Camponotus melanus

Dumpert et al. (2006) - In Borneo a C. melanus queen without brood was the sole ant in one of five Monomorium sp. pavilions (12.3 cm length and 1.1 cm width), with the other four pavilions still being occupied by their original owners. The C. melanus containing pavilion was built out of leaf hairs in the typical nest building mode of Monomorium and contained no silk. The coccids located in both the single nest occupied by the C. melanus queen and inside the four detected Monomorium pavilions, belong to the same species (Coccus hesperidium Linnaeus, 1758). Average measurements of the four Monomorium pavilions were 12.3 cm × 1.1 cm × 0.3 cm. It is noticeable that the single nest taken over by C. melanus was enlarged in width and height (4 cm × 1.5 cm) apparently to be more suitable for the much larger Karavaievia inhabitants. Microscopic structure of the nest walls indicated that this enlargement was done by the tiny Monomorium workers (Weissflog 2001). These findings seem to represent the earliest stage of colony foundation of a Karavaievia colony. In contrast, in Camponotus micragyne, which is known from West Malaysia and Sumatra, we came upon a progressive stage of colony establishment.

Identification
A member of the subgenus Karavaievia. This group of Camponotus species is known for their monomorphic workers and their nest weaving behavior.

Dumpert (1995) - Camponotus melanus is the darkest of all Karavaievia species except Camponotus orinus which is significantly larger and much more sculptured than C. melanus. The colour of the melanus-workers varies from a uniformly dark brown (specimens from Peninsular Malaysia) to others with reddish brown head and alitrunk and dark brown gaster (melanus-workers from Borneo). With respect to sexuals there are two other Karavaievia species with uniformly dark brown females: C. orinus (Camponotus montanus Dumpert 1989) and Camponotus texens. The females of C. orinus are significantly larger and - in contrast to C. melanus - completely dull. The females of C. texens are much more shining than those of C. melanus. Compared with Camponotus asli the worker ants of C. me/anus are larger. The differences of TL, HL, and HW are highly significant (P < 0.01). Compared with Camponotus gombaki, the occipital margin of the melanus-workers is straight contrasting to a conspicuous concave occipital margin in the workers of C. gombaki. In addition, the colour and the cuticular surface are quite different in both species.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia.

Biology
General details about the biology of species in this subgenus can be found on the Karavaievia webpage.

Nomenclature

 * . Camponotus (Karavaievia) melanus Dumpert, in Dumpert, Maschwitz, et al. 1995: 92, figs. 1, 2, 5 (w.q.m.) WEST MALAYSIA.
 * Status as species: Dumpert, Maschwitz & Weissflog, 2006: 77 (in key); Pfeiffer, et al. 2011: 37.

Worker
Holotype: TL 5.5, HL 1.41, HW 1.54, CI 108.4, SL 1.54, SI 99.2, PW 0.89, OD 0.4.

Head nearly as long as broad (CI 108.4). Head sides convex, occipital corners strongly rounded, occipital margin concave. Frontal carinae slightly sinuate, reaching back to midlength of the head, with maximum diameter of 0.45 mm or about 0.29 HW. Anterior clypeal margin almost straight except a slight broad protrusion. Eyes are situated behind the midlength of the sides of the head; their maximum diameter is 0.4 mm or about 0.25 HW. Mandibles short, with lateral borders strongly curved and five subequal teeth on each masticatory border. Antennal scapes projecting beyond the occipital margin by about one third of their length. Pedicel longer than the following flagellar segments; apical flagellar segments slightly thickened.

Alitrunk with a deep impression between promesonotum and propodeum, and two raised stigmata at the deepest point of the impression. Promesonotum, seen in profile, strongly rounded and higher than the likewise rounded propodeum. Petiole with a broad base, tapering toward the apex into a narrow ridge, seen from the side. Seen from behind, the ridge is getting rather narrow on top.

Colour uniformly dark brown; head - except the yellow brown mandibles, clypeus, part of the cheeks adjacent to the clypeus, and antennal flagellum - blackish brown as well as meso-, meta-, and epinotum. Tibiae and tarsi yellow brown. Specimens from Borneo - found by A. Buschinger - are lighter in colour. They are uniformly reddish to dark brown; head- except the yellow brown mandibles, clypeus, cheeks, and antenna! flagellum - mesonotum and especially epinotum are dark to blackish brown. Surface of head, alitrunk, and gaster shining with densely located weak punctures, which are caused by a reticulated structure. Yellowish white decumbent pubescence is dense on the whole body, including scapes and legs. Longer erect and suberect yellowish white hair especially on clypeus, but also on rest of head, alitrunk, and gaster.

Paratypes: TL 5.6 ± 0.1 (standard deviation); HL 1.33 ± 0.4; HW 1.39 ± 0.08; CI 104.3 ± 2; SL 1.50 ± 0.04; SI 95.7 ± 4.3; PW 0.87 ± 0.04; OD 0.37 ± 0.01 (20 measured).

Queen
Gynetype: TL 9.1 mm; HL 2.45; HW 2.33; CI 95.15; SL 2.18; SI 106.52; PW 1.76; OD 0.65: alate female.

