Cladomyrma maschwitzi

Cladomyrma maschwitzi is the most widespread Cladomyrma species, occurring in Borneo, Peninsular Malaysia and in Sumatra.

Identification
Agosti et al. (1999) placed Cladomyrma species into two groups based on the shape of the queen's petiole, raised (an erect node or scale) or depressed (dorsally truncate and low). Cladomyrma maschwitzi belongs to the depressed petiole group.

This species is easily recognized by its small, light yellow workers, the large metapleural gland orifice, and the uniform brown-colored queen with, at most, appendages and frontal part yellowish. The Sumatran specimens differ somewhat in the body coloration of the queens, which is of a dark brown color and they are larger (AL = 2.24–2.38), however, the workers are of the same yellowish appearance as the non-Sumatran specimens.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia.

Biology
Agosti et al. (1999) - This species is known only from Crypteronia griffithii (Crypteroniaceae) but may inhabit another Crypteronia species as well. A detailed account of the protective function of C. maschwitzi to its host and colonization rates of different aged host trees are given in Moog et al. (1998). The ants patrol young foliage and deter or kill herbivores they encounter. In addition they clean the surface of young leaves from insect eggs. Preliminary data suggest a competitive relationship of C. maschwitzi with C. crypteroniae, the sympatric second ant partner of Crypteronia in Borneo and Sumatra (unpubl. results). It appears that young Crypteronia saplings are occupied primarily by maschwitzi, due to the smaller twig diameter, giving the smaller maschwitzi queens priority of access to the host plant resource. However, a large percentage of older saplings has been subsequently colonized by crypteroniae. It will be interesting to study this phenomenon in detail, i.e. if the observed pattern is the consequence of direct or indirect (e.g. better performance of initial colonies) interactions between the two species. An alternative hypothesis— that the host plant is locally so abundant that founding queens do not compete for it—can be excluded both by a colonization rate of almost 100% and by the regular occurrence of multiple founding on individual host plants.

Moog et al. (1997) - Cladomyrma maschwitzi, like all Cladomyrma species, are arboreal ants. This species nests in excavated tree branches of Crypteronia griffithii. The tropical forests where their host occurs experience frequent and strong rains. The risk of rain and rain-runoff getting into C. maschwitzi nests is mitigated in part by their laterally oriented nest-entrances. If water does get into a nest, it is removed using a water-bailing behavior. Workers will ingest the liquid and regurgitate it outside the nest until no standing water remains.

Nomenclature

 *  maschwitzi. Cladomyrma maschwitzi Agosti, 1991: 306, figs. 5, 8-12, 15, 19, 21, 24 (s.w.q.m.) WEST MALAYSIA. See also: Agosti, Moog & Maschwitz, 1999: 11.

Description
Agosti et al. (1999):

Worker
Major worker. AL 0.84–1.00, HL 0.81–0.98, HW 0.68–0.82, EL 0.15–0.20, SL 0.38–0.48, CI 83–85, EI 22–25, SI 53–59 (n = 8).

Median part of clypeus coarsely sculptured; large, open metapleural gland orifice; whole body light yellow colored; few hairs on dorsum of mesonotum.

Minor worker. AL 0.68–0.71, HL 0.62–0.65, HW 0.52–0.56, EL 0.12–0.14, SL 0.32–0.34, CI 84–87, EI 22–25, SI 57–63 (n = 8).

Large, open metapleural gland orifice; whole body light yellow colored.

Queen
AL 1.82–2.38, HL 1.22–1.41, HW 0.98–1.06, EL 0.44–0.48, SL 0.62–0.68, CI 74–80, EI 44–49, SI 63–66 (n = 6). Holotype: AL 1.82, HL 1.62, HW 0.92, SL 0.62, EL 0.44, CI 80.3, EI 55, SI 63.

Dense, subdecumbent pubescence on scape, occiput, and alitrunk; an- and katepisternum with few erect hairs, especially in the dorsal regions; large metapleural gland orifice; petiole low, dorsally truncated but slightly dorsally convex.

Type Material
Agosti et al. (1999) - Holotype queen, WEST MALAYSIA, Selangor, Ulu Gombak, 1990, #3, ex Crypteronia griffithii, Joachim Moog,.