Strumigenys luca

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

A well collected Strumigenys species that has been found in a wide range of forest habitats. Specimens have been found in litter, on the ground and in rotting wood.

Identification

Bolton (2000) - A member of the hilaris complex in the Strumigenys arnoldi-group. S. luca is most similar to Strumigenys milae in the hilaris-complex and can be easily distinguished from the latter species by the presence of a single pair of erect hairs on the mesonotum. See milae for further discussion.

Keys including this Species

Key to Malagasy Strumigenys

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -18.0264° to -18.0264°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (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

Worker

Images from AntWeb


Paratype of Strumigenys luca. Worker. Specimen code casent0005582. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by CAS, San Francisco, CA, USA.


Paratype of Strumigenys luca. Worker. Specimen code casent0005583. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by CAS, San Francisco, CA, USA.


Holotype of Strumigenys luca. Worker. Specimen code casent0005584. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by MCZ, Cambridge, MA, USA.

Nomenclature

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

luca. Strumigenys luca Fisher, in Bolton, 2000: 663 (w.) MADAGASCAR.

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 3.1, HL 0.69, HW 0.59, CI 85, ML 0.37, MI 53, SL 0.46, SI 78, PW 0.33, AL 0.74. Characters of hilaris-complex. Each mandible with 2 preapical teeth, situated in the apical third; proximal preapical tooth longer than distal. Upper scrobe margin distinct but not bordered by a projecting laminar rim or flange throughout its length. Eyes moderate in size, convex, and plainly visible in full-face view; maximum diameter of eye distinctly greater than maximum width of scape. Scape short, more or less straight, widest in the mid section; hairs on leading edge fine, slightly flattened or spoon-shaped apically. Cephalic dorsum densely clothed with curved narrowly spatulate to flattened spatulate ground-pilosity; upper scrobe margin fringed with curved narrowly spatulate hairs. Cephalic dorsum with 4 stout standing hairs arranged in a transverse row close to the occipital margin and a more anteriorly situated pair on vertex. Pronotal humeral hair absent; humeral angles rounded, posterior lateral margin of pronotum bluntly marginate. Anterior margin of mesonotum with a pair of stout filiform hairs. Propodeum with one pair of short, fine, posteriorly curved hairs at anterior base of propodeal spines. Ground-pilosity on alitrunk as on head but sparser. Dorsum of alitrunk in outline convex anteriorly, posterior mesonotum gradually sloping down to metanotal groove. Anterior propodeum slightly raised above mesonotum; propodeum not flat, gradually sloping down to declivity. Propodeal spines narrowly triangular, subtended by a narrow lamella on declivity. Alitrunk dorsum and side of pronotum densely reticulate-punctate, portions of central pleurae often smooth and shiny. Petiole node in dorsal view about as broad as long. Postpetiole disc densely and finely reticulate-punctulate. Spongiform appendages of petiole absent; weakly developed on postpetiole. Spongiform collar present only on posterior margin of postpetiole. Basigastral costulae short and distinct, with secondary and much longer fine striolate sculpture arising between the shorter costulae. Dorsal surfaces of petiole, postpetiole and gaster with stout standing narrowly remiform hairs. Colour light to medium brown.

Paratypes. TL 2.8-3.1, HL 0.63-0.70, HW 0.53-0.61, CI 83-91, ML 0.35-0.38, MI 52-58, SL 0.43-0.49, SI 75-84, PW 0.32-0.35, AL 0.68-0.74 (9 measured). As holotype.

Measurements of this material extend the range shown by the type-series: HL 0.63-0.73, HW 0.53-0.58, CI 79-85, ML 0.34-0.40, MI 52-59, SL 0.44-0.48, SI 82-85 (5 measured). This material shows variation in the outline of the posterior portion of the alitrunk. In some specimens, the anterior margin of the propodeum is not raised above the mesonotum, and the propodeum is more or less flat.

Type Material

Holotype worker, Madagascar: Provo Toliara, southern Isoky-Vohimena Forest, 59 km. NE Sakaraha, 22°41'S, 44°50'E, 730 m., 21.i.1996, sifted litter (leaf mold, rotten wood), tropical dry forest #1312 (4)-3 (S. Razajimandimby) (Museum of Comparative Zoology).

Paratypes. 16 workers with same data as holotype but coded (1)-4, (2)-1, (3)-2, (5)-2, (7)-4, (8)-3, (18)-3, (25)-1, (28)-1, (30)-4, (36)-2, (46)-2, (The Natural History Museum, South African Museum).

References

Fisher, B.L. 2000. The Malagasy fauna of Strumigenys. Pp. 612-696 in: Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 663, worker described)

References based on Global Ant Biodiversity Informatics

Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
Fisher B. L. 2003. Formicidae, ants. Pp. 811-819 in: Goodman, S. M.; Benstead, J. P. (eds.) 2003. The natural history of Madagascar. Chicago: University of Chicago Press, xxi + 1709 pp.
Ravelomanana A., and B. L. Fisher. 2013. Diversity of ants in burned and unburned grassland , and dry deciduous forest in the Beanka Reserve, Melaky Region, western Madagascar. Malagasy Nature 7: 171-183.