Pheidole anastasii

Pheidole anastasii
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Pheidole
Species:	P. anastasii
Binomial name
Pheidole anastasii Emery, 1896 Specimen Labels

A common and abundant forest species.

Identification

One of a number of species once suggested (Wilson 2003) to be the single highly variable species P. bilimeki. P. anastasii overlaps in its range with the now more strictly defined P. bilimeki. These two species maintain clear ecology differences, primarily in habitat preferences, that are diagnostic: P. anastasii nests in plant cavities in the shaded understory of mature or second growth wet forest. In contrast, bilimeki nests almost anywhere, including in rotten wood and under stones, but occurs mostly in open and highly disturbed areas.

The following can be helpful in separating bilimeki-like Phediole (Longino and Cox 2009):

1

• Scape relatively short (SI 95–108, lower cloud of points in Fig. 1); posterior margin of vertex somewhat flattened; color usually brown, yellow in northern parts of range . . . . . Pheidole bilimeki
• Scape relatively long (SI typically 103–125, upper cloud of points in Fig. 1); posterior margin of vertex more rounded (Fig. 2 B, C, E); color brown or yellow . . . . . 2

2

• Color clear yellow orange (gray brown in one population on Caribbean coast of Panama); typically nesting in live plant cavities in wet forest understory . . . . . Pheidole anastasii
• Color red brown to nearly black; typically nesting in open, disturbed habitats . . . . . 3

3

• Scapes relatively shorter (SI 108–114, see Fig. 1) (major worker with face uniformly red brown) . . . . . Pheidole jamaicensis
• Scapes relatively longer (SI 114–125, see Fig. 1) (major worker with face bicolored, dark red brown anteriorly, yellow posteriorly) . . . . . Pheidole punctatissima

Keys including this Species

• Key to US Pheidole

Distribution

Panama to Guatemala and southern Mexico (Chiapas).

Latitudinal Distribution Pattern

Latitudinal Range: 21.994665° to 8.407045°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Belize, Costa Rica (type locality), Guatemala, Honduras, Mexico, Nicaragua, Panama.
Palaearctic Region: Denmark.

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

Longino and Cox (2009) - Pheidole anastasii is a very abundant species in the low arboreal stratum of primary wet forest understory throughout Costa Rica. Nests may be found in almost any kind of cavity or sheltered space, and they may augment their nest space by building galleries and tunnels with carton or earthen construction. Nests have been observed in cavities in live stems of Psychotria (Rubiaceae), Witheringia asterotricha (Solanaceae), and Pausandra trianae (Euphorbiaceae), bracts of Ischnosiphon (Marantaceae), clasping petiole bases of Araceae, and the bulbous leaf bases of Tillandsia bulbosa (Bromeliaceae). It is a common opportunistic inhabitant of myrmecophytes such as saplings of Cecropia, portions of myrmecophytic Ocotea trees abandoned by Myrmelachista, and myrmecophytic Piper species. In every Costa Rican population of myrmecophytic melastomes (those with petiolar or laminar pouches; Conostegia setosa, Clidemia sp., Tococa sp.) that has been observed (Corcovado, La Selva, Tortuguero), this species has been the most abundant inhabitant. It was the dominant ant in a study of Conostegia setosa at La Selva (Tennant 1994). The species also nests in dead sticks and branches on or above the forest floor, and under bark flaps on tree trunks. When nests are in myrmecophytic melastomes, carton galleries may occur on the outside, connecting pouches and extending down the stem to the ground.

Colonies appear to be polydomous. Workers are generalist foragers, and may be taken at baits or in samples of sifted leaf litter. Colonies have occasionally been found as exotics in greenhouses in the United States (New York, Washington D.C.), which is no surprise given the frequency with which it is found in live plant cavities in Central America.

Specimens from the Caribbean coast of Panama, at the southernmost limit of the species, are the most aberrant. Minors and majors are identical to Costa Rican P. anastasii with respect to shape and measurements, but differ in color. Instead of being clear yellow orange, minors are a dusky gray brown and majors similar but with the posterior third or more of the head yellow (approaching Pheidole punctatissima). The specimens were collected in ant-plant domatia in forest understory, thus matching the behavior of P. anastasii.

At La Selva Biological Station, in lowland rainforest on the Atlantic slope, P. anastasii is one of the most abundant ants in the forest understory. At Sirena in Corcovado National Park in southeastern Costa Rica, P. anastasii is a common understory ant in mature and second growth forest, much like it is at La Selva.

Pheidole anastasii has a relatively consistent morphology and behavior over most of its range. Most collections are from Costa Rica (over 350 separate collection events in JTL's specimen database) but a few collections have been examined from Panama, Nicaragua, Honduras, Guatemala, and Mexico (Chiapas). All collections are from wet forest habitats, most from below 500m elevation but with a few to a maximum of 1200m. The northernmost record is from rainforest near Tikal in the Peten of Guatemala, and these specimens are indistinguishable from Costa Rican material.

Castes

Worker

Minor

Images from AntWeb

Paralectotype of Pheidole anastasii. Worker. Specimen code casent0904423. Photographer Will Ericson, uploaded by California Academy of Sciences.	Owned by MSNG, Genoa, Italy.

Worker. Specimen code casent0619900. Photographer Jeremy Pilllow, uploaded by University of Utah.	Owned by JTLC.

Worker (major/soldier). Specimen code casent0613680. Photographer Jeremy Pilllow, uploaded by University of Utah.	Owned by JTLC.

