Proceratium relictum Mann, 1921

Garcia, Francisco Hita, Sarnat, Eli M. & Economo, Evan P., 2015, Revision of the ant genus Proceratium Roger (Hymenoptera, Proceratiinae) in Fiji, ZooKeys 475, pp. 97-112 : 102

Taxon classification Animalia Hymenoptera Formicidae

Proceratium relictum Mann, 1921 Figs 1C, F, 2B, 4, 6

Proceratium relictum Mann, 1921: 413. [see also: Baroni Urbani and de Andrade 2003: 306; Sarnat and Economo 2012: 167]

Type material.

Syntypes, pinned workers and queen, FIJI, Taveuni, Somosomo (W.M. Mann) (MCZC, USNM) [examined].

Non-type material examined.

FIJI: Taveuni, Mt. Devo, 3.6 km SE Tavuki Village, -16.83056°, -179.97433°, 734 m, garden/forest edge, on ground, foraging, hand collection, 22.III.2005 (E.M. Sarnat); Vanua Levu, Mt. Delaikoro, Delaikoro Rd., 3.6 km SE Dogoru Village, -16.57525°, 179.31638°, 699 m, primary rainforest, 31.VIII.2006 (M. Tokotaa); Vanua Levu, 1.5 km N Yasawa Village, -16.46806°, 179.64362°, 300 m, disturbed forest, 1.IX.2003 (A. Rakabula).

Diagnosis.

The following combination of characters separates Proceratium relictum from the remainder of the Proceratium silaceum clade: comparatively large species (HW 1.03; WL 1.38); in full-face view head approximately as long as wide (CI 101); lateral expansions of frontal carinae weakly triangular and moderately rounded; petiolar node extremely squamiform (DPeI 620) and strongly narrowing from base to apex; subpetiolar process thickly spiniform.

Worker measurements

(N=1). TL 4.45; EL 0.04; SL 0.78; HL 1.01; HLM 1.28; HW 1.03; WL 1.38; HFeL 0.98; HTiL 0.71; HBaL 0.67; PeL 0.83; PeW 0.52; DPeI 620; LT3 0.69; LS4 0.42; LT4 1.02; OI 4; CI 101; SI 77; IGR 0.41; ASI 148.

Distribution and biology.

Proceratium relictum seems to be restricted in its distribution to the two northern islands Taveuni and Vanua Levu. Tentatively associated males collected from malaise traps support this restricted distribution and absence of the species from Viti Levu. The species appears to be tolerant of at least moderate levels of disturbance as it was collected from rainforest, disturbed forest, and forest edge garden. Collections of workers are rare and there is no available information about its natural history.

Taxonomic notes.

Proceratium relictum and Proceratium oceanicum form a very close species pair easily distinguishable from the new species Proceratium vinaka and all other Proceratium species by the extremely modified petiolar node. Detailed information on how to separate Proceratium relictum from Proceratium oceanicum is presented in the species account of the latter and the identification key.