and mesosomal dorsum; mostly short and sparse on gastral tergites; petiolar dorsum edge with 4 to 5 pairs of brownish yellow hairs. Body entirely matte black, apical portion of mandible, basitarsi, and funiculus reddish brown.
Distribution and biology. Camponotus radovae is mainly distributed in the southern part of Madagascar in Zombitse National Park (Fig. 58D). This species is encountered in native forest habitats such as deciduous dry forest, tropical dry forests, gallery forests, and spiny forests and thickets. It was sampled mostly from Malaise traps and by beating lower vegetation, on the ground, and twice on leaf litter at altitudes 20-840 m. Discussion. Within the Camponotus darwinii group, Camponotus radovae cannot be confused with C. darwinii or C. themistocles since the latter two differ by size and pilosity color. However, C. radovae has reduced pubescence and is smaller in size.
Distribution and biology. Camponotus themistocles has been collected at three localities in southern Madagascar (Fig. 58E): two are littoral forest and one is gallery forest. All sites are at low altitudes from 10 to 30 meters. Camponotus themistocles is a ground nester; most collections have been made from sifted litter, rotten logs, and dead twigs above the ground.
Discussion. Camponotus themistocles differs from C. radovae by its larger size and the sculpture of the lateral sides of its mesosoma, which is finely reticulate-punctate in the former and widely striolate in the later. In addition, in lateral view, the petiole scale of C. themistocles has an acute summit but is blunt in C. radovae. Pubescence is long and abundant in C. themistocles, and short and dilute in C. radovae. Morphometrical analysis reveals that C. themistocles and C. ellioti are the same size, but differ in integument coloration and pilosity pattern on the gastral tergite.
Description of minor worker. Medium-sized species. Absolute cephalic size (CS: 1.54±0.19; 1.43-1.64). In full-face view, head somewhat longer than broad, narrower in front than behind, with slightly convex lateral and posterior sides (CWb/CL: 0.37±0.02; 0.36-0.38). Eyes elliptical, sublateral at midpoint from the lateral sides (PoOC/CL: 0.07±0.02; 0.06-0.08). Mandibles triangular with six teeth. Clypeus not carinate, produced into a short, rectangular lobe. Antennal scape long, surpassing the occiput by the length of one basal funiculus. (SL/CS: 0.38±0.02; 0.37-0.39). In lateral view, dorsal contour of mesosoma smoothly convex, humeral angle broadly rounded; in dorsal view, mesonotal suture distinct but not impressed, mesonotal suture obsolete so that mesonotum and propodeum are fused together, propodeum with convex base and sloping declivity (MPH/ML: 0.18±0.02;. Petiole narrow, cuneate in profile, with short anterior face tapering dorsally to the flattened posterior face, its border rather sharp, produced upwards as a blunt angle in the middle. Head dorsum finely reticulatepunctate with shallow, sparse punctures; occipital region transversally striate-reticulate; lateral face of mesosoma, declivitous face, and petiolar face finely strigulate; legs finely reticulate; dorsum of mesosoma finely reticulate-striate-punctate with sparse excavation from which one suberect setae arises. Dorsum of gastral tergite finely striate-reticulate transversally, with sparse, small punctures. Mandible finely rugose with sparse, large punctures. Hairs golden yellow, the former abundant, long, and bending forward on entire mesosoma dorsum; suberect, short, and sparsely distributed on gastral tergites; the latter short and conspicuous on the abdominal segment, five pairs of erect hairs present on vertex. Body shiny black; scape, two basal funiculi, mandible, tarsi, and tibiae reddish. Distribution and biology. Camponotus ursus is found in two different habitats: primary forest in the eastern portion and urban/garden areas in the central highlands of Madagascar (Fig. 58F). It is found foraging on low vegetation or inside branches above the ground. It occurs at altitudes above 1,200 meters.
Discussion. Camponotus ursus is recognizable within the C. darwinii species group on the basis of its distinct mesosomal pilosity. In addition, it is the only species with reddish brown basitarsi. However, C. ursus is unlikely be confused with C darwinii for several reasons. First, the body of the latter is much larger. Second, the head and gastral segment of C. ursus are covered with fine, short, sparse, and yellowish setae, giving the ant a glossy appearance that is completely different than that of C. darwinii.
