Current View: All Antweb

Cite this page

View in AntCat

Taxonomic History (provided by Barry Bolton, 2017)

Distribution:

(based on species list records)
Nearctic Region: Alabama, Arizona, Arkansas, Baja California Sur, California, Chihuahua, Colorado, Florida, Georgia, Hidalgo, Louisiana, Mississippi, México, New Mexico, North America, North Carolina, Sonora, South Carolina, Texas, United States
Neotropical Region: Americas, Argentina, Bahamas, Belize, Bolivia, Brazil, Caribbean, Central America, Chiapas, Colombia, Costa Rica, Cuba, El Progreso, El Salvador, Guanacaste, Guatemala, Guerrero, Haiti, Heredia, Honduras, Jalisco, La Libertad, Mato Grosso do Sul, Mexico, Michoacán de Ocampo, Morelos, Nayarit, New Providence, Nicaragua, Oaxaca, Paraguay, Pinar del Río, Puntarenas, Rivas, Sinaloa, Trinidad and Tobago, Uruguay, Veracruz, Yucatán, Zacapa
Palearctic Region: Georgia

Distribution Notes:

Pseudomyrmex pallidus occurs from southeastern United States (as far north along the eastern seaboard as New Jersey) west to southern California, and south through Mexico and Central America to Panama. Populations also occur in Cuba and the Bahamas.

Biology:

P. pallidus exhibits diversity in its choice of nesting sites. While it shows a preference for dead stalks or culms of herbaceous plants, it will also nest in dead twigs or branches of shrubs and trees in some localities.

By state, the Nearctic nest-site records are from the following plants (Ward, 1985):

• Florida: Ambrosia artemisiifolia, Andropogon, Bidens, Cladium jamaicense, Uniola paniculata.
• Georgia: Callicarba.
• Texas: Baccharis, Heterotheca subaxillaris, Iva ciliata, Melia azedarach, Prunus, Ptelea trijoliata, Uniola paniculata.
• Arizona: Gossypium thurberi, Quercus emoryi, Q. oblongifolia.
• California: Acacia greggii, Hyptis emoryi; also Baccharis salicifolia.

The number of functional queens in a colony varies widely. The majority of P. pallidus nests which Ward (1985) dissected from Texas and Florida were queenless or monogynous, but sometimes  larger numbers of mated, dealate queens cohabited (up to a maximum of 22). Since P. pallidus colonies are often polydomous, the number of queens per colony may be higher. P. pallidus alates have been collected in every month of the year, indicating that mating occurs in more than one season.

California

This species is relatively uncommon in southern California, and usually associated with woody shrubs or trees. In California nests have been found in dead branches of Hyptis emoryi, Acacia greggii and Baccharis salicifolia.

Identification:

Worker:

• median clypeal lobe laterally angled
• eye moderately elongate (REL2 0.53-0.65), and notably exceeding scape length (SL/EL 0.68-0.85)
• minimum distance between frontal carinae less than basal width of scape (MFC < 0.025)
• vertex with coriarious-punctulate sculpture
• pubescence moderately dense on abdominal tergite IV
• standing pilosity sparse, lacking on mesonotum and propodeum

Taxonomic Notes:

This is the most common and widespread member of the pallidus group in North and Central America. P. pallidus shows considerable geographical variation in size, sculpture, and body proportions. However the workers are consistently orange-brown in color, with contiguous frontal carinae (MFC < 0.025), moderately long eyes (REL2 > 0.52), and (at least weakly)  coriarious-punctulate sculpture on the vertex. No other Nearctic species possesses this combination of characters.

References:

Blum, M. S.; Callahan, P. S. 1963. The venom and poison glands of Pseudomyrmex pallidus (F. Smith). Psyche (Cambridge) 70: 69-74.

Peters, J. M. 1997. Microsatellite loci for Pseudomyrmex pallidus (Hymenoptera: Formicidae). Molecular Ecology 6: 887-888.

Ward, P. S. 1985. The Nearctic species of the genus Pseudomyrmex (Hymenoptera: Formicidae). Quaestiones Entomologicae 21: 209-246.

Taxonomic Treatment (provided by Plazi)

Specimen Habitat Summary

Found most commonly in these habitats: 132 times found in sand dunes, 8 times found in riparian woodland, 6 times found in mangrove, 5 times found in roadside near mangrove, 5 times found in pine forest, 4 times found in oak woodland, 0 times found in Mixed hardwood forest, 2 times found in Mojave desert wash, 3 times found in tropical dry forest, 3 times found in agricultural area, ...

Found most commonly in these microhabitats: 100 times ex Uniola culm, 17 times ex dead stalk Heterotheca, 9 times ex Baccharis twig, 9 times ex dead weed stalk, 4 times ex dead Uniola culm, 8 times ex weed stalk, 3 times ex dead Heterotheca stalk, 5 times ex Heterotheca stem, 4 times ex dead Cladium culm, 4 times ex grass stem, 3 times ex Willow, ...

Collected most commonly using these methods: 4 times search, 5 times ex dead sawgrass, 2 times sweeping, 4 times hand collecting, 3 times malaise, 2 times Nest in saw grass, 2 times Nest in saw grass stalk, 1 times Nest in twig above ground, 0 times On foliage of ash, 1 times On shrubs, 0 times Hollow twig, ...

Elevations: collected from 1 - 2280 meters, 123 meters average

Type specimens: Lectotype of Pseudomyrmex pallidus: casent0902900

See something amiss? Send us an email.

AntWeb is hosted and supported by the California Academy of Sciences.