Cataulacus marginatus

Identification
Extremely closely related to Cataulacus granulatus; separable from that species only by the possession of a very strongly marginate first gastral tergite. As Cataulacus granulatus itself occurs on Hainan Is. there is a possibility that marginatus is only a local population of that species and further collecting may show the two forms to be intergradient. It should be stressed that the gastral margination of the new species is very strongly developed and is visible to the naked eye, and this character serves easily to distinguish the two.

Distribution
This taxon was described from China.

Nomenclature

 *  marginatus. Cataulacus marginatus Bolton, 1974a: 68, fig. 38 (w.) CHINA.

Worker
Holotype. TL 5.3, HL 1.24, HW 1.38, CI 111, EL 0.44, OI 32, IOD 1.08, SL 0.62, SI 45, PW 1.20, AL 1.42, MTL 0.70.

Occipital crest concave, the lateral portions better developed than the median which is represented only by a row of denticles. Lateral portions of the crest denticulate, as are the sides of the head behind the eyes. Occipital corners with a small, triangular tooth. Sides of frontal carinae irregular, especially on the posterior half, but their overall outline in full-face view is very weakly convex, and convergent anteriorly. Margins of pronotum, mesonotum and propodeum strongly denticulate, with a few denticles upon the outer margins of the propodeal spines. A small gap is present separating the denticles of the pro- and mesonotum and a larger, more obvious impression or notch occurs between mesonotum and propodeum. Propodeal spines with their bases widely separated, the spines themselves narrow, acute and each one shorter than half the basal distance separating it from its twin. Petiole in dorsal view massive, notably more so than the postpetiole, both segments broader than long. In profile the anterior, dorsal and posterior surfaces of the petiole form a more or less continuous convexity. Subpetiolar process simple, truncated basally. Sides of first gastral tergite very strongly marginate, the margins prominent.

Head reticulate-rugose, the interspaces shallowly reticulate-punctate and dully shining. Dorsum of alitrunk similarly sculptured, the points of intersection of the rugae raised into minute tubercles. Declivity of propodeum transversely rugose. Sculpturation of pedicel as alitrunk but coarser, first gastral tergite very finely reticulate-rugose with reticulate-punctate interspaces. Dorsal surfaces and lateral margins of head, body and appendages with numerous short, thick, blunt whitish hairs.

Paratype. TL 4.8 – 6.0, HL 1.16 – 1.32, HW 1.30 – 1.50, CI 112 - 114, EL 0.42 – 0.46, or 31 - 32, IOD 1.02 – 1.14, SL 0.60 – 0.66, SI 43 - 46, PW 1.10 – 1.30, AL 1.28 – 1.56, MTL 0.68 – 0.76 (9 measured).

As holotype but the sculpturation of the alitrunk somewhat variable. The rugae may tend to take on an apparently longitudinal direction due to the emphasis being placed on those rugae. The cross-meshes are reduced but not lost. In some the components of the rugoreticulum are rather more broad, flattened and less sharply defined than in others.

Type Material
Holotype worker, CHINA: Hainan Is., grove near Hoi Man Chuen, S.W. of Nodoa, 4.vii.1929, Lingnan University 5th Hainan Is. expedition, 1929.

Paratypes. 4 workers, CHINA: Hainan Is., Ta Hau, 7.vii.1935 (J. L. Gressit). 1 worker, same data as above but 4-5.vii.1935 (MCZ). 4 workers, CHINA: Hainan Is., Nodoa, 15-17.vii.1935 (J. L. Gressitt) (MCZ).

Additional References

 * [[Media:Bolton 1974a.pdf|Bolton, B. 1974a. A revision of the Palaeotropical arboreal ant genus Cataulacus F. Smith (Hymenoptera: Formicidae). Bull. Br. Mus. (Nat. Hist.) Entomol. 30: 1-105 PDF]]