Polyrhachis (Myrma) illaudata Walker, 1859

Material examined. Bukit Timah, Hindhede Drive, 17 Apr 1988, H.K. Lua leg., ZRC _ ENT00000331; Bukit Timah Nature Reserve, BT 01, 1.35764, 103.77491, 1 Feb 2017, W. Wang leg., WW-SG17-039, ZRC _ ENT00007569; Bukit Timah forest, 3 Nov 1973, D.H. Murphy leg., ZRC _ HYM_0000854, 857-860; Bukit Timah Nature Reserve, BT 05, 1.35386, 103.77988, ZRC _HYM_0001753; Bukit Timah (University Campus), 7 Nov 1977, D.H. Murphy leg., ZRC _HYM_0000861; Commonwealth Road, 1.31115, 103.78171, 22 Nov 2016, G.W. Yong coll., tree trunk, CW2TH668, ZRC _ HYM_0001589; same locality and collector as previous, 24 Nov 2016, CW3TH708, ZRC _ HYM_00001592; Kranji Road, 1.42638, 103.75413, 10 Nov 2016, G.W. Yong leg., KR10GH1560, ZRC _HYM_0001597; MacRitchie Reservoir, 9 Jan 2014, Sk. Yamane leg., ZRC _HYM_0000389; Mandai Road, M 3D, 1.41119, 103.80513, Nov-Dec 2016, G.W. Yong leg., ZRC _HYM_0001593-1594; Mandai Road, M 1D, 1.41258, 103.79839, Nov-Dec 2016, same collector as previous, ZRC _HYM_0001599-1600; same locality as previous, 4 Oct 2018, W. Wang leg., ZRC _ ENT00047826; Prince George’s Park Residences (NUS), 1.292389, 103.778694, 6 May 2015, M.S. Foo & W. Wang leg., malaise trap, NUS0021, ZRC _ BDP0041454, 41412; Seletar Link, SL 3, 1.40518, 103.88555, 18 Oct 2016, G.W. Yong leg., ZRC _HYM_0001595-1596; Sunset Way, 1.32609, 103.77187, 29-31 Aug 2016, G.W. Yong leg., ZRC _HYM_0001553; same locality and collector as previous, 21-23 Sep 2016, ZRC _HYM_0001590-1591; Upper Peirce Reservoir headquarters [sic], 10 Jan 2014, Sk. Yamane leg., ZRC _HYM_00000390; Upper Thomson Nature Park, 1.38311, 103.79839, 19 Oct 2016, G.W. Yong leg., UT5GH1640, ZRC _HYM_0001598 .

Material not physically examined. Non-types, FMNHINS0002842133, tc1357712761; FMNHINS0003259695, tc1357712757 (FMNH); Harbourfront, Marang Trail, 4 Aug 2014, J.K. Wetterer leg., vial #473 (JKWC) .

Literature. Tan & Corlett (2012).

Localities. Bukit Timah Nature Reserve; Bukit Timah (University Campus); Commonwealth Road; Kranji Road; Harbourfront; MacRitchie Reservoir; Mandai Road; Prince George’s Park Residences (NUS); Seletar Link; Sunset Way; Upper Peirce Reservoir; Upper Thomson Nature Park.

Habitat/Ecology. This species is associated occasionally with primary forests, mostly with mature and/or old secondary habitats, and infrequently with young secondary forest fragments of varying levels of disturbance in Singapore. These include native-dominated secondary forest, abandoned plantation and waste woodland secondary forests. Individuals can be found foraging on leaf litter, dead wood, fallen logs, tree trunks or low foliage.

Remarks. This species has a wide range of variation in the development and shape of petiole, spines, and also pilosity. A critical revision is needed to clarify its status as a single species.