Proceratium gibbosum

This species nests in the forest floor and the colonies are probably small. It can be found in wet evergreen and secondary tropical rainforests, nesting in the interphase of soil and leaf litter or in the debris along sheltered edges of decaying logs on floor (Image 6). Workers are solitary foragers and move at a slow pace. They feign dead when disturbed, camouflaging against the soil (Image 5D). In captivity, the workers readily accepted spider eggs as food (Image 5E) and built a nest chamber with spider silk and soil. Workers were slow in movement, looked generally uncoordinated and were averse to light. Other species that were found in the same microhabitat of Proceratium gibbosum were Tyrannomyrmex alii, Protanilla sp., Discothyrea sp., and Recurvidris sp. So far, this species is restricted to the mid-elevation tropical evergreen jungles of the Periyar Tiger Reserve, in Kerala, India.

Distribution based on Regional Taxon Lists
Oriental Region: India.

Nomenclature

 * . Proceratium gibbosum Sadasivan & Kripakaran, 2022: 21371, figs. 2A–C (w.) INDIA (Kerala).

Type Material

 * Holotype: NRC-AA-3758, 23 May 2016, Worker, Vallakadavu, Periyar Tiger Reserve, Idukki District, Kerala State, India, at 900 m, coll. by Kalesh Sadasivan, tray-sifting loose soil under a decaying log, in forest floor of a primary evergreen forest, deposited in the insect collection facility of the NCBS (National Centre for Biological Sciences), Tata Institute of Fundamental Research, GKVK, Bellary Road, Bengaluru, Karnataka 560065, India. Earlier, the holotype was with number TARG-1007, mounted for morphological study and later removed & preserved as wet specimen in absolute alcohol, deposited in the research collections facility at the Travancore Nature History Society (TNHS), Thiruvananthapuram, Kerala.
 * Paratype workers (n = 3) (Images 3–5):
 * NRC-AA-3759, 28 March 2021, Worker, Vallakadavu, Periyar Tiger Reserve, Idukky District, Kerala State, India, at 930 m, coll. Kalesh Sadasivan, tray-sifting leaflitter, in forest floor of a primary evergreen forest, deposited in the insect collection facility of the NCBS (National Centre for Biological Sciences), Tata Institute of Fundamental Research, GKVK, Bellary Road, Bengaluru, Karnataka 560065, India. Earlier, paratype number TARG-1008, preserved in absolute alcohol and currently deposited in the research collections facility at the TNHS, Trivandrum, Kerala.
 * Two other paratype workers, same data as paratype above. One paratype (TARG-1009) and (TARG-1010) both in absolute alcohol, to be deposited in the insect collection of Zoological Survey of India (ZSI), Kozhikode, Kerala.