Carebara acutispina

The type material was collected from a monsoon evergreen broadleaf forest.

Identification
Xu (2003) - This new species is close to Carebara wheeleri but occiput lacks transverse striations, mandible with 5 teeth, metanotal groove shallowly impressed, body smaller with TL 1.4 mm.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 *  acutispina. Oligomyrmex acutispinus Xu, 2003: 315, figs. 16-19 (s.w.) CHINA. Combination in Carebara: new combination (unpublished).

Worker
Holotype soldier. TL 1.4, HL 0.54, HW 0.40, CI 80, SL 0.23, SI 56, PW 0.23, AL 0.40, PL 0.15, PH 0.11, DPW 0.10. Paratype soldier. TL 1.4, HL 0.53, HW 0.40, CI 76, SL 0.23, SI 56, PW 0.23, AL 0.38, PL 0.13, PH 0.11, DPW 0.10 (1 individual measured), as holotype.

Body small. Head longer than broad, in full face view rectangular. Occipital margin moderately concave, occipital corners roundly prominent. Lateral sides nearly straight. Mandible with 5 teeth. Median portion of clypeus longitudinally depressed, bicarinate and divergent forward, anterior margin weakly concave. Antenna 9 segments with a 2-segmented club, apex of scape reaching to 1/2 of the distance from socket to occipital corner. Eye with 1 facet. In profile view, occiput with a pair of large acute horns. Dorsum of head weakly convex. Promesonotum high and roundly convex. Promesonotal suture obsolete on the dorsum. Metanotum absent. Metanotal groove shallowly impressed. Propodeum with a pair of acute teeth, dorsum convex at anterior portion and sloping down rearwards, declivity concave with narrow thin lateral laminae. Petiole pedunculated anteriorly, ventral face straight. Petiolar node thick, anterior face gently sloping, posterior face steeply sloping, dorsal face roundly prominent. Postpetiolar node roundly convex and lower than petiolar node. In dorsal view, petiolar node as broad as postpetiolar node.

Mandibles and median portion of clypeus smooth and shiny. Head finely reticulate, anterior 3/4 of head dorsum and anterior 1/5 of genae finely longitudinally striate. Reticulations present between occipital horns but without transverse ridge or striations. Ali trunk, petiole and postpetiole densely and finely punctate, interspace appears as fine microreticulations. Gaster smooth and shiny. Head, alitrunk, petiole and postpetiole with sparse erect or suberect hairs and dense decumbent pubescences. Gaster with sparse suberect hairs and abundant decumbent pubescences. Frontal carina with 4 erect long hairs. Scapes and tibiae with dense decumbent pubescences. Head, alitrunk, petiole and postpetiole yellow. Antennae, legs and gaster light yellow.

Paratype workers. TL 0.85-0.93, HL 0.30-0.33, HW 0.28, CI 85-92, SL0.18-0.19, SI 64-68, PW 0.18-0.20, AL 0.28-0.30, PL 0.09-0.10, PH 0.08-0.09, DPW 0.08 (5 individuals measured). As holotype, but body much smaller. Head nearly square, occiput without horns. Occipital margin shallowly concave in the middle, lateral sides weakly convex. Apex of scape reaching 2/3 of the distance from socket to occipital corner. In profile view, promesonotum weakly convex. Body in color light yellow.

Type Material
Holotype. soldier, No. A97-2591, 1380 m, Nangongshan, Mengla County, Yunnan Province, collected in the monsoon evergreen broadleaf forest by Dr. Xu Zheng-Hui on 15 Sep. 1997. Paratypes 4 workers, with same data as holotype. 1 soldier, No. A97-954, 1120 m, Guanping Village, Mengyang Town, Jinghong County, Yunnan Province, collected in the mountain rain forest by Mr. HE Yun-Feng on 7 Aug. 1997.

References based on Global Ant Biodiversity Informatics

 * Fontanilla A. M., A. Nakamura, Z. Xu, M. Cao, R. L. Kitching, Y. Tang, and C. J. Burwell. 2019. Taxonomic and functional ant diversity along tropical, subtropical, and subalpine elevational transects in southwest China. Insects 10, 128; doi:10.3390/insects10050128
 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Xu Z. H. 2003. A systematic study on Chinese species of the ant genus Oligomyrmex Mayr (Hymenoptera: Formicidae). Acta Zootaxonomica Sinica 28: 310-322.
 * Xu Z. 2003. A systematic study on Chinese species of the ant genus Oligomyrmex Mayr (Hymenoptera: Formicidae) Acta Zootaxonomica Sinica 28(2): 310-322.