Diacamma scalpratum

Peeters, Heraty & Wiwatwitaya (2015) excavated four complete colonies of D. scalpratum from northern Thailand. Colonies were plentiful and easy to find in a small patch of pine forest. Excavation continued to a depth of 90cm in one colony. Several workers (including one gamergate) had a large mite on the dorsum of the mesosoma. These four colonies yielded 151±109 workers (mean number ±SD) and 69±38 cocoons (range 47-101). Only one worker had gemmae in each colony, and dissections confirmed that this was the gamergate (i.e. mated and egg-laying). All workers dissected had 16-20 ovarioles, and this number is diagnostic among closely related species (e.g. another species with large workers from Thailand has 8 ovarioles).

Distribution based on Regional Taxon Lists
Oriental Region: Bangladesh, India.

Nomenclature

 *  scalpratum. Ponera scalprata Smith, F. 1858b: 84, pl. 6, figs. 21, 22 (w.) INDIA. Emery, 1889b: 496 (m.); Wheeler, G.C. & Wheeler, J. 1952c: 610 (l.). Combination in Diacamma: Mayr, 1862: 718. Senior synonym of compressum: Dalla Torre, 1893: 29; Emery, 1911d: 65. Current subspecies: nominal plus violaceum.
 * compressum. Diacamma compressum Mayr, 1879: 660 (w.) INDIA. Junior synonym of scalpratum: Dalla Torre, 1893: 29.

Ponera scalprata

Holotype worker in. Labelled “N. Ind. 54/16.” Acc. Reg.: “1854 no. 16. N. India (Sikkim, Him.) From Dr Hooker’s collection. Collected by Dr Hooker during his travels in n. India. A few of the insects were from Khasya Hills.”

A second scalprata specimen is in, but here the usual data label is missing and has been replaced by a white card square with, “Phil. N. India.” The half-written then deleted Phil (= Philippines) raises the possibility that this specimen may not be from the original type-series.