Calyptomyrmex loweryi

Calyptomyrmex loweryi is fairly widespread, being known from sites across northern Borneo as well as the Philippines. Biologically, it has been encountered in a rubber plantation, a reafforestation area and in rainforest, and were found in a rotten log, under a large log and in leaf litter samples.

Identification
Hairs on head and body spatulate (noticeably narrower near the body and expanded distally and with a rounded tip) and appressed closely to the underlying body surface, gaster finely and indistinctly sculptured, moderately shiny to moderately dull, propodeum unarmed, posterior margin of head flatter, its lateral corners more sharply rounded. This species is most similar to Calyptomyrmex beccarii but differs in having the head broader and more angular above the level of the antennal scrobe and in being larger (head width > 1.13mm).

Distribution
This taxon was described from Philippines (Bukidnon).

Nomenclature
Types. Holotype worker, 108 worker paratypes and numerous larvae from 2km N Malaybalay, Bukidnon, Philippines, 13 September 1978, B. B. Lowery, reafforestation area, in rotten log (holotype in, ANIC32-053401, paratypes ANIC32-051639 (102 in , 3 in , 3 in )). Paratypes: 2 workers, same data as holotype except ANIC32-051640; 112 workers and numerous larvae from 7km S Malaybalay, Bukidnon, Philippines, 8 September 1978, B. B. Lowery, rubber plantation, under large log (, ANIC32-051641).

Taylor (1991) noted that the specimens from Malaybalay here placed in loweryi, together with others from Sarawak (which are here treated as belonging to beccarii), were similar to beccarii and might belong to that species or possibly to glabratus (which he speculated might actually be a synonym of beccarii, a treatment confirmed here). In fact, these Philippine specimens belong to a separate species (loweryi). Calyptomyrmex loweryi can be separated from beccarii as follows: (1) spatulate hairs broader than those found in beccarii, and less dense, especially on gaster; (2) posterior margin of head flatter and with the lateral corners more sharply rounded; (3) dorsal face of propodeum finely matte, lacking the low rugae found in beccarii; and (4) body larger (HW > 1.13mm vs. HW < 1.10mm, ML > 1.04mm vs. ML < 1.03mm). Combined, these characters separate this species from close relatives.

Description
Worker description. Mandibles indistinctly striate, more strongly basally, less so apically. Eyes with 5–7 ommatidia in greatest diameter. Propodeum in lateral view lacking angles or spines. Propodeal lobes thin anteriorly, thickened posteriorly. Node of petiole in profile slightly higher and larger than that of postpetiole. In dorsal view the petiolar and postpetiolar nodes approximately the same width. Head, promesonotum and petiolar and postpetiolar nodes rugose, the rugae enclosing foveolate spaces, the spaces smallest on the head and larger on mesosoma and nodes. Sides of mesosoma irregularly rugose, more strongly on pronotum, weakly so on propodeum. Spaces between rugulae indistinctly shagreened or finely reticulate-punctulate, matt and dull. Dorsum of propodeum very finely sculptured and with a matte surface, a few very fine rugae sometimes present. Gaster finely and indistinctly sculptured, moderately shiny to moderately dull. Hairs on head and body spatulate and appressed. Clypeal fork with spatulate hairs only. Colour dull red-brown.

Measurements. Worker (n = 5) - CFW 0.21–0.24; CI 104–108; HL 1.07–1.16; HW 1.15–1.25; ML 1.05–1.14; MTL 0.54–0.59; PetI 133–143; PetL 0.28–0.32; PetW 0.39–0.44; PronW 0.75–0.82; SI 48–51; SL 0.58–0.64.