Myrmicaria adpressipilosa Santschi, 1928 stat. n.

Myrmicaria (Heptacondylus) arachnoidea [sic] var. adpressipilosa Santschi, 1928: 130 (w.)

Subspecies of Myrmicaria arachnoides: Bolton, 1995: 285; Pfeiffer et al., 2011: 16.

Material examined. Queen and workers, Nee Soon forest, 11 Feb 1974, D.H. Murphy leg., ZRC _ ENT00006313 .

Material not physically examined. Unknown.

Literature. None. New record.

Localities. Nee Soon forest

Habitat/Ecology. This species was found in swamp forest and/or its adjacent drier native-dominated secondary forest, also in old or mature secondary forest further inland. The ants build carton nests on leaves and foliage, usually on undersides of large tree leaves.

Remarks. Myrmicaria adpressipilosa was originally described as a subspecies of Myrmicaria arachnoides (Smith, 1857) . Emery (1900) stated that M. adpressipilosa resembled Myrmicaria arachnoides lutea Emery, 1900 in terms of body colour and general habitus, but could be differentiated from the latter, by the mostly adpressed or decumbent hairs on its body. Based on colonies of both taxa from other parts of Southeast Asia, it was later determined that the adpressed hairs are really an artifact and not diagnostic of the species (Bakhtiar & Yamane 2022, unpublished) Further examination of those colonies revealed more compelling differences between workers of both species (Bakhtiar & Yamane 2022, unpublished). Myrmicaria adpressipilosa can be distinguished from M. arachnoides based on the following ( M. arachnoides traits in parentheses): 1) propodeal spiracle large, its maximum diameter slightly shorter or longer than distance between spiracle and dorsal margin of propodeum (propodeal spiracle small, its maximum diameter much shorter than distance between spiracle and dorsal margin of propodeum), 2) pronotal and propodeal sides irregularly striate (pronotal and propodeal sides extensively smooth and shining), 3) propodeal declivity with lateral longitudinal carinae (propodeal declivity lacking lateral carinae) [Bakhtiar & Yamane 2022, unpublished].