Strumigenys longinoi

AntWiki: The Ants --- Online
Strumigenys longinoi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. longinoi
Binomial name
Strumigenys longinoi
(Bolton, 2000)

Strumigenys longinoi inbiocri001282480 p 1 high.jpg

Strumigenys longinoi inbiocri001282480 d 1 high.jpg

Specimen Labels

Occurs in wet forest habitats. It inhabits leaf litter on the forest floor.

Identification

Bolton (2000) - The only member of the longinoi-complex in the Strumigenys excisa-group. Easily the largest species yet discovered in the group (HL 0.74-0.84, as opposed to a range of HL 0.44-0.66 in all other species) . This relatively large size, combined with its extremely flattened head and total lack of standing hairs, renders longinoi immediately recognisable within the group.

Longino (Ants of Costa Rica) - Mandible short and curving downward in profile; lateral head capsule with the antennal scrobe mostly or entirely smooth and shining; propodeal spines present (former Glamyromyrmex); leading edge of scape lacking erect setae; disc of postpetiole in dorsal view very broadly U-shaped or V-shaped, with an extremely deeply concave anterior face; spongiform tissue absent from ventral surface of petiole, postpetiole and first gastral sternite; face lacking erect setae; head in side view extremely flattened; pronotal humeral hair absent.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 10.33333° to 9.8712602°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Neotropical Region: Costa Rica (type locality).

Distribution based on AntMaps

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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.
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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.
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Biology

Explore-icon.png 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.

Castes

Worker

Images from AntWeb

Strumigenys longinoi inbiocri001283697 h 1 high.jpgStrumigenys longinoi inbiocri001283697 p 1 high.jpg
Paratype Pyramica longinoiQueen (alate/dealate). Specimen code inbiocri001283697. Photographer J. Longino, uploaded by University of Utah. Owned by INBio.

Nomenclature

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

  • longinoi. Pyramica longinoi Bolton, 2000: 173, fig. 128 (w.q.) COSTA RICA. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 122

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 2.9, HL 0.80, HW 0.69, CI 86, ML 0.16, MI 20, SL 0.34, SI 49, PW 0.32, AL 0.80. Outer margins of fully closed mandibles evenly but conspicuously convex in full-face view. Mandible with a basal row of 7 similar-sized stout conical teeth that immediately follow the basal lamella; tooth 8 slightly smaller than these and teeth 9 and 10 (apical) smaller still. Apex of basal lamella (in dissected paratype) level with apices of teeth 1-5, its basal length greater than the base length of teeth 1 + 2. Maximum depth of extremely flattened head 0.41 X HW. Eye with 4 ommatidia in longest row; side of head in front of eye punctulate but remainder of scrobe smooth. Pronotum bluntly angulate dorsolaterally, the mesonotum and propodeum somewhat more sharply marginate and the latter with a transverse arched carina at top of declivity between the spines. Propodeal spines elongate, acutely triangular and broad-based. Petiole and postpetiole without ventral spongiform lobes; base of first gastral sternite without trace of spongiform tissue. Petiole node in dorsal view longer than broad and with a minute rounded non-spongiform lobe on each side. Lateral lobes of the U -shaped postpetiole are aliform and sclerotised, not spongiform. Base of first gastral sternite flattened or even slightly concave on each side of the midline, stemite overhung by tergite laterobasally. Projecting hairs absent from upper scrobe margins and pronotal humeri. All dorsal and dorsolateral surfaces of head and alitrunk lack standing or projecting hairs of any form. Only minute appressed pubescence present, densest on clypeus where it is directed anteromedially, much sparser on head behind clypeus and on dorsal alitrunk. Waist segments and gaster with similar minute appressed pubescence, without standing hairs dorsally. In dorsal view side of petiole with a single pair of posteriorly curved hairs that arise just in front of the tiny lateral lobes. In dorsal view head finely shagreenate peripherally but centrally smooth with scattered minute punctures. Dorsal surfaces of alitrunk and waist segments with fine superficial sculpture only. Sides of alitrunk smooth and shining except for weak sculpture around the periphery. First gastral tergite with extremely feeble but quite dense basal costulae that span the width of the sclerite and are interspersed with even finer longitudinal striolae, so that the basal third of the tergite is quite densely, though faintly and superficially, sculptured.

Paraytpe. TL 2.5-3.0, HL 0.74-0. 84, HW 0.64-0.72, CI 85-87, ML 0.15-0.16, MI 19-21, SL 0.29-0.34, SI 44-51, PW 0.30-0.35, AL 0.72-0.80 (10 measured). Maximum depth of head 0.41-0.44 X HW.

Type Material

Holotype worker, Costa Rica: Alajuela Prov., Rio Penas Blancas, 1019'N, 84°43'W, 800 m., 23.v.1990, wet forest, ex sifted leaf litter, #2701 -s (J. Longino) (Instituto Nacional de Biodiversidad).

Paratypes. 11 workers with same data as holotype; 1 worker with same data but 26-28.iv.1987, #1579-s; 1 worker and 1 queen (dealate) Costa Rica: Provo Limon, Res. Biol. Hitoy-Cerere. 9°40'N, 83°02'W, 500 m., 30.viii.l985, wet forest litter sample, #970-s (J. Longino) (INBIO, The Natural History Museum, Museum of Comparative Zoology, Los Angeles County Museum of Natural History, University of California, Davis, National Museum of Natural History, and in coil. Longino).

References

  • Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria” 99:1-191.
  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 173, fig. 128 worker described)

References based on Global Ant Biodiversity Informatics

  • Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
  • Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.
  • Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/