Calyptomyrmex sparsus

This rare species is known from a single collection of two workers encountered while pyrethrum fogging rainforest logs and trees in Far North Queensland.

Identification
Hairs on head and body spatulate (noticeably narrower near the body and expanded distally and with a rounded tip), gaster weakly punctate (fading posteriorly), propodeum armed with low, angular spines, in dorsal view petiole only slightly broader than long and oval in shape, body larger (HW > 1.12) and head longer than broad (CI < 98).

This species is similar to Calyptomyrmex fritillus but differs in having a larger body (head width > 1.12mm) and in dorsal view the petiole is only slightly broader than long and is oval in shape (in fritillus the body is smaller (head width < 0.82mm) and in dorsal view the petiole is much broader than long and rectangular in shape). It differs from the very similar Calyptomyrmex danum in being larger (head witdth > 1.12mm vs. head width < 1.12mm) and having the head longer than broad (CI < 98 vs. CI > 104 in danum). For additional differences see Calyptomyrmex danum.

Identification Keys including this Taxon
Key to Australian Calyptomyrmex Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  sparsus. Calyptomyrmex sparsus Shattuck, 2011: 22, figs. 16, 18 (w.) AUSTRALIA.

Description
Worker description. Mandibles indistinctly striate. Eyes with 5–6 ommatidia in greatest diameter. Propodeum in lateral view with low, angular spines. Propodeal lobes uniform in thickness. 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 with longitudinal, slightly wavy rugae which diverge and fade posteriorly and are superimposed over a punctate background. Promesonotum indistinctly foveolate, sides of mesosoma indistinctly rugose, entire mesosoma with a punctate background. Petiole, postpetiole and gaster punctate, the strength of the sculpture on the gaster fading slightly posteriorly. Hairs on head and body spatulate and appressed. Clypeal fork with spatulate hairs only. Colour dark red-brown, the legs and gaster slightly lighter.

Measurements. Worker (n = 2) - CFW 0.25–0.27; CI 95–96; HL 1.20–1.21; HW 1.14–1.16; ML 1.25–1.26; MTL 0.65–0.66; PetI 127–143; PetL 0.26–0.28; PetW 0.35–0.37; PronW 0.78–0.78; SI 55–62; SL 0.64–0.71.