Echinopla melanarctos

Identification
Zettel and Laciny (2015) - Echinopla melanarctos is the type species of Echinopla. It can be easily recognized by its relatively large size (in workers TL ca. 6.5–8.2 mm, HW1 ca. 2.05–2.44 mm), very spiny appearance, long black hair, and entirely black colour (except palpi). The “spines” are slender, socket-shaped protuberances (“pedestals”) of the integument, their apex is truncate and bears a long seta, surrounded by a subapical ring of short, horizontally projecting hairs (bearing resemblance to the pappus of a dandelion seed). They are typical for a group of species also containing Echinopla pallipes, Echinopla circulus, Echinopla tritschleri, and Echinopla cherapunjiensis. In E. tritschleri, however, the ring of short setae is not horizontally projecting but oblique, therefore the pilosity is less obvious.

Due to the scarcity of specimens, hitherto little is known about the differences between workers and gynes in Echinopla. We were able to study both castes of Echinopla melanarctos and noted the following differences: body of gynes larger (TL 8.8–9.7 vs. 6.5–8.2; HW1 2.41–2.70 vs. 2.05–2.44); eyes slightly larger; ocelli present; pedestals lower than in worker, on scutum and scutellum reduced to low tubercles; these parts with coarse, irregular rugae, scutum anteriorly with distinct, long median carina; short pilosity of dorsum less obvious; thoracic structures as typical for winged ant gynes (all examined specimens with wings broken off); scutellum laterally with a short lobe (not with a sharp projection as in some congeners).

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia, Singapore. Oriental Region: Thailand.

Biology
Gnatzy & Maschwitz 2006 - Colonies (n=2) were monogynous and polydomous with less than 100 workers. Nests in dead hollow branches lying on the ground or hanging in the vegetation. Foragers did not visit any trophobionts. Scavengers collected small dead insects.

E. melanarctos have about 700 pedestal hairs, a cuticular structure unique in ants.

Nomenclature

 *  melanarctos. Echinopla melanarctos Smith, F. 1857a: 79, pl. 1, figs. 25-29 (w.) SINGAPORE.

Holotype worker in. Labelled “SINC” and with a Donisthorpe type-label. A second specimen is present in, labelled “22 SING.”