Species: Camponotus polynesicus

Taxonomic History (provided by Barry Bolton, 2013)

Distribution:

Endemic to the Fiji Islands.
 
Beqa: Mt. Korovou 326. Gau: Navukailagi 325, Navukailagi 387, Navukailagi 415, Navukailagi 408, Navukailagi 432, Navukailagi 356, Navukailagi 496, Navukailagi 564. Kadavu:Moanakaka 60, Moanakaka 60, Lomaji 580, Namalata 100, Namalata 120, Namalata 50, Namalata 139, Buka Levu.Koro:Nabuna 115, Mt. Kuitarua 500, Mt. Kuitarua 505, Kuitarua 480, Mt. Kuitarua 485,Koro. Lakeba: Tubou 100 a, Tubou 100 c. Macuata: Vunitogoloa 10, Vunitogoloa 36. Mago: Mango.Moala:Maloku 80, Maloku 120, Maloku 1, Mt. Korolevu 375, Naroi. Munia: Munia. Ovalau: Levuka 400, Draiba 300, Wainiloca, Andubagenda, Cawaci, Vuma, Ovalau, Levuka. Taveuni: Devo Peak 1188, Devo Peak 1187 b, Lavena 300, Lavena 235, Lavena 217, Lavena 219, Lavena 229, Mt. Devo 892, Mt. Devo 1064, Soqulu Estate 140, Lavena 235, Nagasau. Vanua Levu: Mt. Delaikoro 910, Kilaka 146, Wainibeqa 53, Wainibeqa 150, Kilaka 98, Vusasivo Village 190, Drawa 270, Vusasivo 50, Vuya 300, Mt. Vatudiri 641, Mt. Delaikoro 699, Vusasivo Village 400 b, Rokosalase 180, Rokosalase 150, Rokosalase 97, Rokosalase 118, Rokosalase 94, Lomaloma 587, Lagi 300, Wainunu, Suene, Labasa, Lasema a. Viti Levu: Nabukavesi 40, Mt. Evans 800, Mt. Evans 800, Mt. Evans 800, Mt. Evans 700, Mt. Tomanivi 700 b, Navai 700, Mt. Tomanivi 700, Vaturu Dam 575 b, Colo-i-Suva Forest Park 220, Mt. Naqarababuluti 912, Naqaranabuluti 860, Suva, Vaturu Dam 700, Vaturu Dam 620, Vaturu Dam 550, Vaturu Dam 530, Mt. Batilamu 840 c, Savione 750 a, Monasavu 800, Monasavu Dam 600, Lami 200, Nakobalevu 340, Colo-i-Suva 200, Korobaba, Colo-i-Suva 460, Colo-i-Suva 325, Colo-i-Suva 372, Lami 171, Colo-i-Suva 186 d, Mt. Evans 700, Naboutini 300, Navai 1020, Nakavu 200, Nabukavesi 300, Naikorokoro 300, Veisari 300 (3.8 km N), Waivudawa 300, Nadarivatu 750, Nausori, Waiyanitu, Colo-i-Suva, Belt Road. Yasawa: Tamusua 118, Nabukeru 120.

Biology:

Camponotus polynesicus is the most abundant and ubiquitous member of the genus in Fiji. It occurs throughout the archipelago across a wide range of habitats and elevations. The morphological variation exhibited by C. polynesicus is extreme, and further study may well reveal this name to refer to multiple species. Camponotus polynesicus occurs across a wide elevation gradient, and was most often encountered in forested habitat, where it nests in dead branches, sticks, logs, and occasionally ant-plants. The species is was collected by both malaise trapping and litter sifting, and several collections were made from human-dominated landscapes.

Identification:

Camponotus polynesicus, as defined here, is a highly variable species both with regard to color and sculpturing. The color of the major workers varies from uniformly dark reddish black to yellow brown with variegated gasters. Intermediate specimens may be bicolored with a paler head and mesosoma and a strongly contrasting dark gaster. The other character showing considerable variation is the sculpture of the clypeus and cheeks.

 The large variation exhibited by these ants is almost entirely among colonies; there is virtually no variation among nestmates. It is fascinating to conjecture what types of genetic characters, gene flow and evolutionary processes have led to such a diverse array of forms. A population-level study of the complex would no doubt improve upon the inferences made with only the aids of morphology and geography. A more thorough study may well reveal that C. polynesicus, as defined here, is actually a complex of multiple species, but we are considering it a single species with highly structured populations and introgression occurring across geographical boundaries.

The type series described by Mayr was collected from Ovalau. The majors examined from Ovalau for this study have a reddish brown head and antennae, a yellow brown mesosoma and matching legs, and a contrasting dark brown gaster. The clypeus bears a well-defined median carinae that terminates before reaching the anterior border. The clypeus and the cheeks are both marked with broken longitudinal carinae. The minor workers have a yellow brown head, a pale yellow mesosoma and a contrasting dark brown gaster.

The situation on Viti Levu is quite confusing. For example, the full spectrum of color variation occurs sympatrically in Vaturu Dam area on the western part of the island. Nest series of dark specimens (e.g., CASENT0187042), strongly bicolored specimens (lighter mesosoma and head, darker gaster, e.g., CASENT0187099), and uniformly light specimens (e.g., CASENT0187262) were all collected from the exact same locality (Vaturu Dam 575 b). Although the strength of the sculpture is weakly associated with color (darker specimens with heavier sculpture), majors of all the aforementioned series exhibit a strongly-defined median carinae that extends to the apical margin of the clypeus, and all specimens exhibit longitudinal rugae on their cheeks.

