Strumigenys metazytes

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

Known from different forest habitats, the few records of this species are noted as being from litter samples and a stump.

Identification

Bolton (2000) - A member of the Strumigenys pulchella-group. Four species in this group (Strumigenys abdita, Strumigenys creightoni, Strumigenys talpa, Strumigenys metazytes) do not have hairs on the anterior or lateral clypeal margins that are recurved or reflexed. Of these creightoni lacks erect hairs on the vertex close to the occipital margin, lacks an apicoscrobal hair, lacks a fine projecting hair at the pronotal humerus, and lacks standing pilosity on the mesonotum. In the other three species filiform or flagellate hairs are present at all these locations.

P. talpa separates from both abdita and metazytes as its main pilosity is entirely of long fine flagellate hairs. These occur as a pair on the vertex close to the occipital margin, a pair on the pronotal dorsum (as well as at the humeri), another pair on the mesonotum, and in numbers on the waist segments and especially the first gastral tergite. In both abdita and metazytes the hairs in many or all of these positions are stouter, simple and stiffly filiform, and at most evenly shallowly curved.

Of the last two species abdita is generally larger and its mandibles are usually longer (HL 0.53-0.60, HW 0.40-0.43, MI 17-22) than in metazytes (HL 0.51-0.52, HW 0.36-0.38, MI 16-17). Also, in abdita the anterior clypeal margin is very wide and has abruptly rounded anterolateral angles. The clypeal dorsum has broadly spatulate to spoon-shaped ground-pilosity that is very dense and conspicuous, and is very similar in shape and size to the hairs that fringe the lateral margins. Standing pilosity on the first gastral tergite is usually restricted to an apical and a basal transverse row, though some samples are known which have intermediate hairs present. By comparison metazytes has a short but very shallowly convex anterior clypeal margin that curves evenly into the lateral margins through widely rounded anterolateral angles. Its clypeal dorsum has minute inconspicuous spatulate ground-pilosity that is very much smaller than the large hairs that fringe the lateral margins. Pilosity on its first gastral tergite is more or less evenly distributed over the sclerite.

The only known Neotropical member of the pulchella-group, Strumigenys dispalata, is closest related to metazytes. Differentiation of the two is given under dispalata.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 36.58559° to 30.535°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

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

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

Nomenclature

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

metazytes. Pyramica metazytes Bolton, 2000: 121, fig. 108 (w.) U.S.A. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 123

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 1.9, HL 0.52, HW 0.36, CI 69, ML 0.09, MI 17, SL 0.28, SI 78, PW 0.23, AL 0.50. Anterior clypeal margin extremely shallowly convex, almost transverse in full-face view. Dorsum of clypeus with inconspicuous subappressed small spatulate hairs that are very much smaller than the anteriorly curved spoon-shaped hairs on the lateral clypeal margins. Eye with 3 ommatidia in the longest row (ca 6-7 ommatidia in total). Apicoscrobal hair present, flagellate. Cephalic ground-pilosity curved and narrowly spatulate; vertex near occipital margin with a pair, or transverse row of 4, longer more slender hairs that are filiform and more or less erect. Pronotal humeral hair very long and flagellate. Pronotal dorsum with 1 pair of erect filiform hairs. Mesonotal dorsum anteriorly with a pair of flagellate hairs, more posteriorly with at least 1 pair of shorter filiform hairs. Hairs on first gastral tergite erect, filiform and feebly curved, their apices weakly flattened or split. Hind basitarsus with a fine flagellate hair projecting from the dorsal (outer) surface close to its base. Dorsal alitrunk and petiole node finely superficially reticulate-punctate everywhere. Basigastral costulae coarse, strongly developed, extending over the basal quarter of the tergite.

Paratypes. TL 1.8-1.9, HL 0.51-0.52, HW 0.36-0.38, CI 70-74, ML 0.08-0.09, MI 16-18, SL 0.27-0.28, SI 73-76, PW 0.24-0.25, AL 0.48-0.50 (4 measured). Eye with 2-3 ommatidia in longest row (ca. 5-6 in total). Description of pilosity above is composite as the few available specimens all show some degree of abrasion. Mesonotal standing hairs may be more numerous than described.