Worker diagnosis. Camponotus chrislaini can be easily distinguished from the other members of the efitra group by its mostly smooth and shiny sculpture; head more or less globose in full-face view; sigmoid frontal carina, and wavy propodeum dorsum.  tion of propodeum is raised to a blunt edge in profile, and suture forms a concavity (MW/ML: 0.22±0.02,MPH/ML: 0.17±0.02,. In lateral view, petiolar node nodiform, higher than long. Entire body, including mandible, smooth and shiny. One pair of standing hairs on angle formed by mesonotal dorsum and propodeum, head with scattered, subdecumbent, filiform brown hairs, scape with decumbent setae. Ant brownish; mandible, clypeus, and pronotum light brown; mid-and forecoxae, apical femora, basal tibiae, and apical portion of third and fourth tergite whitish. Description of major worker. Characteristics of minor workers, except: head quadrate with straight margins (CS: 1.67±0.06, 1.57-1.74; CWb/CL: 0.92±0.03, 0.90-0.96). Eyes circular, closed to the lateral margin (PoOC/CL: 0.29±0.02, 0.27-0.31). In profile, clypeus distinctly truncate (ClyL/GPD: 0.92±0.03, 0.86-0.94), its anterior margin with a short concavity in full-face view. Antennal scape same as minor but short, just reaching the occipital border (SL/CS: 0.77±0.04, 0.74-0.83). Promesonotum forms a unique dome followed by an impressed mesonotal suture, dorsum of propodeum slightly concave near the propodeal angle. Anterior portion of head with widely spaced large punctures, a single puncture in the center of the vertex. Filiform brownish hair present on head and mesosoma dorsum, more abundant on malar area.
Distribution and biology. Camponotus chrislaini is restricted to the northern portion of Madagascar (Fig. 70B). This newly identified species prefers dry (tropical dry forest, dry forest, disturbed dry forest) as well as wet (montane forest and rainforest) habitats at moderate altitudes (below 1000 m). It was primarily collected from rotten logs, sifted litter, inside trees, or on branches above ground.
Discussion. The new species is easily distinguishable from the Mayria species, but morphologically is most similar to the unidentified species Camponotus MG098 from subgenus Myrmonesites. The main character used to distinguish them is the form of the petiolar scale, as in the former the petiole is much thinner and its dorsal face forms a straight surface, while in the latter the petiole is thickened with the posterior face concave in dorsal view. Camponotus MG098 is also covered with plentiful setae which are scarce and widely distributed in C. chrislaini. The presence of C. chrislaini and C. MG098 in six localities (Sakaramy, Binara, Antsahabe, Analamerana-Ankavanana, Galoko, and Mont Kalabenono) suggests that they are reproductively isolated.
Worker diagnosis. Camponotus andrianjaka can be easily distinguished from other species of the ellioti group by the following character set: body bicolored, head and mesosoma reddish brown, gaster dark brown to black; anterior clypeal margin rounded, not produced; propodeum dorsum slightly concave at the level of metanotal suture; petiole nodiform and surmounted with standing, whitish hairs on its posterior margin.
Distribution and biology. Camponotus andrianjaka is a very distinctive species that appears endemic to Bismarckia woodland, shrubland, Uapaca woodland, and savannah woodland in the southern part of Madagascar (Fig. 70D). It can be found also on eucalyptus plantations and grassland. Altitude: 1300-1987 m.
Discussion. At first sight, Camponotus andrianjaka may be confused with another new species, Camponotus MG132, subgenus Myrmonesites, but can be separated easily with mesonotum that is gradually rounded in dorsal view; petiole higher than long, its dorsolateral margin surmounted with white hairs; presence of ground pubescence; and gaster all black. In addition, C. MG132 has been collected from rainforest and montane rainforest and absent from woodland.
Etymology. This new species is named after the collector Andrianjaka Ravelomanana. Additional material examined.  Diagnosis. Head and mesosoma reddish brown to dark brown, gaster always dark colored; anterior clypeal margin of clypeus with short, rectangular lobe; pronotal humeri tuberculate, dorsal outline of mesosoma arcuate; gastral tergite with short, decumbent, ochreous setae.
Distribution and biology. Camponotus ellioti occurs in the dry forest regions of the southeast of Madagascar in habitats such as bush, coastal scrub, and coastal spiny bush on sandy soil, Euphorbia forest, spiny bush and thicket, gallery forest, and riparian scrub (Fig. 70C). It has been collected from sifted litter and Malaise traps. The altitudes of these localities range from 5 to 230 meters.