Major

Images from AntWeb

Lectotype of Pheidole anastasii. Worker (major/soldier). Specimen code casent0904422. Photographer Will Ericson, uploaded by California Academy of Sciences.	Owned by MSNG, Genoa, Italy.

Nomenclature

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

• anastasii. Pheidole anastasii Emery, 1896g: 76 (s.w.) COSTA RICA. Forel, 1901h: 78 (q.). Junior synonym of bilimeki: Wilson, 2003: 378. Revived from synonymy: Longino & Cox, 2009: 40.

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

Description

Longino and Cox (2009) - Pheidole anastasii, Pheidole bilimeki, Pheidole jamaicensis and Pheidole punctatissima share the following traits:

Minor worker: head width (not including eyes) 0.38 to 0.55mm; scape length 0.40 to 0.60mm; scape index (100 * scape length / head width) 95 to 125; face and mesosoma uniformly foveolate; promesonotal groove very weakly or not at all impressed; with short upturned propodeal spines; postpetiole broad and low, somewhat flattened, lower than petiolar node; first gastral tergite with anterior third to entire surface shagreened; pilosity on mesosomal dorsum sparse and stiff; pilosity on hind tibia fully appressed and short.

Major worker: head width 0.74 to 1.09mm; scape length 0.44 to 0.63mm; scape index 50 to 68; face largely foveolate rugose, with variable extent smooth and shiny posteriorly; hypostomal margin with two closely-spaced medial teeth; first gastral tergite with anterior third to entire surface shagreened.

In comparison with P. bilimiki, minor workers of Pheidole anastasii have relatively longer scapes and the posterior margin of the head is more rounded, both majors and minors are uniformly yellow orange.

References

• Anderson, P.S.L., Rivera, M.D., Suarez, A.V. 2020. “Simple” Biomechanical Model for Ants Reveals How Correlated Evolution among Body Segments Minimizes Variation in Center of Mass as Heads Get Larger. Integrative and Comparative Biology. (doi:10.1093/ICB/ICAA027).
• Birkemoe, T., Aak, A. 2008. Indoor infestations of two imported ant species (Pheidole anastasii Mayr, 1870 and Pheidole punctatissima Emery, 1896) (Hymenoptera, Formicidae) in Norway. Norwegian Journal of Entomology 55, 45–47.
• Dekoninck, W., Ignace, D., Vankerkhoven, F., Wegnez, P. 2012. Verspreidingsatlas van de mieren van België. Bulletin de la Société royale belge d’Entomologie 148: 95-186.
• Deyrup, M.A., Carlin, N., Trager, J., Umphrey, G. 1988. A review of the ants of the Florida Keys. Florida Entomologist 71: 163-176.
• Emery, C. 1896g. Studi sulle formiche della fauna neotropica. XVII-XXV. Bull. Soc. Entomol. Ital. 28: 33-107 (page 76, soldier, worker described)
• Forel, A. 1901m. Formiciden des Naturhistorischen Museums zu Hamburg. Neue Calyptomyrmex-, Dacryon-, Podomyrma- und Echinopla-Arten. Mitt. Naturhist. Mus. Hambg. 18: 43-82 (page 78, queen described)
• Khazan, E., Bujan, J., Scheffers, B.R. 2020. Patterns of ant activity and nesting ecology depend on flooding intensity in a Neotropical floodplain. International Journal of Tropical Insect Science (doi:10.1007/s42690-020-00149-0).
• Landero-Torres, I., Garcia-Martinez, M.A., Galindo-Tovar, M.E., Leyva-Ovalle, O.R., Lee-Espinosa, H.E., Murguia-Gonzalez, J., Negrin-Ruiz, J. 2014. Alpha diversity of the myrmecofauna of the Natural Protected Area Metlac from Fortin, Veracruz, Mexico. Southwestern Entomologist 39: 541-553.

• Longino, J. T. and D. J. Cox. 2009. Pheidole bilimeki reconsidered (Hymenoptera: Formicidae). Zootaxa. 1985:34-42.
• Sarnat, E. M., G. Fischer, B. Guenard, and E. P. Economo. 2015. Introduced Pheidole of the world: taxonomy, biology and distribution. Zookeys. 1-109. doi:10.3897/zookeys.543.6050
• Vázquez-Franco, C.M., Morrone, J.J. 2022. The genus Pheidole (Hymenoptera: Formicidae: Myrmicinae) in Puebla, Mexico. Revista Mexicana de Biodiversidad 93: e933820 (doi:10.22201/ib.20078706e.2022.93.3820).
• Wilson, E. O. 2003. Pheidole in the New World: A dominant, hyperdiverse ant genus. Cambridge, Mass.: Harvard University Press, [ix] + 794 pp.: 794pp (page 378, Junior synonym of bilimeki)

References based on Global Ant Biodiversity Informatics

• Adams, R.M.M. and J.T. Longino. 2007. Nesting biology of the arboreal fungus-growing ant Cyphomyrmex cornutus and behavioral interactions with the social-parasitic ant Megalomyrmex mondabora. Insectes Sociaux 54:136-143
• Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
• 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. T., and D. J. Cox. 2009. Pheidole bilimeki reconsidered (Hymenoptera: Formicidae). Zootaxa 1985: 34-42.
• Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
• Ottonetti L., L. Tucci, F. Frizzi, G. Chelazzi, and G. Santini. 2010. Changes in ground-foraging ant assemblages along a disturbance gradient in a tropical agricultural landscape. Ethology Ecology & Evolution 22: 73–86.
• Smith M. A., W. Hallwachs, D. H. Janzen. 2014. Diversity and phylogenetic community structure of ants along a Costa Rican elevational gradient. Ecography 37(8): 720-731.