Cladomyrma hewitti

Cladomyrma hewitti
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Formicinae
Tribe:	Plagiolepidini
Genus:	Cladomyrma
Species:	C. hewitti
Binomial name
	Cladomyrma hewitti; (Wheeler, W.M., 1910) Specimen Label

All specimens of Cladomyrma hewitti, from just a few collections, are all from Sarawak and Brunei. Heterick & Kitching (2022) collected this species in a flight intercept trap within a lowland dipterocarp forest in Brunei.

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 hewitti belongs to the raised petiole group.

After examining the type again and remounting the queen, it became obvious that the extremely long head of the worker is correlated with a unique, long, parallel-sided head of the queen, and a nodiform petiole, which is not present in andrei or indeed any other species. In lateral view the queen head of the lectotype specimen is rather elongated, correlated with an exceptionally long alitrunk. In these respects the type thus differs from all other Cladomyrma species. None of the additional specimens has this elongated head or AL size. However, in the nontype specimens the character combinations of a long head, together with the raised petiole, make it most likely that they belong to the same species.

Keys including this Species

Key to Cladomyrma

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo (type locality), Brunei Darussalam, Indonesia, Malaysia.

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Agosti et al. (1999) - The type specimen was collected in Bidi (SW of Kuching, near Bau), Sarawak, in the "swollen internodes of a shrub" (label information). Based on current knowledge, the shrub might be a representative of one of eight domatia-bearing Bornean Neonauclea species, the only host tree genus of Cladomyrma with distinct swollen internodes whose species locally grow as shrubs (the other Bornean hosts are either understory treelets or climbers). Indeed, new collections of this species were made only from domatia of two Neonauclea species. However, it cannot be excluded that the ‘‘shrub’’ may belong to Myrmeconauclea strigosa, a small rheophytic treelet or shrub with spontaneously opening domatia. This species, regularly colonized by a variety of facultative stem-nesting ant species (Maschwitz et al., 1989), was never found to be inhabited by Cladomyrma in Sabah and Sarawak (n > 50), but recent collections in Brunei revealed that colony-founding queens rarely colonize the domatia of Myrmeconauclea strigosa (C. Brouat and D. McKey, personal commun.). It is not known if neighboring Neonauclea trees, which often grow in Myrmeconauclea habitat, are the source plants of these foundress queens. A second trip to the collecting site revealed that Neonauclea, inhabited by Cladomyrma ants, grow in close vicinity to Myrmeconauclea strigosa (D. McKey, personal commun.). We suspect that only a very low frequency of Cladomyrma queens occupy the latter plant species, presumably due to high intraspecific competition for regular host plants in the vicinity. Mature colonies or alates of Cladomyrma were not found in Myrmeconauclea strigosa. Nevertheless, this phenomenon needs to be studied in detail.

Castes

Wheeler 1910. Figure 1.

Worker

Images from AntWeb


Worker. Specimen code casent0173907. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by CAS, San Francisco, CA, USA.

Queen

Images from AntWeb


Queen (alate/dealate). Specimen code casent0173908. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by CAS, San Francisco, CA, USA.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

hewitti. Aphomomyrmex hewitti Wheeler, W.M. 1910c: 132, fig. 1 (s.w.q.) BORNEO (East Malaysia: Sarawak).
- Type-material: lectotype major worker (by designation of Agosti, 1991: 303); 7 paralectotype major and minor workers, 2 paralectotype queens.
- Type-locality: lectotype Malaysia: Borneo, Sarawak, Bidi, viii.1907 (J. Hewitt); paralectotypes with same data.
- Type-depository: MCZC.
- Combination in Cladomyrma: Wheeler, W.M. 1920: 53. Agosti, et al. 1999: 20 (w.).
- Junior synonym of andrei: Agosti, 1991: 303; Bolton, 1995b: 145.
- Status as species: Wheeler, W.M. 1919e: 102; Emery, 1925b: 45; Chapman & Capco, 1951: 208; Agosti, et al. 1999: 20 (redescription); Pfeiffer, et al. 2011: 39.
- Distribution: Malaysia (Sabah, Sarawak).

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Worker maxima. Length 3-3.5 mm.

Head flat, nearly as convex below as above, subrectangular, longer than broad, with straight subparallel sides, rounded posterior and blunt anterior corners. Eyes small, elliptical, flat, placed near the middle of the sides of the head and not on its upper surface. Ocelli present in some specimens but very small. Clypeus large, feebly convex behind, depressed in front, its anterior border rounded in the middle, not projecting, its posterior border not projecting back between the frontal carinae to any appreciable extent. Frontal carinm very small and short, the distance between them little more than half the distance between each of them and the corresponding lateral border of the head. Frontal area obsolete, frontal groove tenuous, but distinct. Mandibles small, with parallel internal and external borders and four sub-equal teeth; outer border with a blunt tooth near the base. Antennae 8-jointed, short; scapes rather slender, straight, reaching only a short distance behind the eyes; first funicular joint slende’r, twice as long as broad, remaining joints slightly enlarged towards the tip of the antenna; joints

2-6 as broad as long, terminal joint shorter than the three preceding joints together. Thorax thickset, depressed, as long but not as broad as the head, broader in front than behind. Promesonotal and mesopinotal sutures distinct; mesonotum somewhat higher than the pronotum, feebly convex, forming a regular transverse ellipse. Mesopinotal constriction short but distinct, its bottom formed by the mesopinotal suture only. Epinotum a little broader than long, with feebly rounded sides, its base very short and horizontal, passing through a rounded angle into the much longer, sloping and flattened declivity. Petiole somewhat lower than the epinotum and only about one-third as broad, as long as high and wide, with an erect, transverse node, which has fiat anterior and posterior surfaces and a rounded

upper surface. Gaster very broadly elliptical, smaller than the head, flattened dorsoventrally, with well-developed anal cilia. Legs long and robust; fore femora somewhat incrassated; claws and empodia large.

