Pheidole flavens

The wide range and abundance of Pheidole flavens is due at least in part to its ability to use different microhabitats as nesting sites. Judging from the extensive data of H. H. Smith (in Forel 1893j) on St. Vincent and J. T. Longino (1997) in Costa Rica, as well as my own collecting records, flavens prefers rotting pieces of wood, but also utilizes spaces beneath the bark of trees, dead knots on tree trunks, sod on rocks, the soil beneath stones, and epiphyte masses. On St. Vincent it occurred (in the early 1890s at least) in forests and thickets from sea level to 900 m, and in Costa Rica it is found today in both wet and dry forests. The nest galleries are diffuse and irregular, the queens hard to find, and mature colonies large, containing up to thousands of workers. Workers collect small arthropods: a captive colony from Trinidad I maintained for over a year eagerly harvested live oribatid mites, and the workers had no difficulty abrading through their hard, smooth exoskeletons. Workers also recruit to sugar baits. (Wilson 2003)

Identification
See the description in the nomenclature section.

Distribution
Pheidole flavens rivals Pheidole jelskii as the most widespread and abundant species of the genus in the New World. Or, put more cautiously, this species or (possibly) this tightly knit group of sibling species I have considered to be the single species flavens has this distinction. It ranges from Florida, where it likely was introduced accidentally by commerce, thence throughout the West Indies, Central America, and most of tropical and subtropical South America as far south as Santa Catarina in Brazil. P. flavens colonies are easily transported by human agency, especially as hitchhikers in nursery stock, as witness the synonymous “var. gracilior” and “var. navigans,” described by Auguste Forel from intercepted live ants in the German quarantine. I collected specimens from a thriving colony in a potted plant from Florida that had been transported to the office of the president of the World Wildlife Fund-U.S. in Washington, D.C. (at first I considered it a new sibling species but have since decided to place it within the broad variation of flavens). Even Forel’s “variety farquharensis” from Madagascar, whose types I have not been able to locate, is almost certainly, if it is truly flavens, to have the same provenance. (Wilson 2003)

This taxon was described from Cuba. It is also found in the United States, Ecuador, Brazil, Colombia, Peru, Argentina, Paraguay, Mexico, Belize, Guatemala, Honduras, Nicaragua, Panama, Costa Rica, Haiti, Dominican Republic, Bahamas, Madagascar, Germany, Barbados and Trinidad and Tobago.

Nomenclature

 *  flavens. Pheidole flavens Roger, 1863a: 198 (s.w.q.) CUBA. Wheeler, W.M. 1905b: 92 (m.). Senior synonym of aechmeae, gracilior, greggi, haytiana, navigans, spei, tuberculata, vincentensis: Wilson, 2003: 419.
 * tuberculata. Pheidole exigua var. tuberculata Mayr, 1887: 585 (s.) BRAZIL. Subspecies of flavens: Emery, 1894c: 157. Junior synonym of flavens: Wilson, 2003: 419.
 * vincentensis. Pheidole flavens var. vincentensis Forel, 1893g: 411 (s.w.q.m.) ANTILLES. Junior synonym of flavens: Wilson, 2003: 419.
 * gracilior. Pheidole flavens r. gracilior Forel, 1901h: 78 (s.w.q.) GERMANY (intercepted in quarantine, from West Indies). Junior synonym of flavens: Wilson, 2003: 419.
 * navigans. Pheidole flavens r. navigans Forel, 1901h: 79 (s.w.) GERMANY (intercepted in quarantine, from Mexico). Junior synonym of flavens: Wilson, 2003: 419.
 * haytiana. Pheidole flavens var. haytiana Forel, 1907e: 6 (w.) HAITI. Wheeler, W.M. & Mann, 1914: 24 (s.q.m.). Junior synonym of flavens: Wilson, 2003: 419.
 * spei. Pheidole flavens st. spei Santschi, 1930e: 77 (s.w.) CUBA. Junior synonym of flavens: Wilson, 2003: 419.
 * aechmeae. Pheidole floridana subsp. aechmeae Wheeler, W.M. 1934g: 166 (s.w.) MEXICO. Junior synonym of flavens: Wilson, 2003: 419.
 * greggi. Pheidole greggi Naves, 1985: 62, figs. 21, 45, 57 (s.w.) U.S.A. Junior synonym of flavens: Wilson, 2003: 419.

Description
From Wilson (2003): An extremely abundant, widespread species belonging to a complex of small, yellow, closely similar species that also includes Pheidole asperithorax, Pheidole breviscapa (=Pheidole perpusilla), Pheidole cardiella, Pheidole chloe, Pheidole exigua, Pheidole goeldii, Pheidole kuna, Pheidole mittermeieri, Pheidole moerens, Pheidole nitidicollis, Pheidole nuculiceps, Pheidole pholeops, Pheidole striaticeps and Pheidole trinitatis. P. flavens differs from them in the following combination of traits. Major: a shallow, relatively indistinct antennal scrobe present, its surface foveolate and opaque; weak rugoreticula often present mesad to the eyes and at the posterior end of the carinulae on the lateral dorsal surface of the head, which are variable in extent and sometimes absent; carinulae along the midline of the dorsum of the head reaching the occipital border but occipital lobes seen in full face view smooth and shiny; humeri usually with a small patch of rugoreticulum; lateral margins of pronotal dorsum also lined with short transverse carinulae; propodeal spine well-developed; postpetiolar node from above roughly trapezoidal; most of dorsal surface of head, all of mesosoma, and sides of waist foveolate and opaque. Minor: carinulae limited to space mesad to antennal fossa and occasionally also to the frontal lobes and frontal triangle; all of head and mesosoma and sides of waist foveolate and opaque; dorsum of waist and all of gaster smooth and shiny; occiput broad and shallowly concave.

P. flavens is easily confused with P. exiqua and P. moerens, also widespread and abundant species; see the differences under Diagnosis of those species in particular.

MEASUREMENTS (mm) Neotype major: HW 0.72, HL 0.74, SL 0.42, EL 0.08, PW 0.32. Paraneotype minor: HW 0.34, HL 0.42, SL 0.34, EL 0.06, PW 0.24.

COLOR Major and minor: medium to dark yellow.



'''Figure. Upper: neotype, major. Lower: paraneotype, minor. Scale bars = 1 mm.'''

Type Material

 * The neotype was selected after searches in collections containing Roger material failed to turn up the original types. The neotype, from the same country as the Roger type, fits the general concept of flavens held by systematists. (Wilson 2003)

Type Locality Information
CUBA: Barrajagua, Las Villas, col. E. O. Wilson.

Etymology
L flavens = yellow.

Additional References
Forel, A. 1893. Formicides de l’Antille St. Vincent, récoltés par Mons. H. H. Smith. Trans. Entomol. Soc. Lond. 1893: 333–418.

Roger, J. 1863. Verzeichniss der Formiciden-Gattungen und Arten. Berl. Entomol. Z. 7(Beilage): 1–65.

Text and images from this publication used by permission of the author.