Strumigenys heteropha

Strumigenys heteropha
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Strumigenys
Species:	S. heteropha
Binomial name
	Strumigenys heteropha; Bolton, 2000 Specimen Labels

Tang et al. (2019) found this species in Hong Kong in several closed-canopy habitats including tree plantations of Lophostemon confertus Wilson & Waterh., secondary forests and Feng Shui woods with an elevation range from 106 to 367 m. Tang & Guenard (2023) report it in primary forest, secondary forest and rubber plantations.

Identification

Bolton (2000) - A member of the caniophanes complex in the Strumigenys caniophanes-group. One of four species in this group to lack preapical dentition, heteropha is separated from the other three (Strumigenys caniophanes, Strumigenys cygarix, Strumigenys dromica) by having the katepisternum smooth; in the others the side of the alitrunk is uniformly sculptured. Also heteropha lacks sulcate sculpture on the lateral alitrunk and lacks dense pubescence on the gaster and elsewhere. A related species, Strumigenys lacunosa, is known from Taiwan. Lin & Wu (1996) point out that the preapical dentition may be small in some samples of this species. It is probable that lacunosa will be found in China, or conversely that heteropha may be discovered in Taiwan. Disregarding the preapical dentition individuals of lacunosa can always be distinguished from heteropha as the former does not have punctate sculpture on the metapleuron and side of the propodeum and has propodeal teeth that are short, broad-based triangular in profile; in dorsal view the lateral spongiform lobes of the petiole in lacunosa extend as far forward as the anterior face of the node and the promesonotal dorsum does not have obvious rugulose sculpture.

Tang & Guenard (2023), Fig. 21. New species records of Strumigenys from Hainan, mainland China in full-face, profile and dorsal views. A–C. Worker of S. heteropha (HNA-01608). D–F. Worker of S. hexamera (HNA-01556). G–I. Worker of S. hirsuta (HNA-01573).

Keys including this Species

Key to Strumigenys of East Asia

Distribution

A widely-distributed species within Hong Kong, with its endemic status hypothesized to be the result of under-sampling in China rather than true endemism (Tang et al. 2019). This is now confirmed by its record in Hainan. Its presence in surrounding provinces of Guangdong and Guangxi in China can likely be confirmed through further sampling efforts. The record in in northern Vietnam further extends its native range westward, indicated that it has a much wider range than what was previously known. (Tang & Guenard, 2023)

Latitudinal Distribution Pattern

Latitudinal Range: 22.44348° to 19.1°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Oriental Region: Vietnam.
Palaearctic Region: China (type locality).

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

Explore Overview of Strumigenys biology

Strumigenys were once thought to be rare. The development and increased use of litter sampling methods has led to the discovery of a tremendous diversity of species. Many species are specialized predators (e.g. see Strumigenys membranifera and Strumigenys louisianae). Collembola (springtails) and other tiny soil arthropods are typically favored prey. Species with long linear mandibles employ trap-jaws to sieze their stalked prey (see Dacetine trap-jaws). Larvae feed directly on insect prey brought to them by workers. Trophallaxis is rarely practiced. Most species live in the soil, leaf litter, decaying wood or opportunistically move into inhabitable cavities on or under the soil. Colonies are small, typically less than 100 individuals but in some species many hundreds. Moist warm habitats and micro-habitats are preferred. A few better known tramp and otherwise widely ranging species tolerate drier conditions. Foraging is often in the leaf litter and humus. Workers of many species rarely venture above ground or into exposed, open areas. Individuals are typically small, slow moving and cryptic in coloration. When disturbed individuals freeze and remain motionless. Males are not known for a large majority of species.

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Castes

Nomenclature

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

heteropha. Strumigenys heteropha Bolton, 2000: 758 (w.) CHINA.

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

Description

Worker

Holotype. TL 3.2, HL 0.81, HW 0.62, CI 77, ML 0.40, MI 49, SL 0.44, SI 71, PW 0.36, AL 0.88. Mandible in full-face view without preapical dentition, though in oblique dorsolateral view a minute inconspicuous tumulus or cuticular prominence can be seen on the dorsal inner margin close to the apex. Dorsolateral margin of head in full-face view with 3 freely laterally projecting fine flagellate hairs: one just posterior to the level of the eye, one in apicoscrobal position and one close to the occipital corner. Cephalic dorsum with a pair of standing hairs at highest point of vertex and a transverse row across occipital margin. Dorsum of head finely densely reticulate-rugulose, the reticulae small and low, filled with dense reticulate-punctate sculpture. Dorsal alitrunk irregularly finely rugulose and punctulate. Katepisternum smooth, remainder of pleuron and side of propodeum finely punctate. Pronotal humeral hair long and flagellate. Dorsal alitrunk with fine erect sub flagellate to flagellate hairs and fine simple ground-pilosity. Waist segments and first gastral tergite with fine flagellate hairs. Dorsal and lateral surfaces of femora and tibiae with sparse erect flagellate hairs; ventral surface of femora with a few similar hairs and dorsal (outer) surfaces of middle and hind basitarsi with one or two much longer flagellate hairs. Propodeal teeth small and narrowly triangular. Petiole node in dorsal view longer than broad; disc of postpetiole scarcely broader than petiole node; both with dense reticulate-punctulate sculpture and a few superimposed small longitudinal rugulae. Lateral spongiform lobes of petiole in dorsal view terminate well posterior of the anterior slope of the node. Petiole in profile subclavate, node without an anterior face that is differentiated from the peduncle, instead the two forming a single uninterrupted surface.

Type Material

Holotype worker, China: Hong Kong, E Central New Territories, Shan Liu, 31.x.1996 (J. R. Fellowes) (The Natural History Museum).

References

Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 758, worker described)
Tang, K. L., Guénard, B. 2023. Further additions to the knowledge of Strumigenys (Formicidae: Myrmicinae) within South East Asia, with the descriptions of 20 new species. European Journal of Taxonomy 907, 1–144 (doi:10.5852/ejt.2023.907.2327).
Tang, K.L., Pierce, M.P., Guénard, B. 2019. Review of the genus Strumigenys (Hymenoptera, Formicidae, Myrmicinae) in Hong Kong with the description of three new species and the addition of five native and four introduced species records. ZooKeys 831: 1–48 (DOI 10.3897/zookeys.831.31515).

References based on Global Ant Biodiversity Informatics

Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
Fellowes J. R., M. W. N. Lau, D. Dudgeon, G. T. Reels, G. W. J. Ades, G. J. Carey, B. P. L. Chan, R. C. Kendrick, L. K. Shing, M. R. Leven, K. D. P. Wilson, and Y. Y. Tung. 2002. Wild animals to watch: terrestrial and freshwater fauna of concervation concern in Hong Kong. Memoirs of the Hong Kong Natural History Society 25: 123-160.
Tang K.L., Pierce M.P., and B. Guénard. 2019. Review of the genus Strumigenys (Hymenoptera, Formicidae, Myrmicinae) in Hong Kong with the description of three new species and the addition of five native and four introduced species records. ZooKeys 831: 1-48.