Discussion. Camponotus ellioti is a distinctive species recognizable by the submargined anterolateral corner of the pronotum and the gaster covering of thick, blunt hairs the color of rust. In the traditional classification, C. ellioti is considered a member of the C. darwinii species group based on the density and color of the gastral pilosity and the sculpture pattern; however, we propose color as a character difference between these two groups.
Worker diagnosis. Ants bicolored: head and mesosoma reddish brown, gaster dark brown to black; pronotum and mesonotum form a unique dome followed by an impressed metanotal suture, propodeum, and petiole angle with standing, whitish, spatulate hairs, head and gastral dorsum with sparse, fine, brown hairs; petiole squamiform.
Distribution and biology. Camponotus maintilany occurs from 1300-1987 m in elevation and inhabits a montane environment in the central highlands, where it prefers mostly Uapaca forest or woodland, but is also found in savanna grassland and eucalyptus plantations (Fig. 70E). This new species has been collected by digging in soil, sifting leaf litter, and baiting with tuna fish or sardines. In addition, a few workers were found in Malaise traps.
Discussion. Camponotus maintilany is most readily distinguished from other members of the ellioti species group by a deeper metanotal groove and shinier sculpture. It may be confused with C. andrianjaka but can be separated by its impressed metanotal suture and truncate petiolar node.
Etymology. This species is derived from the coloration of the mesosoma and gaster. "Mainty" means black and "ilany" means second part.  Body finely imbricate. Hairs whitish; enlarged, whitish hairs with blunt tip on mesonotum, propodeum, and petiolar dorsum; filiform, pointed, grayish hair on head, pronotum, and gastral segment; pubescence white, short, and more abundant across entire dorsum. Head, mesosoma and gaster dark brown, femora, tibia, and funiculi brown, scape and basitarsi slightly lighter.
Distribution and biology. Camponotus ivadia has thus far been collected only in the Forêt d' Ampondrabe within Ankarana Reserve, a region with tropical dry forest located in the northern portion of Madagascar (Fig. 70F). All specimens were collected by beating vegetation.
Discussion. This species is easily recognized within the madagascarensis group as one of few back and shiny species with white standing pubescence.
Etymology. The species epithet ivadia is derived from the low vegetation microhabitat it prefers.
Worker diagnosis. Integument black; entire body with plentiful, erect setae; anterior clypeal margin produced into a rounded triangular lobe; dorsal outline of mesosoma slightly impressed at the level of metanotum; petiole long and low.
Description of minor worker. Medium-sized. Absolute cephalic size (CS: 0.99±0.14; 0.91-1.09). In full-face view, head almost quadrate (CWb/CL: 0.32  posterior face flattened along entire broad border. Body finely imbricate. Hairs whitish, one pair present on vertex, middle of mesonotum, and propodeum dorsum; two pairs on each side of lateral corner of propodeum; three pairs on lateral margins on petiole. Head and mesosoma reddish, legs light brown, basal face of first gastral segment light brown and the remaining segment dark brown to black. Description of major worker. Characteristics of minor workers, except: head as long as broad, with rather convex posterior borders and subparallel lateral sides (CS: 1.18±0.09, 1.12-1.24, CWb/CL: 0.86±0.01, 0.85-0.87). Eyes circular, placed Worker diagnosis. Integument shiny black; standing pilosity sparse elsewhere; clypeus with short, rounded lobe; mesonotal suture impressed; petiole nodiform; gaster longer than mesosoma.
Distribution and biology. Camponotus ihazofotsy is known from the dry forest of Tsimanapetsotsa and Andohaela NP (Fig. 72B). We assume that this species is arboreal because all samples were collected from Malaise traps.
Discussion. Camponotus ihazofotsy closely resembles C. tsimelahy, although morphological examination reveals a number of distinguishing characters. The most interesting character is the form and length of the petiolar scale; in C. ihazofotsy the petiole is cuboidal (anterior and posterior face about the same height), while in C. tsimelahy the posterior face is higher than the anterior face. In addition, these two species are sympatric at one site, Ihazofotsy. Molecular phylogenetic analysis provides strong evidence that they represent separate lineages (unpublished data).

Conclusion
The revision of a large genus such as Camponotus requires the integration of multiple lines of taxonomic evidence to delineate species, namely, original morphological descriptions, detailed quantitative morphological measurements, information on ecological distribution, genetic sequence data, and images of type specimens.