Type Material

Holotype worker U.S.A. Kentucky, Edmonton Co., Mammoth Cave Nat. Park, Bruce Hollow, 24-27.viii.1967, Berl. 101 FM(HD), #67-145, log stump litter (S. Peck & A. Fiske) (The Natural History Museum). Paratypes 4 workers, U.S.A. Tennessee, Sevier Co., Chilhowee Mts, iii.1951, STR-199 (A. C. Cole) (Los Angeles County Museum of Natural History, Museum of Comparative Zoology).

Determination Clarifications

Bolton (2000) - It is possible that members of this species may be among the material mentioned by Brown (1953a:90) as possible new species, being noted again by Brown (1964:199) in his discussion of the “sp. near missouriensis”. However, I have not seen any of Brown's material that is obviously referable to metazytes, all that I have seen of it represents hyalina, a species belonging in the rostrata-group.

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 121, worker described)
Booher, D.B. 2021. The ant genus Strumigenys Smith, 1860 (Hymenoptera: Formicidae) in western North America north of Mexico. Zootaxa 5061, 201–248 (doi:10.11646/zootaxa.5061.2.1).
MacGown, J.A., Booher, D., Richter, H., Wetterer, J.K., Hill, J.G. 2021. An updated list of ants of Alabama (Hymenoptera: Formicidae) with new state records. Transactions of the American Entomological Society 147: 961-981 (doi:10.3157/061.147.0409).

References based on Global Ant Biodiversity Informatics

Clark A. T., J. J. Rykken, and B. D. Farrell. 2011. The Effects of Biogeography on Ant Diversity and Activity on the Boston Harbor Islands, Massachusetts, U.S.A. PloS One 6(11): 1-13.
Colby, D. and D. Prowell. 2006. Ants (Hymenoptera: Formicidae) in Wet Longleaf Pine Savannas in Louisiana. Florida Entomologist 89(2):266-269
Dash S. T. and L. M. Hooper-Bui. 2008. Species diversity of ants (Hymenoptera: Formicidae) in Louisiana. Conservation Biology and Biodiversity. 101: 1056-1066
Deyrup, M. and S. Cover. 2009. Dacetine Ants in Southeastern North America (Hymenoptera: Formicidae). Southeastern Naturalist 8(2):191-212
Forster J.A. 2005. The Ants (hymenoptera: Formicidae) of Alabama. Master of Science, Auburn University. 242 pages.
Ivanov K., L. Hightower, S. T. Dash, and J. B. Keiper. 2019. 150 years in the making: first comprehensive list of the ants (Hymenoptera: Formicidae) of Virginia, USA. Zootaxa 4554 (2): 532–560.
MacGown J. A., J. G. Hill, R. L. Brown, T. L. Schiefer, J. G. Lewis. 2012. Ant diversity at Noxubee National Wildlife Refuge in Oktibbeha, Noxubee, and Winston Counties, Mississippi. Mississippi Agricultural and Forestry Experiment Station Bulletin 1197: 1-30
MacGown J. A., and R. L. Brown. 2006. Survey of the ants (Hymenoptera: Formicidae) of the Tombigbee National Forest in Mississippi. Journal of the Kansas Entomological Society 79(4):325-340.
MacGown, J.A and J.A. Forster. 2005. A preliminary list of the ants (Hymenoptera: Formicidae) of Alabama, U.S.A. Entomological News 116(2):61-74
MacGown, J.A. and R.L. Brown. 2006. Survey of the ants (Hymenoptera: Formicidae) of the Tombigbee National Forest in Mississippi. Journal of the Kansas Entomological Society 79(4):325-340.
MacGown, J.A., J.G. Hill, R.L. Brown and T.L. 2009. Ant Diversity at Noxubee National Wildlife Refuge in Oktibbeha, Noxubee, and Winston Counties, Mississippi Report #2009-01. Schiefer. 2009.