Camponotus belumensis

This species belongs to the Camponotus subgenus/species-group Karavaievia of southeast Asia. Most Karavaievia species are weaver ants that build their nests with silk. Biological details of this group and some of its constituent species can be found on the Karavaievia page.

Identification
Dumpert (1995) - The worker ants of C. belumensis are very similar to those of Camponotus asli. Both are uniformly yellowish brown in colour and distinctly shining. They, however, differ significantly in the width and length of their heads: C. asli: HL 1.21 ± 0.07 (standard deviation), HW 1.21 ± 0.07 [6]; C. belumensis: HL I .06 ± 0.04, HW 1.08 ± 0.05. In addition, the heads of the C. belumensis-workers are a little bit wider than long (CI 104 ± 4) as against CI 100 ± 3 in C. asli [6]. Clear differences between the two species are shown by the females. Those of C. asli are uniformly covered with very fine punctures and shining, those of C. belumensis have alitrunks with strongly sculptured cuticles showing stripe-like structures on pro- and mesonotum. Compared with Camponotus micragyne, the females of C. belumensis are significantly larger and the worker ants differ in their PW: C. micragyne PW 0.8 ± 0.05 (standard deviation), C. belumensis PW 0.66 ± 0.03. Camponotus gentingensis workers differs from C. belumensis in the cuticle structure which is opaque and not at all shining and in their bigger size. Also the females of C. gentingensis are bigger than those of C. belumensis and uniformly opaque. All other Karavaievia species considerably differ from C. belumensis in their colour; these other species are much darker and quite differently coloured.

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

Nomenclature

 *  belumensis. Camponotus (Karavaievia) belumensis Dumpert, in Dumpert, Maschwitz, et al., 1995: 98, figs. 1, 7 (w.q.) WEST MALAYSIA.

Worker
Holotype: TL 4.2, HL 1.05, HW 1.1, CI 104, SL 1.3, SI 84, PW 0.65, OD 0.3. As in all Karavaievia species. head trapezoidal with rounded occipital corners: occipital margin straight and not at all concave. Head sides strongly convex. Length or head subequal to its width (CI 104). Eyes are situated behind the midlength of the sides of the head. Their maximum diameter is 0.3 mm or 0.27 HW. Frontal carinae nearly straight. apart from a slight projection behind the scapal insertion. They are slightly divergent and extend to about 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 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, broadly rounded and higher than propodeum. Propodeal profile flattened on top; dorsal part of the propodeum convex, descending part straight and considerably steeper. Petiolar scale triangular in profile, with a broad base tapering to a ridge. Ridge seen from front or behind pointed.

Colour uniformly yellow brown; head - except the dirty yellow front part- and alitrunk darker than gaster. Antennal scapes dark brown, flagella dirty yellow. Surface of head, alitrunk and gaster shining with densely located weak punctures. Decumbent pubescence is nearly lacking. Longer erect and suberect yellowish white hairs especially on the whole body.

Paratypes: TL 4.3 ± 0.2 (standard deviation), HL 1.06 ± 0.04, HW 1.08 ± 0.05, CI 104 ± 4, SL 1.3 ± 0.03, SI 84.2 ± 2.5, PW 0.66 ± 0.03, OD 0.3 ± 0.03 (13 measured).

Queen
Gynetype: TL 9.0 mm: HL 2.40: HW 2.31: CI 96.25: SL 2.15: PW 1.77: OD 0.64: dealate female.

Head nearly as long as wide (CI 96.25); sides of the head convex, occipital corners rounded, occipital margin slightly convex. Eyes are situated behind the midlength of the sides of the head. Frontal carinae extend about to midlength of head. Apart form a lateral projection behind the scapal insertion, they are almost straight and slightly divergent. Anterior clypeal margin - as in all known Karavaievia- queens - with semicircular excision. Frontal area – as in Camponotus gombaki and Camponotus orinus (montanus Dumpert 1989) - clearly delimited and as much shining as the surrounding head parts. Mandibles strong, distinctly rounded on outside, and with 5 subequal teeth on inside. Petiolar scale tapering to a ridge when seen in profile; ridge strongly rounded when seen from front or behind.

Body dark brown with reddish brown segment borders; also the front parts and the occipital corner of the head and parts of the legs (tarsi, trochanter and half of the femur) are reddish brown, coxae yellowish. All body parts shining, especially alitrunk, frontal area, and gaster. Head covered with weak but dense punctures. seen under the binocular; alitrunk with strongly sculptured cuticle showing stripe-like structures on pro- and mesonotum. Yellowish white decumbent pubescence on the whole body, erect and suberect longer hairs occur mainly on gaster, less dense on alitrunk and head.

Type Material
Holotype worker, Peninsular Malaysia, Belum/Perak, primary rain forest 320 m above sea level. 3 m above ground, March/311994 A. Weissflog leg. (Naturhistorisches Museum, Basel).

Paratypes: 13 workers with same data as holotype (2 in Museum of Comparative Zoology at Harvard University; 2 Forest Research Institute of Malaysia in Kepong; 2 in Museo Civico di Storia Naturale. Genova: 7 in collection of the author).

Gynetype queen, Peninsular Malaysia, Belum/Perak, primary rain forest 320 m above sea level, 3 m above ground, March/3/1994, A. Weissflog leg. (Naturhistorisches Museum, Basel).

Etymology
The name is derived from the Belum area in Perak in which this species was found during the expedition of the Malaysian Nature Society in 1994.