Camponotus khaosokensis

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 Strongly polymorphic in size (TL 4.6 ± 1.6). Petiolar scale broadly rounded when seen from front or behind. Propodeum angular on top, promesonotum rounded. In contrast to the shiny surface of nearly the whole body, clypeus strongly sculptured and opaque.

C. khaosokensis is dark in color like Camponotus melanus. They differ from each other in the shape of the petiolar scale. The petiolar scale of C. khaosokensis is rounded when seen from front or behind instead of pointed. In this respect, C. khaosokensis differs also from Camponotus exsectus, Camponotus overbecki, Camponotus texens, Camponotus schoedli and Camponotus maschwitzi.

queen Frontal area wider than high and poorly delimited. Posterior clypeal margin straight and not medially excised. Preoccipital margin strongly concave, petiolar scale seen from front or behind narrowly rounded, dark brown to black in color and shiny.

Similar to Camponotus asli and Camponotus weissflogi, the frontal area of C. khaosokensis is wider than high. Unlike C. asli and C. weissflogi the posterior clypeal margin is not medially excised.

Distribution based on Regional Taxon Lists
Oriental Region: Thailand.

Biology
A single colony of C. khaosokensis was detected in the Khao Sok National Park (Thailand) on an unidentified tree about 5 m in height. The colony consisted of 145 pavilions concentrated on three separate branches with a mean length of 10.47 cm and a mean width of 1.66 cm, ratio of nest length to nest width: 6.3 to 1. All pavilions were built on the undersides of leaves. The interior floor of the pavilions was covered with a thin silk layer. In addition to numerous adult workers, we found two wingless queens and a few larvae, but no other sexuals and no pupae. Both females 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

 * hoelldobleri. Camponotus (Karavaievia) hoelldobleri Dumpert, in Dumpert, Maschwitz & Weissflog, 2006: 71, figs. 5  9 (w.q.) THAILAND. Junior primary homonym of hoelldobleri Cagniant, above. Replacement name: khaosokensis Dumpert, 2006: 89.
 *  khaosokensis. Camponotus (Karavaievia) khaosokensis Dumpert, 2006: 89. Replacement name for hoelldobleri Dumpert, in Dumpert, Maschwitz & Weissflog, 2006: 71. Junior primary homonym of hoelldobleri Cagniant, 1991a: 37.

Worker
Holotype: TL 4.88, HW 1.36, HL 1.25, CI 108.8, OD 0.34, SL 1.33, SI 97.8, PW 0.83. Paratypes (n = 20): TL 4.6 ± 1.6, HW 1.44 ± 0.22, HL 1.37 ± 0.21, CI 105.3 ± 3,7, OD 0.39 ± 0.012, SL 1.54 ± 0.125, SI 106.5 ± 11.3, PW 0.88 ± 0.135.

Head trapezoidal with rounded posterolateral corners; preoccipital margin concave in full face view. Head sides strongly rounded. Head slightly wider than long (CI 108.8). Eyes situated behind midlength of head sides; maximum diameter 0.34 mm or 0.25 × HW. Frontal carinae nearly straight with slight projection behind antennal insertion. Carinae slightly divergent and extend to less than midlength of head. Anterior clypeal margin straight. Mandibles short, with lateral borders strongly curved and five subequal teeth on each masticatory border. Antennal scapes projecting beyond preoccipital margin by about one third of length. Pedicel longer than 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 and higher than propodeum. Propodeal profile angular on top; descending part steeper than dorsal one. Petiolar scale triangular in profile, with broad base tapering to a crest. Crest pointed when seen from front or behind.

Color of mesosoma and legs uniformly light reddish brown, head and gaster darker. Surface of head, mesosoma and gaster shiny with densely located weak punctures. Clypeus strongly sculptured and opaque. Decumbent pubescence on all body parts. Additional longer erect and suberect yellowish white hairs on all parts of body.

Queen
Paratype (n = 1): TL 10.69, HW 2,67, HL 2.67, CI 100, OD 0.68, OD1 0.44, OD2 0.20, SL 2.26, SI 84.6, PW 1.78.

Head as long as wide (CI 100); sides of head nearly straight. Eyes situated behind midlength of head sides. Frontal carinae extend about to midlength of head. Carinae almst straight and slightly divergent. Anterior clypeal margin with semicircular excision. Frontal area relatively small, wider than high, poorly delimited and strongly shiny in contrast to densely punctate surrounding head parts. Posterior clypeal margin straight and not medially excised. Mandibles strong, rounded on outside with 5 subequal black teeth on inside. Petiolar profile with broad base tapering to dorsal transverse crest. Petiolar crest broadly rounded when seen from front or behind.

Uniformly dark brown to black in color. Head, mesosoma, antennae, and legs densely punctate and shiny. Decumbent pubescence and additional longer erect and suberect light hairs on all body parts.

Type Material
Holotype worker : Thailand, Khao Sok Park, 27.XII.1998, leg. U. Maschwitz. Paratypes with same data as holotype, 20 workers (2, 2 , 2 , 3 , 11 CKD), 1 queen (NHMB).

Etymology
The name is derived from the great myrmecologist Bert Hölldobler.