Body shining. Mandibles, elypeus and cheeks subopaque, punetate and finely striate, except the middle of the elypeus, which is opaque and coarsely punetate. Head sparsely, thorax and gaster more densely punetate and less glabrous.

Hairs yellowish, rather long and abundant, erect or suberect on all parts of the body and appendages, including the antennal funiculi. Pubescence yellowish, sparse and rather long, distinct on the thorax and gaster only in certain lights.

Dark brown or black; mandibles, cheeks and clypeus deep red; articulations of legs and thorax, antennal funiculi and tarsi more yellowish.

Worker media. Length 2.8 mm.

Closely resembling the worker maxima, but the head is somewhat smaller and distinctly narrowed anteriorly, and the clypeus and cheeks are less deeply punctate and striate and therefore more shining. Ocelli absent. Antennal scapes reaching about halfway between the eyes and the posterior corners of the head. Tooth on the external border of the mandibles obsolescent.

Worker minima. Length 2 mm.

Resembling the worker media, but the head is smaller, only a little longer than broad, as broad in front as behind, with feebly rounded sides, straight posterior border and rounded posterior corners. Ocelli absent. Clypeus convex and shining, its sides and the cheeks scarcely striate. Mandibles small, without a tooth on their external borders. Joints 2-6 of the antennal funiculi a little broader than long; scapes reaching half way between the eyes and the posterior corners of the head. Thorax not constricted in the mesopinotal region above. Gaster as large as the head. Mandibles, clypeus, antenn0e and petiole yellowish like the articulations of the legs and thorax.

Agosti et al. (1999) - Major: AL 0.98–1.23, HL 0.95–1.26, HW 0.84–1.06, EL 0.16–0.23, SL 0.44–0.52, CI 86–90, EI 19–23, SI 47–55 (n = 8).

Elongate head with subparallel sides; clypeus, in lateral view, rounded; large metapleural gland orifice; body dark brown with gaster and head distinctly darker; genae lighter brown; body surface shining; gastral pubescence sparse, widely set, so that pubescence hairs do not overlap; medium to large sized ants.

Minor worker. AL 0.70–0.90, HL 0.66–0.84, HW 0.58–0.74, EL 0.13–0.18, SL 0.32–0.45, CI 87–88, EI 22–25, SI 55–61 (n = 4).

Body color dark brown with gaster and head darker; metapleural gland orifice large; medium sized ant; gastral pubescence on tergites widely set and short; hairs not longer than the space in-between them.

Queen

Female. Length 6-7 rnm.

Body long and narrow. Head like that of the worker maxima but larger and with much larger eyes and well-developed ocelli. Clypeus very fiat, Antennm 8-jointed; scapes reaching about one-third the distance from the eyes to the posterior corners of the head. Second funicular joint as long as the first, which is fully twice as long as broad; joints 3-6 subequal, fully as long as broad and not increasing in width distally, terminal joint shorter than the two preceding joints together. Thorax as broad as the head, but twice as long, from above regularly elongate-elliptical, dorsally depressed, evenly and feebly rounded. Sides of neck much swollen and projecting anteriorly. Mesonotum and scutellum each somewhat broader than long; epinotum very feebly rounded above, uniformly sloping, without distinct base and declivity. Petiole nearly as high as the epinotum, as long as high and broad, its node thick and cuboidal in profile, seen from above transversely elliptical. Gaster elongate elliptical, nearly as large as the thorax. Legs long and stout, with large claws and empodia. Wings moderately long (6 mm); venation as in Plagiolepis.

Sculpture and pilosity like those of the worker maxima.

Black; mandibles (except the teeth), clypeus, antennm, tarsi, metanotum, anterior border of scutellum, articulations of the thorax, wings and legs, red; wings uniformly infuscated, with brown veins and blackish stigma.

Agosti et al. (1999) - AL 2.32–2.92, HL 1.60–1.80, HW 1.32–1.36, EL 0.52–0.60, SL 0.80–0.92, CI 77–83, EI 37–45, SI 60–68 (n = 6). Lectotype: Soldier(?) AL 1.18, HL 1.22, HW 1.06, SL 0.50, EL 0.22, CI 87, EI 21, SI 47. Queen from same series as lectotype: AL 2.92, HL 1.8, HW 1.32, EL 0.60, SL 0.84, CI 73, EI 45, SI 54.

Clypeus slightly angulate with anterior face straight; head long in full frontal view, with parallel sides; genae same color as reminder of head; dorsal part of katepisternum punctulate and with thin pubescence; metapleural gland orifice large and open; petiole in lateral view high, dorsally truncated with the posterior face gently sloped; whole body covered with long, erect hairs; gaster with short, widely set subdecumbent pubescence; gaster surface with silky shine; head and alitrunk (dark) brown, gaster with at least posterior parts of tergites darker; large body size.

Type Material

Described from two females, six maxima workers, one media and one minina, taken by Mr. John Hewitt at Bidi, Borneo, during August, 1907, "in the swollen internode of a shrub."

Wheeler did not state where these types were deposited.

References

References based on Global Ant Biodiversity Informatics

Agosti D., J. Moog, and U. Maschwitz. 1999. Revision of the Oriental Plant-ant genus Cladomyrma. American Museum Novitates 3283: 1-24.
Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
Wheeler W. M. 1910. A new species of Aphomomyrmex from Borneo. Psyche (Cambridge) 17: 131-135.
Wheeler W. M. 1919. The ants of Borneo. Bulletin of the Museum of Comparative Zoology 63:43-147.