The trend of color and sculpture found at the Vaturu Dam area is broken by the major workers collected from the Koroyanitu area less than ten kilometers to the west. There, the majors (e.g., CASENT0187078) are darker than any from the Vaturu Dam area, but their facial sculpture is as weak as any specimens of this group collected from the archipelago. These specimens correspond well to C. mayriella reported by Mann. The clypeus is entirely smooth except for a weak median carina that terminates well before attaining the anterior margin, and the cheeks are marked by only one or two very weak and short carinulae near their anterior margins. Although no majors of other color types were collected, the minors show the same color variation as in Vaturu Dam.

In the Nadarivatu area, the major workers (e.g., CASENT0187185, CASENT0187149) closely approximate those of the Vaturu Dam site with respect to facial sculpture, and exhibit the bicolored appearance with the lighter head and mesosoma contrasting with a darker gaster. This combination of sculpture and color approximates the description of C. maudelladescribed by Mann from Waiyanitu, and also reported from Nadarivatu and Taveuni. An aberrant single major worker (CASENT0187269) of relatively uniform yellow brown color was collected from the Monasavu Dam region. The head is larger than those of the Nadarivatu majors, and the clypeus cheeks and mandibles are covered in a dense, thickly developed rugoreticulum from which individual rugae are impossible to separate. Minor workers from the Nadarivatu area also include the uniformly light individuals that correspond to C. maudella var. seemanni Mann, described from Nadarivatu.

In Kadavu, two varieties of majors were collected. One variety [e.g., CASENT0187304] has the lighter head and mesosoma contrasting sharply with a dark gaster. The facial sculpture is defined by strong median carinae running the length of the clypeus, which, like the cheeks, is otherwise marked by weak and short rugae. The other variety [e.g., CASENT0187350] is uniformly light in color. In addition to the strong median carinae, the clypeus and the cheeks are both covered in regular, long well-defined rugae. Although dark majors are absent from the collection, there are many uniformly dark minor workers. The other minor workers collected from the island are all strongly bicolored, with the yellow brown head and mesosoma and the dark gaster. The major worker of Camponotus janussus Bolton from Kadavu was described as having a particularly long head. However, the material examined shows considerable variation in the heads of majors with respect to both the size and shape, and the differences are not deemed significant enough to warrant status as a species distinct fromC. polynesicus as defined here.

On Vanua Levu, the entire spectrum of variety is expressed. There are uniformly light colored majors (e.g., CASENT0187242) and majors with contrasting dark gasters (e.g., CASENT018712), both with well-defined carinae on the clypeus and cheeks. There are also strongly bicolored majors (e.g., CASENT018723) and uniformly dark majors (e.g., CASENT0177854) that both have a smooth clypeus (with the exception of the median carinae), and smooth cheeks. One uniformly light major from the Natewa Peninsula (CASENT0187376) even approaches the Monasavu Dam major in the amount of rugoreticulate sculpture on its clypeus and cheeks, though distinct rugae can be identified.
 
The only major examined from Taveuni has a reddish brown head and mesosoma contrasting with a darker gaster, and moderately developed facial sculpturing. Again, minor workers of all varieties are present. On Koro, nest series of a very dark form and a paler form with a dark abdomen were collected. The face of the dark form major is marked only by a median clypeal carina. The face of the paler form is much reduced in sculpture. Finally, on Gau, the darkest majors (e.g., CASENT0187106) have the most sculptured faces, while the uniformly light major (e.g., CASENT0187494) and the more bicolored major (e.g., CASENT0187940) have strongly reduced facial sculpture.

Taxon Page Images:

Plate_30_Camponotus_polynesicus (Sarnat & Economo, in press)

Taxonomic Notes:

When Mann gave the replacement name of Camponotus mayriella to Colobopsis carinata Mayr, he assigned cotype status to several series from his own collections that are housed at the MCZC (type no. 8724). The replacement name was unnecessary because Emery had previously assigned one. The designation of type status was erroneous because Mayr had already designated type specimens in his original description. Therefore, none of the material collected by Mann retains type status.

References:

Mann, W.M. (1921) The ants of the Fiji Islands. Bulletin of the Museum of Comparative Zoology, 64, 401-499.
Sarnat, E.M. & Economo, E.P. (In Press) Ants of Fiji. University of California Publications in Entomology.

Taxon Page Author History

Specimen Data Summary

Found most commonly in these habitats: 93 times found in primary rainforest, 65 times found in secondary forest, 67 times found in disturbed forest, 23 times found in forest edge, 35 times found in coastal forest, 17 times found in primary forest, 4 times found in secondary rainforest, 13 times found in rainforest, 5 times found in disturbed rainforest, 3 times found in mixed/pine secondary forest, ...

Collected most commonly using these methods or in the following microhabitats: 20 times hand collection, 1 times 5m interval winks

Elevations: collected from 1 - 1188 meters, 371 meters average

4 Specimens Imaged | View All 545 Specimens for this species

CASENT0187123

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CASENT0187250

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CASENT0280251

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CASENT0280252

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