Strumigenys dyseides

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

Collection records from Guyana and French Guiana show this ant inhabits forest leaf-litter.

Identification

Bolton (2000) - A member of the Strumigenys silvestrii-group. Within the group the species dyseides, Strumigenys gytha, Strumigenys quadrua, Strumigenys ruta and Strumigenys skia share the following characters.

1 Ventral surface of petiole does not have spongiform tissue.

2 Cephalic dorsum does not have a pair of short erect hairs near highest point of vertex (if any short standing hairs are present they are restricted to a single pair at the occipital margin).

3 With head in full-face view all spatulate or spoon-shaped hairs that fringe the upper scrobe margin are curved anteriorly.

4 Pilosity of the first gastral tergite is entirely of long flagellate hairs; without any other form of hair present.

S. quadrua is instantly diagnosed among these five species as it has only 4-segmented antennae and lacks a spiniform distal preapical tooth. The four remaining species form two related pairs. S. dyseides and gytha have the flagellate hairs on the first gastral tergite very fine and uniformly slender throughout their lengths, and standing hairs are absent from the mesonotum. In ruta and skia mesonotal standing hairs are present and the flagellate hairs on the first gastral tergite are thick for most or all of their lengths, usually appearing roughly ribbon-like for much of their lengths in any view. The components of each of these species-pairs can easily be separated by the characters given in the key.

Keys including this Species

Key to Neotropical and Nearctic Strumigenys

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 6.468333333° to 1.751666667°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina, Colombia (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.

‎

Castes

Nomenclature

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

dyseides. Strumigenys dyseides Bolton, 2000: 552, fig. 326 (w.) COLOMBIA.

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 1.8, HL 0.45, HW 0.34, CI 76, ML 0.30, MI 67, SL 0.28, SI 82, PW 0.23, AL 0.47. Spiniform preapical tooth of mandible separated from apicodorsal tooth by a distance about equal to its length. A minute preapical denticle also present, just proximal of mandibular midlength. Scape with a pronounced subbasal bend, the curved hairs on its leading edge slightly shorter than the maximum scape width. Ground-pilosity of head short and spoon-shaped; a pair of erect short simple hairs present on dorsum close to occipital margin; apicoscrobal hair fine. Promesonotum with short spatulate to spoon-shaped ground-pilosity; pronotal humeral hair very finely flagellate; mesonotum without standing elongate hairs of any form. Hairs on first gastral tergite sparse, flagellate, extremely fine. Pleurae and side of propodeum smooth. Propodeum with a pair of small teeth, subtended by a lamella that is obtusely triangular at the base of the declivity; posterior (free) margin of lamella shallowly concave. With petiole in profile the ventral surface without spongiform tissue; lateral spongiform lobe of petiole large and conspicuous; height of anterior face of node greater than length of its dorsum (excluding posterior collar). Petiole node in dorsal view broader than long; disc of postpetiole smooth and shining. Basigastral costulae longer than disc of postpetiole, toward the centre of the tergite the longest costulae exceed one-third the length of the sclerite.

Type Material

Holotype worker, Colombia: Putumayo, Villa Garzon, 23.vii.1977 (D. Jackson) (The Natural History Museum).

References

Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 552, worker described)
Franco, W., Ladino, N., Delabie, J.H.C., Dejean, A., Orivel, J., Fichaux, M., Groc, S., Leponce, M., Feitosa, R.M. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674, 509–543 (doi:10.11646/zootaxa.4674.5.2).

References based on Global Ant Biodiversity Informatics

Fichaux M., B. Bechade, J. Donald, A. Weyna, J. H. C. Delabie, J. Murienne, C. Baraloto, and J. Orivel. 2019. Habitats shape taxonomic and functional composition of Neotropical ant assemblages. Oecologia 189(2): 501-513.
Franco W., N. Ladino, J. H. C. Delabie, A. Dejean, J. Orivel, M. Fichaux, S. Groc, M. Leponce, and R. M. Feitosa. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674(5): 509-543.
Groc S., J. H. C. Delabie, F. Fernandez, M. Leponce, J. Orivel, R. Silvestre, Heraldo L. Vasconcelos, and A. Dejean. 2013. Leaf-litter ant communities (Hymenoptera: Formicidae) in a pristine Guianese rainforest: stable functional structure versus high species turnover. Myrmecological News 19: 43-51.
Groc S., J. Orivel, A. Dejean, J. Martin, M. Etienne, B. Corbara, and J. H. C. Delabie. 2009. Baseline study of the leaf-litter ant fauna in a French Guianese forest. Insect Conservation and Diversity 2: 183-193.
Medeiros Macedo L. P., E. B. Filho, amd J. H. C. Delabie. 2011. Epigean ant communities in Atlantic Forest remnants of São Paulo: a comparative study using the guild concept. Revista Brasileira de Entomologia 55(1): 7578.
Sosa-Calvo J., T. R. Schultz, and J. S. LaPolla. 2010. A review of the dacetine ants of Guyana (Formicidae: Myrmicinae). Journal of Hymenoptera Research 19: 12-43.