Pseudolasius machhediensis , a New Ant Species from Indian Himalaya ( Hymenoptera : Formicidae )

Pseudolasius machhediensis sp. nov. is described from India. This marks the second species of this genus reported in India, with only Pseudolasius familiaris (F. Smith) described earlier. An identification key to worker caste is provided to separate the Indian species.


INTRODUCTION
The genus Pseudolasius Emery, 1887 is currently represented by 45 species and 15 subspecies from the world (Bolton 2012).The Pseudolasius ants are known for polymorphic worker caste, with most of the species having major and minor workers (LaPolla 2004).
During the course of present study one new species has been recorded from Himalaya and this differs considerably from already described species of this genus.Prior to this study, only one species had been recorded from India (Bharti 2011).With the current addition 2 species signify the genus Pseudolasius from India.A key for the worker caste of Indian species has been provided.

MATERIALS AND METHODS
The specimens were collected by handpicking method.The taxonomic analysis was conducted on a Nikon SMZ 1500 stereo zoom microscope.
For digital images, an MP evolution digital camera was used on the same microscope with Auto-Montage (Syncroscopy, Division of Synoptics, Ltd.) software.Later, images were cleaned as per requirement with Adobe Photoshop CS5.Holotype and paratypes of the species have been deposited in PUPAC, Punjabi University Patiala Ant Collection, Patiala.Morphological terminology for measurements (given in millimeters) includes: HL-Head length: The length of the head capsule excluding the mandibles, measured in full face view in a straight line from the middle of the anterior clypeal margin to the middle of the occipital margin.
HW-Head width: The maximum width of the head in full face view behind the eyes.
SL-Scape length: The maximum straight line length of the scape, excluding the basal constriction or neck that occurs just distal of the condylar bulb.
Mesosoma and Petiole: Mesosoma with weakly convex promesonotal dorsum, broadest across humeral angles; pronotum convex with the sides round, mesonotum and metanotum with the sides somewhat flat; promesonotal and  mesometanotal sutures quite distinct; petiolar node with the sides more or less round, apex thin and more or less emarginate; legs stout and fairly long.
Sculpture: Head roughly smooth except for the microreticulated sculpture visible at the higher magnification; mandibles distinctly rugulose more so towards the apex; punctures and tubercles scattered all over the body; clypeus smooth and much more shiny; sculpture of mesosoma as in head; abdomen smooth and somewhat shiny.
Pilosity: Body clothed with silky yellow pubescent hairs and longer and shorter outstanding hairs; pubescence is more on head and mesosoma.
Color: The species is pale yellow in color but in some specimens the head is darker and the abdomen brown; the teeth and eyes are black and the legs yellow.
Mesosoma and Petiole: Mesosoma with weakly convex promesonotal dorsum, broadest across humeral angles; pronotum convex with the sides round, mesonotum and metanotum with the sides somewhat flat; promesonotal and mesometanotal sutures quite distinct; petiolar node with the sides more or less straight, apex thin and emarginate; legs stout and fairly long.
Gaster: Gaster long, oval, narrowed in front and behind, pointed at apex.Sculpture: The sculpture is same as that of the major workers.The minors are more shining all over; the whole body is much smoother than the major workers; mandibles distinctly rugulose all over; punctures and tubercles scattered all over the body; clypeus smooth and shiny.
Pilosity: Longer and shorter outstanding hairs scattered all over the body; the minor workers are quite deficient of pubescence, the pubescence is not as much as in case of major workers and is denser on the head.
Color: The color varies from light yellow to pale yellow with a darker abdomen; the teeth and eyes are black.lighted forested areas with scarce undergrowth and in all the cases specimens were collected under stones by hand picking.

Etymology:
The species is named after the type locality, Machhedi.

Remarks:
(Based on major workers) The species is significantly different from all other reports of this genus.Pseudolasius machhediensis sp.nov.somewhat resembles the Chinese Pseudolasius bidenticlypeus Xu, 1997 but can be easily distinguished from the latter.In Pseudolasius machhediensis sp.nov. the 4 th tooth is larger than the 5 th and 6 th teeth and the clypeus is smooth without any denticle, whereas in Pseudolasius bidenticlypeus the 4 th tooth is smaller and the clypeus is with one blunt denticle at each side.It is different from Pseudolasius familiaris (F.Smith), the only species reported from India and can be easily separated from it, as in Pseudolasius familiaris the teeth are five in number with 4 th and 5 th combined, but in Pseudolasius machhediensis sp.nov., the teeth are six in number with the 5 th and 6 th combined, the head is weakly emarginate and the antennae are much longer.