A new carpenter ant, Camponotus parabarbatus (Hymenoptera: Formicidae) from India

Abstract A new species of carpenter ant, collected in the Shivalik range of Himalaya is described and illustrated based on the worker and gyne castes under the name Camponotus parabarbatus sp. n. Presence of dense, short setae on gena and ventral surface of head resembles it most to Camponotus barbatus Roger, 1863 distributed in Southeast Asia. A regional identification key of Camponotus species is provided from the Shivalik hills of Indian Himalaya.


Introduction
Carpenter ants are among the largest and most common ants in the world and are found in all biogeographical regions (Bolton 2012, Bolton et al. 2007. Currently 1,058 species, 495 subspecies and 31 fossil species of Camponotus are known worldwide (Bolton 2012), with 62 species and subspecies reported from India (Bharti 2011). Despite their large size and abundance, carpenter ants are difficult to identify. Although Karmaly and Narendran (2006) compiled the Camponotus of India, their taxonomy in India remains problematic and chaotic. Taxonomy of Camponotus in India needs attention as Bharti (2011) highlights major changes in the taxa included earlier by Karmaly and Narendran (2006). The significant contributions pertinent to this study include Bingham (1903), Menozzi (1939), Morisita et al. (1991), Wu and Wang (1995), Radchenko (1996), Zhou (2001), Karmaly and Narendran (2006) and Terayama (2009). Here we describe a new Indian species, Camponotus parabarbatus sp. n., collected in Shivalik range of Northwest Himalaya. An identification key of Camponotus species is provided from the Shivalik hills of Indian Himalaya.

Materials and methods
The specimens were collected by hand in the foothills of Indian Himalaya, the Shivalik range. Specimen examination was conducted with a Nikon SMZ 1500 stereomicroscope. For digital images, an MP evolution digital camera was used on the same microscope using Auto-Montage (Syncroscopy, Division of Synoptics, Ltd.) software. These images were processed with Adobe Photoshop CS5. Holotype and paratypes have been deposited in PUPAC, Punjabi University Patiala Ant Collection, Patiala. One paratype will be deposited at BMNH, Natural History Museum, London, UK and one at California Academy of Sciences, San Francisco, USA. Morphological definitions for measurements (accurate to 0.01 mm) include: PL (Petiole Length) -In profile, the maximum length of the petiole node, measured in a straight horizontal line from immediately above the dorsal base of the anterior petiolar tubercle to the posterior margin; mTbL (midtibia Length) -maximum length of midtibia in lateral view, with tibial base and apex in the same plane of focus, and with tibia at right angle to femur; hTbL (hindtibia Length) -maximum length of hindtibia in lateral view, with tibial base and apex in same plane of focus, and with tibia at right angle to femur; GL -length of the gaster in lateral view from the anteriormost point of first gastral segment to the posteriormost point of the last segment.   Head: Head subtriangular, longer than wide in major worker (HW/HL = 0.86, n = 1), with arched margins laterally, posterior margin shallowly concave (Fig. 1a), distinctly elongate in minor worker (HW/HL = 0.75-0.77, n = 10), subrectangular with subparallel lateral margins and convex posterior margin; frontal carinae sinuous; clypeus in fullface view with anterior margin projected beyond anterior margin of gena; anterolateral corner of clypeus forming right angle, carinate in major worker, in minor worker clypeus relatively less carinate, with anterior margin only slightly extending beyond anterior margin of gena, anterolateral corner broadly rounded; scape short (SL/HW = 0.68), fails to reach occipital margin in major worker, distinctly elongate in minor worker (SL/ HW = 1.18-1.44) surpassing posterior margin by about 0.33 of its length; mandible with six teeth in minor and seven in major with seventh tooth reduced.
Vestiture: Pilosity yellowish; head, mesosoma, and all gaster segments with dense, erect, long setae; gena, entire ventral surface of head and mandible with dense shorter erect and suberect setae; scape with short, subapressed hairs; hindtibia without row of spiny bristles on ventral margin in addition to 3-4 suberect setae at distal end near spurs; body covered with very short, appressed, white pubescence, more distinct on head and gaster.
As in major worker, with modifications expected for caste and the following differences: head more elongate, sides relatively straight, occipital margin convex; mandible, clypeus and gena brownish. Head narrower than in conspecific major workers; mandible 7 toothed; scape barely reaches the posterior margin of head. Reticulate sculpture more pronounced on head; scutum with scattered wide, shallow punctures. Propodeum dorsum forms right angle with declivity.

Etymology
The species epithet parabarbatus is a compound word meaning "similar to barbatus".

Distribution
This species seems to be rare in the Shivalik range of Northwest Himalaya although collected from both forested and non-forested areas of the region. collected from vegetation while gynes and some workers were found under a large stone.

Notes
Camponotus parabarbatus resembles to the C. barbatus distributed in Southeast Asia (Bolton et al. 2007) but can be easily distinguished from the latter. The head of the major worker of C. parabarbatus is subtriangular with a shallowly concave posterior margin, the eyes well within the lateral cephalic margins, and the scape barely touches the posterior margin of head, while in C. barbatus majors the head is subrectangular with gently convex posterior margin, eyes almost touching the lateral cephalic margins, scape surpasses the posterior margin of head by about 0.25 of its length. In C. parabarbatus minor workers, the scape surpasses the posterior margin of head by about 0.33 of its length, whilst in C. barbatus the scape does so by half its length. Additionally, C. parabarbatus is uniformly jet-black whereas C. barbatus is red brown in color.