Head nearly as long as wide (CI 95): sides of the head convex, occipital corners rounded, occipital margin slightly convex. Eyes are situated behind the midlength of the sides of the head and relatively larger than those of gentingensis- queen (0.28 as against 0.26 x HW). Frontal carinae extend about to midlength of head. Apart from a lateral projection behind the scapal insertion, they are almost straight and slightly divergent. Anterior clypeal margin - as in all known Karavaievia- queen - with semicircular excision. Frontal area - as in C. gombaki and C. orinus (montanus Dumpert 1989) - clearly delimited and slightly more shining than the surrounding head parts. Mandibles strong, distinctly rounded on outside, and with 5 subequal teeth on inside.

Body uniformly dark brown, except the yellow brown clypeus, the adjacent parts of the cheeks, the distal antennal flagella, the coxae, trochanter, and basal parts of the tibiae. Head, alitrunk, and gaster are weakly shining and covered with weak, but dense punctures, seen under the binocular. The scanning electron micrographs reveal a reticulated structure of the cuticle. Yellowish white decumbent pubescence densely covers the whole body. Erect and suberect longer hairs occur mainly on forehead and vertex, less dense on alitrunk and gaster. Wings whitish, veins yellow brown. Petiolar profile with broad base, tapering to a transverse ridge; petiolar ridge nearly straight without median excision.

Paratypes: TL 9.1 ± 0.2 (standard deviation); HL 2.37 ± 0.05; HW 2.31 ± 0.02; CI 97.41 ± 2.4; SL 2.09 ± 0.09; SI 110.66 ± 2.2; PW 1.77 ± 0.03; OD 0.67 ± 0.013 (3 measured).

Male
Allotype: TL 4.9, HL 0.81, HW 074, CI 91.2, SL 0.9, SI 79.5, PW 0.95, OD 0.36.

The trapezoidal head nearly as wide as long (CI 91.2), with prominent eyes, extending to the upper end of the head sides. Occipital margin strongly convex with protruding ocelli. Anterior clypeal margin almost straight, but in the middle third weakly concave. with slightly indented edges. Short frontal carinae sinuate, reaching back to midlength of head. Eyes very large; maximum diameter 0.36 mm. or nearly 0.5 HW. Scapes long, projecting beyond occipital margin of the head by more than half their length. Pedicel strongly expanded at its distal end and thicker than following flagellar segments. Head and alitrunk reddish brown, gaster dark brown and weakly shining. Under the binocular the cuticle shows dense punctures which depend on a reticulated structure, revealed by scanning electron micrographs. Wings· slightly brownish with yellow brown veins. Decumbent pubescence on head and alitrunk, denser on gaster; in addition, body provided with longer, erect hairs. Petiolar scale triangular in profile, with a broad base tapering to a ridge; ridge straight, showing no excision.

Paratypes: TL 4.9 ± 5.8; HL 0.81 ± 0.92; HW 0.74 ± 0.90; CI 91.2 ± 1 02.78; SL 0.9 ± 1.05; SI 79.5 ± 88.1; PW 0.95 ± 1.12; OD 0.36 < 0.48 (3 measured).

Type Material
Ho1otype worker, Peninsular Malaysia: Negeri Sembilan, Pasoh Forest Reserve, March/13/1992, K. Rosciszewski leg. (Naturhistorisches Museum, Basel).

Paratypes: 20 workers with the same data as holotype (2 in Museum of Comparative Zoology at Harvard University; 2 in collection of the Forest Research Institute of Malaysia . in Kepong; 2 in Museo Civico di Storia Naturale, Genova; 3 in collection of Staatliches Museum fur Naturkunde Karlsruhe; 11 in collection of the author).

Gynetype, Borneo, Sarawak, Lambir, February/28/ 1992, A. Buschinger leg. (Naturhistorisches Museum, Basel).

Paratypes: 3 queens with the same data as gynetype (1 Museum of Comparative Zoology at Harvard University; 1 in collection of the Forest Research Institute of Malaysia (FRIM) in Kepong; l in collection of the author).

Allotype male, Peninsular Malaysia, Negeri Sembilan, Pasoh Forest Reserve, March/ 1311992, K. Rosciszewski leg. (Naturhistorisches Museum, Basel).

Paratypes: 3 males with the same data as allotype (1 in Museum of Comparative Zoology at Harvard University, I in Forest Research Institute of Malaysia (FRIM) in Kepong; 1 in collection of the author).

Etymology
The name is derived from the colour of the females and some of the worker ants which are especially dark.

References based on Global Ant Biodiversity Informatics

 * Dumpert K., U. Maschwitz, A. Weissflog, K. Rosciszewski, and I. Hj. Azarae. 1995. Six new weaver ant species from Malaysia: Camponotus (Karavaievia) striatipes, C. (K.) melanus, C. (K.) nigripes, C. (K.) belumensis, C. (K.) gentingensis, and C. (K.) micragyne. Malaysian Journal of Science 16A: 87-105.
 * Dumpert K., U. Maschwitz, and A. Wesissflog. 2006. Description of five new weaver ant species of Camponotus subgenus Karavaievia EMERY, 1925 (Hymenoptera: Formicidae) from Malaysia and Thailand, with contribution to their biology, especially to colony foundation. Myrmecologische Nachrichten 8: 69-82.
 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58