Crematogaster (Orthocrema) quadriruga Forel, 1911

Material examined. National University of Singapore campus (Clementi/Kent Ridge), Apr-Sep 2015, M.S. Foo & W. Wang leg., malaise trap, ZRC _BDP (multiple); Pulau Semakau Old Fragment, SMO2, 1°12’20.2”N, 103°45’35.8”E, 5-12 Jul 2012, J. Puniamoorthy et al. leg., mangroves, malaise trap, Reg. 29343, ZRC _ BDP0015230; Pulau Ubin, 7 Jan 2014, Sk. Yamane leg., ZRC _HYM_0000387- 388; Sungei Buloh Wetland Reserve, 14 Mar 2018, W. Wang leg., WW-SG18-Crem1, ZRC _ ENT00000905; Ulu Sembawang Road, 17 May 1994, collector unknown, NS 135, ZRC _ ENT00000269; Temasek Polytechnic, adjacent waste woodland, 1.34239, 103.93598, 15 Dec 2016, G.W. Yong leg., TT1TH548, ZRC _HYM_0001763 .

Material not physically examined. Unknown.

Literature. Wang et al. (2018a).

Localities. National University of Singapore campus (Clementi/Kent Ridge); Pulau Semakau Old Fragment; Pulau Ubin; Sungei Buloh Wetland Reserve; Ulu Sembawang Road; (beside) Temasek Polytechnic.

Habitat/Ecology. This species was often found in disturbed mature or young secondary forest fragments in urban or semi-urban settings, including waste woodlands, where the ants were found foraging on tree trunks. Crematogaster quadriruga has also been found in mangroves, where individuals have been collected from trails on elevated branches of living trees.

Remarks. This small, yellowish species is similar in appearance to C. bandarensis, but can be distinguished from the latter by its small propodeal spiracle that is located relatively apart from the metapleural gland bulla - in C. bandarensis the propodeal spiracle is large and touching the metapleural gland bulla.