Calyptomyrmex beccarii Emery

Shattuck, Steven O., 2011, Revision of the ant genus Calyptomyrmex (Hymenoptera: Formicidae) in South-east Asia and Oceania, Zootaxa 2743, pp. 1-26 : 5-7

Calyptomyrmex beccarii Emery

( Figs 3 , 18 )

Calyptomyrmex beccarii Emery, 1887: 472 .

Calyptomyrmex beccarii glabratus Viehmeyer, 1916: 128 (raised to species by Baroni Urbani, 1975: 410). New synonym. Calyptomyrmex emeryi Forel, 1901: 51 (queen described by Wheeler, 1919: 90). New synonym. Calyptomyrmex schraderi Forel, 1901: 50 (neotype designation and junior synonym of C. beccarii by Taylor, 1991: 600). Weberidris rufobrunnea Donisthorpe, 1949a: 281 (combination in Calyptomyrmex by Donisthorpe, 1949b: 186 and Brown,

1949: 84; junior synonym of C. beccarii by Brown, 1951: 101).

Types. C. beccarii : Worker (apparently a single specimen, therefore holotype) from Ambon (as Amboina), Indonesia (MSNG, not examined). C. beccarii glabratus: Two worker syntypes from Singapore (MNHB, images from www.anttypes.org examined). C. emeryi: Three worker and one male syntype from Sarawak, Malaysia (MHNG, examined). C. schraderi : Neotype worker from Iron Range, Queensland, ANIC32-047446, designated by Taylor (1991) (ANIC, examined). W. rufobrunnea : Holotype worker from Maffin (as Maffin Bay), Papua, Indonesia (BMNH, not examined, specimens from type nest series present in MCZC, examined).

Diagnosis. 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, propodeum unarmed, posterior margin of head more rounded, especially its lateral corners. This species is most similar to loweryi but differs in having the head narrower above the level of the antennal scrobe and in being smaller (HW <1.10mm rather than greater than 1.13mm).

Worker description. Mandibles delicately striate (sometimes weakly so). Eyes with 5–6 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 node slightly narrower than the postpetiolar node. Head, promesonotum, dorsal and posterior faces of propodeum and petiolar and postpetiolar nodes rugose, the rugae enclosing foveolate spaces, this sculpturing most strongly developed on the front of the head, weaker and less defined posteriorly. 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. Gaster finely and indistinctly sculptured. Hairs on head and body spatulate and appressed. Clypeal fork with spatulate hairs only. Colour dull red-brown.

Measurements. Worker (n = 11) - CFW 0.19–0.22; CI 97–105; HL 0.95–1.06; HW 0.93–1.09; ML 0.91–1.02; MTL 0.43–0.53; PetI 123–148; PetL 0.22–0.28; PetW 0.29–0.39; PronW 0.60–0.74; SI 50–54; SL 0.49–0.57.

Additional material examined (in ANIC except where noted). Australia: Queensland: 18.5km W St. Lawrence (Cook & Monteith) ( QMBA); Boombana Nat. Park, Site 1 (QM Party) ( QMBA); Iron Range (Taylor,R.W. & Feehan,J.) ( ANIC, QMBA, TERC); Lockerbie, Cape York (Monteith,G.B.); Mt Jacob, c. 45mi. S Gladstone (Darlingtons) ( MCZC). East Timor: Salele, 23km W Suai, Suai Kabupaten (Agosti,D.). Indonesia: Papua: Maffin Bay (Ross,E.S.) ( MCZC); Central Sulawesi: Polit Kecil, Banggai Arch. (Brendell,M.J.D.) ( BMNH). Malaysia: Sarawak: Kampong Segu, 20mi. SW Kuching (Taylor,R.W.). Palau Islands: Koror Island (Dybas,H.S.) ( MCZC). Papua New Guinea: Central: 5–6km N Brown River, C.P. (Brown,W.L.) ( MCZC); Karema, Brown River (Wislon,E.O.) ( MCZC); East Sepik: Yawasora (collector unknown); Morobe: Lae (Woodward,T.E.); Mt. Mission, Wau (Cuccodoro,G.) ( BMNH); Northern: Lejo (Room,P.M.); Popondetta (Room,P.M.); Togao Rd. (Room,P.M.). Philippines: Camarines Sur: Panicuason Village, 18km E Naga City (General,D. & Alpert,G.) ( MCZC); Luzon: Mt. Makiling, Lagunas (Löbl,I.) ( BMNH); Negros Oriental: Camp, Dumaguete (Chapman,J.W.) ( MCZC). Singapore ( MNHB).

Comments. This is by far the most widespread species examined in this study, occurring from Singapore north-east to the Philippines and south to Papua New Guinea and northern Australia. And although it is not particularly morphologically variable, it has been described no fewer than five times. For example, Taylor (1991) recognised that schraderi was conspecific with beccarii and also speculated that glabrata might be a junior synomym as well, although he did not study this last problem in detail and left the taxonomic status of these taxa unchanged. These proposals, as well as the synonymy of emeryi , are supported in this study.

Taylor’s (1991) synonymy of the Australian-based schraderi with beccarii is supported here. However, it should be noted that the Australian populations do show slight differences when compared to more northern populations. Specifically, the spatulate hairs on the head and mesosoma of northern populations are narrower and more slender compared to the broader and more rounded hairs found in Australian specimens. However, hairs on the gaster are essentially identical and no further differences were found. Thus the available evidence suggests that these differences are little more than population-based geographic variation.

Comparable differences are also present in the single specimen of this taxon from East Timor. While very similar to other specimens examined during this study, this specimen differs in having the spatulate hairs on the head and mesosoma more erect and raised distinctly above the surface of the body. In specimens from other regions these hairs are at most only slightly raised above the surface. As with Australian specimens, no other differences were detected and this specimen is here considered to belong to beccarii .

The types of glabratus, the western-most samples known for this species, show only slight differences from other specimens here placed in this taxon. These differences include the petiolar node in lateral view being slightly higher and more angular and the pronotal corners in dorsal view being more angular compared to specimens from further east. However, these differences are slight and are not unexpected for such a wide-spread species. Because no additional differences could be found glabratus is here considered to be a junior synonym of beccarii . This confirms the suspicions of Taylor (1991).

Finally, an examination of the holotype of emeryi shows this taxon conforms to the concept of beccarii developed here and is a straightforward synonym. Forel (1901) provided a very brief description and failed to note any differences between this species and either beccarii or schraderi (which he described in the same paper as emeryi ). None could be found during this study and therefore this name is treated as conspecific with beccarii .

As with most other species within this genus, beccarii is found in rainforest and is most often encountered in leaf litter samples, although one nest was found in a carton termite nest.

Figures

FIGURE 3. Calyptomyrmex beccarii (Iron Range, Queensland, ANIC 32 - 047446): A. Front of head; B. Side of body; C. Top of body; D. Distribution of material examined.

FIGURE 18. Head length versus head width for C. asper, C. beccarii, C. danum, C. fritillus, C. loweryi, C. ryderae, C. sparsus and C. taylori.