Strumigenys cloydi

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Strumigenys cloydi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. cloydi
Binomial name
Strumigenys cloydi
(Pfitzer, 1951)

Pyramica cloydi casent0104334 profile 1.jpg

Pyramica cloydi casent0104334 dorsal 1.jpg

Specimen labels

Only known from a few collections, including one from a bayhead and another from a hardwood bottom forest.


Bolton (2000) - A member of the Strumigenys ornata-group. Of the three species in this group cloydi is isolated by its clypeal pilosity, described above. It differs from Strumigenys dietrichi and Strumigenys ornata in lacking a fan-like array of long hairs apicodorsally on the clypeus. P. cloydi also lacks the long, elevated wire-like mid-clypeal hairs characteristic of those two species, and apparently only ever has a single pair of flagellate hairs on the dorsolateral margin of the head , whilst two pairs are present in both ornata and dietrichi.

Most specimens examined have all hairs on the leading edge of the scape curved toward the scape apex, but some have 1-2 curved toward the scape base. Because material of this species is restricted to the type-series, and that has been poorly mounted , I am unable to tell if this is normal variation or the result of hairs having been displaced during mounting. For this reason cloydi is run out twice in the key.

Keys including this Species


Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


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.



The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • cloydi. Smithistruma cloydi Pfitzer, 1951: 198, figs. (w.) U.S.A. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 117. See also: Bolton, 2000: 111.

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



Bolton (2000) - TL 2.0-2.1, HL 0.56-0.60, HW 0.36-0.38, CI 60-64, ML 0.07-0.09, MI 13-16, SL 0.28-0.30, SI 79-83, PW 0.23-0.26, AL 0.54-0.60 (6 measured).

Fully closed mandibles with a gap between basal tooth and anterior clypeal margin that is longer than the length of the basal tooth. In full-face view clypeus longer than broad, its extreme anterior margin, between the lines of the inner mandibular margins, varying from extremely weakly concave to extremely weakly convex. Hairs that project from clypeal margins elongate and stout, weakly thickened apically and characteristically arranged: pair of hairs nearest midline on anterior margin curved strongly away from midline; next pair longer, on curve of anterolateral comers, directed outwards and usually shallowly curved posteriorly; third pair, close to midlength of side, directed outwards and usually inclined or weakly curved anteriorly (with feeble posterior curve in one worker); fourth pair close to j unction with preocular lamina, shorter and curved anteriorly. Dorsum of clypeus with short elevated spatulate hairs that are curved lateral l y or posteriorly; in profile the curvature distinct. Long flagellate hairs arranged as follows: in apicoscrobal position; a pair on cephalic dorsum close to occipital margin; at pronotal humeri; a pair on pronotal dorsum and another on mesonotum. Flagellate hairs also occur on first gastral tergite and dorsal (outer) surfaces of hind tibia and basitarsus.

Type Material

Bolton (2000) - Holotype worker and paratype workers, U. S. A.: Tennessee, Knoxville, 15.viii.1950 (Cloyd & Pjitzer) (National Museum of Natural History, Los Angeles County Museum of Natural History, Museum of Comparative Zoology, The Natural History Museum) [examined].


  • 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. 1999. Ant genera of the tribe Dacetonini (Hymenoptera: Formicidae). Journal of Natural History. 33:1639-1689. PDF (page 1673, Combination in Pyramica)
  • Bolton, B. 2000. The ant tribe Dacetini. Mem. Am. Entomol. Inst. 65: 1-1028 (page 111, redescription of worker)
  • Pfitzer, D. W. 1951. A new species of Smithistruma from Tennessee (Hymenoptera: Formicidae). J. Tenn. Acad. Sci. 26: 198-200 (page 198, figs. worker described)