Polyrhachis monteithi

Polyrhachis monteithi builds nests of silk and vegetation debris between the leaves of low rainforest trees and shrubs. It has also commonly been collected in relatively small rainforest patches and gallery forests along rivers and creeks.

Identification
Polyrhachis monteithi is charactersed by a distinctly hairy appearance that is shared by only one other Australian species, Polyrhachis pilosa. Polyrhachis monteithi differs by its larger size (HL 1.43-1.72 versus 1.34-1.43 in P. pilosa) and distinct propodeal spines that are completely absent in P. pilosa (Kohout 2006)

Distribution
The known distribution of Polyrhachis monteithi extends from about Cooktown south to Mackay.

This taxon was described from Australia.

Abundance
One of the most common Cyrtomyrma species in rainforests of north Queensland.

Castes
Males and immature stages (eggs, larvae in various stages of development and pupae) deposited in the spirit collection.

Worker
Dimensions (holotype cited ﬁrst): TL c. 6.50, 5.54-6.75; HL 1.68, 1.43-1.72; HW 1.64, 1.43-1.65; CI 98, 94-100; SL 2.06, 1.75-2.12; SI 126, 119-130; PW 1.31, 1.09-1.40; MTL 2.40, 1.96-2.46 (19 measured).

Clypeus in proﬁle almost straight, weakly rounding posteriorly into moderately impressed basal margin. Frontal triangle indistinct. Frontal carinae sinuate with weakly raised margins; central area with weakly indicated frontal furrow. Sides of head in front of eyes almost straight, converging anteriorly and rounding into mandibular bases; behind eyes sides rounding into convex occipital margin. Eyes convex, in full face view breaking lateral cephalic outline. Ocelli lacking, relative positions indicated by shallow but distinct depressions in cephalic sculpturation. Pronotum in dorsal view widest across narrowly rounded or bluntly angular humeri. Mesosoma in lateral view evenly convex; promesonotal suture distinct; position of metanotal groove weakly indicated by shallow depression in lateral outline; propodeum armed with pair of rather strong, diverging, blunt spines; propodeal declivity almost vertical. Petiole with anterior face weakly convex, posterior face rather strongly convex; dorsum armed with four acute spines, medial pair closer to each other than to lateral spines; lateral pair more slender, longer and strongly diverging. Subpetiolar process acute anteriorly, bluntly angular posteriorly. Anterior face of ﬁrst gastral segment lower than height of petiole, widely rounding onto dorsum of segment.

Mandibles ﬁnely, mostly longitudinally rugose. Head, mesosoma, petiole and gaster ﬁnely shagreened with numerous minute punctures and piliferous pits. Sculpturation relatively ﬁne on dorsa of head, mesosoma and gaster; intensity of sculpturation distinctly increasing laterally with sides of mesosoma distinctly reticulate and meso- and metapleurae rather strongly reticulate-rugose. Anterior face of petiole ﬁnely, mostly transversely reticulate dorsally, becoming reticulate-rugose on lower parts.

Distinctly hairy. Numerous curved and semierect hairs arising from mandibular masticatory borders, numerous, very short, appressed hairs towards mandibular bases. Anterior clypeal margin with several long, anteriorly directed setae medially and fringe of shorter setae decreasing in length laterally. Several medium to long, erect or somewhat curved, mostly paired hairs near anterior and basal clypeal borders, along frontal carinae and on vertex. Tuft of several hairs on summit of mesonotum with longest hairs reaching greatest diameter of eye in length. Numerous erect, medium length hairs on dorsal and ventral surfaces of gaster. Short, dense, appressed, decumbent or semierect pubescence on most body surfaces, distinctly diluted behind eyes towards occipital corners.

Colour. Black, including antennal scapes, coxae and tarsi. Trochanters, femora and tibiae distinctly light to medium reddish-brown with proximal ends of tibiae a shade darker.

Queen
Dimensions: TL c. 7.11-7.76; HL 1.65-1.87; HW 1.56-1.75; CI 93-98; SL 2.03-2.18; SI 123-130; PW 1.62-1.78; MT: 2.46-2.71 (5 measured). Apart from sexual characters, similar to worker except: pronotal humeri evenly rounded; mesoscutum distinctly wider than long with lateral margins converging anteriorly, forming narrowly rounded anterior margin; median line distinct; parapsides ﬂat anteriorly, raised posteriorly; mesoscutum in proﬁle with anterior margin widely rounded, dorsum ﬂat. Mesoscutellum in proﬁle weakly convex, marginally raised above dorsal plane of mesosoma; metanotal groove distinct. Propodeum armed with pair of distinct, dorsoventrally ﬂattened, blunt spines. Lateral petiolar spines more slender and longer than dorsal pair. Sculpturation, pilosity and colour virtually identical to that in worker.

Male
Undescribed.

Type Material
Holotype (QMT99338), 6 paratype workers, 4 paratype queens, paratype males (from holotype nest) and most paratype workers and paratype queens in ; 3 paratype workers, 1 paratype queens (from holotype nest) and 2 paratype workers each in, and ; 2 paratype workers each in , , , ,  and.

Type Locality Information
HOLOTYPE: QUEENSLAND, Garradunga, Seymour Ra., c. 7km N of Innisfail, 17°28’S, 146°01’E, <100m, 5-6.vi.1996, lowland rf., R.J. Kohout acc. 96.30 (worker). PARATYPES: data (and nest) as for holotype (12 workers, 7 alate queens, 15 males); data as for holotype, except RJK acc. 96.22 (75 workers, 2 dealate, 2 paratype alate queens).