Carebara periyarensis

The only known specimens of this Indian species were manually collected beneath a stone in Medaganam region of the Periyar Tiger Reserve. The ground is heavily covered with leaf litter and has a dense canopy overhead. The region has an average daily temperature of 32°C and is comprised of intact tropical wet evergreen forest with minimum light penetration.

Identification
C. periyarensis can be differentiated from the already described species from India on the basis of antennal segment as new species have 11 segmented antenna while rest of the species have 9 segmented antenna excluding Carebara affinis and Carebara diversa having 11 segmented antenna.

Though, it can be differentiated from C. affinis on the basis of following characteristics (Fig. 7 A, B and Fig. 7 C, D)
 * Head in C. periyarensis is as long as broad (head is distinctly longer than broad in C. affinis)
 * In C. periyarensis petiole node dorsally emarginated (petiole node dorsally not emarginated in C. affinis)
 * In C. periyarensis propodeum with a pair of denticles (propodeum with a pair of distinct long spines in C. affinis)
 * In C. periyarensis head finely and longitudinally striate throughout except small smooth median area at the frontal region, pronotum dorsally with longitudinal striations and laterally with transverse striations (head feebly longitudinally striate and mostly smooth with punctures, pronotum mostly smooth with few transverse striations anteriorly in C. affinis)

From C. diversa (Fig. 7 E, F), it can be distinguished by the following combination of characteristics
 * In C. periyarensis body size not large TL (Major worker 3.54-3.76mm and Minor Worker 1.76-1.92mm) (body of C. diversa is disproportionately huge TL (Major worker 10.34-11.71mm and Minor Worker 2.08-2.57mm)
 * In C. periyarensis head is short without a median ocellus in front and propodeum with a pair of short spine (head massive and subtriangular with a median ocellus in front and propodeum with a pair of distinct long spines in C. diversa)

Distribution based on Regional Taxon Lists
Oriental Region: India.

Nomenclature

 * . Carebara periyarensis Dhadwal & Bharti, 2022: 410, figs. 1-6 (s.w.) INDIA (Kerala).

Type Material

 * Holotype (worker): India: Kerala: Periyar Tiger Reserve, 930m, 9.3230°N, 77.1315°E, 27.i.2017 [PUAC T 101].
 * Paratype; 6 (w.) with same data as holotype, Hand picking method, leg. Tarun Dhadwal [PUAC T 103-108 ].

Description
Worker

Major

Head in full face view as long as broad, posterior margin concave in the middle with occipital corners rounded, lateral sides convex anteriorly; median portion of clypeus bicarinate and divergent anteriorly, anterior margin weakly concave; mandibles with 5 teeth; antennae slender, 11 segmented with a two segmented club, scape short reaching up to half of the head length; eyes small with 3 pair of ommatidium. In profile view, promesonotum high and convex, promesonotal suture obsolete, metanotal groove deeply impressed; propodeum with a pair of short denticles; propodeal declivity slightly concave; petiole node thick and subtriangular furnished with a keel beneath; postpetiole subglobose in shape. In dorsal view, pronotum globular, large, strongly convex occupying most of mesosoma; mesonotum small, transverse, metanotum reduced; petiole emarginated; postpetiole with convex lateral sides.

Sclupture, pilosity & Color: Mandibles longitudinally striated and clypeus smooth and shiny. Head finely and longitudinally striate throughout except small smooth median area at the frontal region, occiput with transverse striations; promesonotum longitudinally striated, metanotum reticulate and propodeum reticulate with few transverse striations; lateral sides of pronotum and propodeum with transverse striations; mesopleuron reticulated; in lateral view petiole and postpetiole with transverse striations and microreticulate in dorsal view, with one or two longitudinal rugae on petiole; postpetiole dorsally smooth and gaster reticulate anteriorly and rest of gaster smooth with punctures. Head and body with abundant erect to suberect hairs; scapes and tibiae with dense decumbent pubescence. Body generally reddish yellow in color, head somewhat darker in color and legs lighter yellowish in color.

Measurements and Indices:

Holotype: HL 1.03; HW 0.98; SL 0.57; ML 0.68; EM 0.36; WL 0.94; PW 0.58; MFL 0.66; MTL 0.51; PTL 0.30; PTH 0.22; PTW 0.16; PPL 0.28; PPH 0.20; PPW 0.26; GL 0.99; GW 0.70;CI 95.14; MI 66.01; SI 55.33; MLI 64.077; PPLI 93.33; PPI s162.50; TL 3.54 mm.

Paratypes (n=2): HL 1.01-1.06; HW 0.96-0.99; SL 0.52-0.57; ML 0.65-0.75; EM 0.33-0.39; WL 0.90-0.97; PW 0.54-0.63; MFL 0.64-0.69; MTL 0.51-0.53; PTL 0.30-0.33; PTH 0.22-0.24; PTW 0.14-0.16; PPL 0.24-0.28; PPH 0.21-0.22; PPW 0.25-0.28; GL 1.09-1.12; GW 0.74-0.84;CI 93.39-95.04; MI 64.35-70.75; SI 51.48-53.77; MLI 63.36-65.09; PPLI 80.00-84.84; PPI 175-178.57; TL 3.54-3.76 mm.

Minor

All characteristics are same except; size of minor worker is small, posterior margin widely emarginated in the middle, occipital corners almost straight, slightly rounded; mandibles smooth, head feebly longitudinally striate at sides, having smooth median portion and reticulated at occipital corners; pronotum smooth feebly reticulated anteriorly, mesonotum and metanotum reticulated, mesopleuron and metapleuron minutely reticulated. Body generally with less hair as compared to major worker.

Measurements and Indices(n=4): HL 0.42-0.47; HW 0.45-0.49; SL 0.35-0.39; ML 0.28-0.31; EM 0.14-0.17; WL 0.52-0.55; PW 0.28-0.31; MFL 0.36-0.39; MTL 0.32-0.35; PTL 0.19-0.20; PTH 0.14-0.16; PPL 0.15-0.17; PPH 0.13-0.15; PTW 0.11-0.12; PPW 0.14-0.16; GL 0.48-0.53; GW 0.32-0.37; CI 104.25-107.14; MI 65.95-66.66; SI 82.97-83.33; MLI 82.97-85.71; PPLI 78.94-85.00; PPI 127.27-133.33; TL 1.76-1.92 mm.

Queen

Unknown.

Male

Unknown.

Etymology

The species has been named after the name of the Periyar Tiger Reserve.