Camponotus maschwitzi

A Weaver Ant that uses silk in its nest construction.

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

Dumpert et al. (2006) - worker Only weakly polymorphic in size (TL 3.6 ± 0.4). Head, mesosoma and legs reddish brown, gaster blackish. Head as long as wide. Preoccipital margin straight. Petiolar scale pointed when seen from front or behind. Clypeus as much shiny as the rest of the head.

The head of this species is as long as wide. Other species with CI values of 100 or less than 100 are Camponotus exsectus, Camponotus overbecki, Camponotus texens, and Camponotus schoedli. Within this group the species differ considerably in their color with the exception of Camponotus schoedli and C. maschwitzi. Both species have also the same color (head, antennae and mesosoma reddish brown, gaster black). Workers of these species cannot be distinguished from each other. Gynes of these species, however, differ so much that there is enough reason to put them into two different species.

queen Frontal area as wide as high and clearly delimited from surrounding head parts. Anterior clypeal margin medially excised. Petiolar scale excised while seen from front or behind. Wholly black, except front parts of head, pronotum and legs. Gaster and legs shiny, rest of body opaque.

The frontal area of this species is as wide as high and clearly delimited. The frontal area of C. schoedli, however, is much wider than high and poorly delimited. Different from that of C. schoedli, the petiolar scale of C. maschwitzi is distinctly excised when seen from front or behind. Also the colors are quite different: The gyne of C. schoedli is blackish brown with reddish brown legs and antennae, but the gyne C. maschwitzi has head and mesosoma dark reddish brown, gaster blackish brown, and promesonotum and legs lighter.

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

Biology
Camponotus maschwitzi was found during an excursion to Borneo (Sarawak, near Miri, Lambir Park). The colony was situated in a dense primary forest on a small tree, 3.5 m in height. It consisted of 12 pavilions which were built on the undersides of leaves and distributed over eleven branches of this tree. The pavilions of this species are extremely long and narrow. The mean length of all present pavilions was 8.5 cm and the mean width was 0.96 cm, constituting a ratio of length to width of 8.85 to 1. All pavilions had only one chamber and one entrance. The interior floor of each pavilion was covered with a thin silk layer. The nest contained (unidentified) coccids as trophobionts. The colony consisted of one active queen, many worker ants and brood but no other sexuals. Some of the pupae had a thin cocoon whereas some others had no cocoon at all. The queen and 20 workers were taken for the description. (Dumpert et al. 2006)

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

Nomenclature

 *  maschwitzi. Camponotus (Karavaievia) maschwitzi Dumpert, in Dumpert, Maschwitz & Weissflog, 2006: 73, figs. 10-13 (w.q.) BORNEO.

Worker
Holotype: TL 3.95, HW 1.21, HL 1.17, Cl 103.4, OD 0.32, SL 1.29, SI 106.6, PW 0.72. Paratypes (n = 16): TL 3.6 ± 0.4, HW 1.16 ± 0.09, HL 1.15 ± 0.1, CI 100.6 ± 3.4, OD 0.3 ± 0.02, SL 1.33, SI 115.4 ± 2.6, PW 0.71 ± 0.04.

Head trapezoidal with rounded posterolateral corners; preoccipital margin straight in full face view. Head sides strongly rounded. Head as long as wide (CI 100.6 ± 3.4). Eyes situated behind midlength of head sides, maximum diameter 0.32 mm (0.26 × HW). Frontal carinae nearly straight with slight projection behind antennal insertion. Carinae slightly divergent and extend to less than midlength of head. Frontal area weakly delimited, anterior clypeal margin slightly convex. Mandibles short, with lateral borders strongly curved and five subequal teeth on each masticatory border. Antennal scapes projecting beyond preoccipital margin of about one third their length. Pedicel longer than the following flagellar segment; apical flagellar segments slightly thickened.

Mesosoma with deep metanotal groove, with two elevated spiracles at the deepest point of the groove. Promesonotum, seen in profile, broadly rounded; propodeum slightly higher than promesonotum and nearly as rounded. Dorsal and descending parts of propodeum straight; descending part steeper than dorsal one. Petiolar scale triangular in profile, with a broad base tapering to a dorsal crest. Crest pointed when seen from front or behind.

Color of head and mesosoma dark reddish brown, gaster blackish brown; promesonotum and legs lighter. Surface of head, mesosoma and gaster shiny with densely located distinct punctures especially on gaster. Clypeus as much shiny as rest of head. Decumbent pubescence and additional longer erect and suberect yellowish white hairs on all body parts.

Queen
Paratype (n = 1): TL 10.15, HW 2.43, HL 2.33, CI 104.3, OD 0.72, SL 2.18, SI 89.7, PW 1.85, OD 0.39, OD1 0.16, OD2 0.2.

Head nearly as long as wide (CI 104.3). Preoccipital margin strongly concave, posterolateral corners rounded. Sides of head slightly rounded. Eyes situated behind midlength of head sides. Frontal carinae extend to about midlength of head. Carinae almost straight and slightly divergent. Anterior clypeal margin with semicircular excision. Posterior clypeal margin medially excised. Frontal area as wide as high, shiny and clearly delimited from densely punctate surrounding head parts. Mandibles strong, rounded on outside with 5 subequal black teeth on inside. Petiolar profile with broad base tapering to a transverse crest. Petiolar crest distinctly excised when seen from front or behind. Head and body uniformly black in color. At most, small parts of head, mesosoma, antennae or legs lighter. All body parts densely punctate, shiny and covered with decumbent pubescence and additional longer erect and suberect hairs.

Type Material
Holotype worker : Malaysia, Sarawak (Borneo), near Miri, Lambir Park, 1.I.2003, leg. U. Maschwitz. Paratypes with same data as holotype, 16 workers (2, 2 , 2 , 3 , 7 CKD), 1 queen (NHMB).

Etymology
The name is derived from Ulrich Maschwitz, who found most of the newly described species as well as most of the previously described Karavaievia species.

References based on Global Ant Biodiversity Informatics

 * 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.
 * Dumpert, K., U. Maschwitz, and A. Weissflog. "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 (2006): 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