Strumigenys hilaris

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

Known from rainforests, specimens have been collected from litter, a rotten log, and under a rock.

Identification

Bolton (2000) - A member of the hilaris complex in the Strumigenys arnoldi-group. S. hilaris, Strumigenys luca and Strumigenys milae constitute the hilaris-complex, characterized by 2 preapical teeth or denticles on the left mandible and the absence of a projecting pronotal humeral hair. Within this complex, hilaris can be identified by its relatively long scape, SI > 90.

Keys including this Species

Key to Malagasy Strumigenys

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -14.44528° to -14.44528°.


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 hilaris. Worker. Specimen code casent0005553. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by MCZ, Cambridge, MA, USA.

Queen

Images from AntWeb


Paratype of Strumigenys hilaris. Queen (alate/dealate). Specimen code casent0005554. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by MCZ, Cambridge, MA, USA.


Paratype of Strumigenys hilaris. Queen (alate/dealate). Specimen code casent0005555. 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.

hilaris. Strumigenys hilaris Fisher, in Bolton, 2000: 661, fig. 396 (w.q.) 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 0.75, HW 0.55, CI 74, ML 0.43, MI 57, SL 0.53, SI 96, PW 0.34, AL 0.77. Characters of hilaris-complex. Mandibles inserted close together and slightly diverging at full closure. Each mandible with 2 preapical teeth, situated in the apical third of the length; proximal preapical tooth longer than distal. Upper scrobe margin bordered by a narrow rim throughout its length. Eye small, convex, and plainly visible in full-face view; its maximum diameter more or less equal to maximum width of scape. Scape more or less straight, widest in the midsection; hairs on leading edge fine, slightly flattened or spoon-shaped apically. Cephalic dorsum densely clothed with curved to subappressed narrowly spatulate ground-pilosity; upper scrobe margin fringed with curved narrowly spatulate hairs. Cephalic dorsum with 4 simple 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. Anterior margin of mesonotum with a pair of stout filiform hairs. Propodeum with two pairs or occasionally one pair of short, fine, posteriorly curved hairs immediately anterior of propodeal spines or at base of propodeal spines. Ground-pilosity on alitrunk as on head but sparser. Dorsum of alitrunk in outline convex anteriorly, more or less flat posteriorly. Anterior mesonotum without a distinct carina above the mesothoracic spiracle. Propodeal spines narrowly triangular, strongly elevated; propodeal lamella absent. Alitrunk dorsum and sides of pronotum densely reticulate-punctate, pleurae smooth and shiny with peripheral punctures. Fine longitudinally striolate sculpture present on pronotal dorsum; rugulose sculpture present on posterior lateral margins of pronotum. Petiole node in dorsal view about as broad as long. Postpetiole disc densely and finely reticulate-punctulate with longitudinally striolate sculpture. In profile ventral spongiform tissue of petiolar peduncle a very narrow, irregular strip that is deepest in posterior third of petiole, the deepest point of the tissue less than maximum width of eye. Ventral spongiform lobe of postpetiole moderately developed. Basigastral costulae short and distinct. Petiole with a pair of stiff standing hairs. Dorsal surfaces postpetiole and gaster with stout standing hairs. Colour light yellowish brown to medium brown.

Paratypes. TL 3.0-3.1, HL 0.72-0.75, HW 0.52-0.55, CI 71-74, ML 0.42-0.43, MI 55-59, SL 0.50-0.54, SI 94-100, PW 0.32-0.34, AL 0.74-0.79 (6 measured). As holotype.

Type Material

Holotype worker, Madagascar: Marojejy R. N. I #12, 14°26'43.2"S, 49°47'8.3"E, 375 m., 18.xi.1993, rainforest, winkler app. #44.11127 (G. D. Alpert) (Museum of Comparative Zoology).

Paratypes. 5 workers and 1 queen (dealate) with same data as holotype but dated 20.xi.1993 and coded 108.13991, 108.13987, 108.13990, 108.13988; 1 worker and 1 queen (dealate) with same data as holotype but 665 m., 20.xi.1993 (Alpert et. al.), #106.10822, and #106.10820 (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 662, 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.