Introduced Pheidole of the world: taxonomy, biology and distribution
Author
Sarnat, Eli M.
Author
Fischer, Georg
Author
Guenard, Benoit
Author
Economo, Evan P.
text
ZooKeys
2015
543
1
109
http://dx.doi.org/10.3897/zookeys.543.6050
journal article
http://dx.doi.org/10.3897/zookeys.543.6050
1313-2970-543-1
4E2375F0A3824F3CB7A4DCC5148A67B0
4E2375F0A3824F3CB7A4DCC5148A67B0
Taxon classification Animalia Hymenoptera Formicidae
Pheidole flavens Roger
Figs 77, Fig. 88d
Pheidole
flavens
.
Pheidole flavens
Roger 1863a
: 198 (s.w.q.) CUBA. Wheeler, W.M. 1905: 92 (m.). Neotype designated: Barrajagua, Las Villas, CUBA (E.O. Wilson):
Wilson 2003
: 419.
Pheidole
tuberculata
.
Pheidole exigua var. tuberculata
Mayr 1887
: 585 (s.) St. Catharina, BRAZIL. Subspecies of
flavens
:
Emery 1894
: 157. Junior synonym of
flavens
:
Wilson 2003
: 419.
Pheidole
vincentensis
.
Pheidole flavens var. vincentensis
Forel 1893a
: 411 (s.w.q.m.) SAINT VINCENT. Junior synonym of
flavens
:
Wilson 2003
: 419.
Pheidole
gracilior
.
Pheidole flavens r. gracilior
Forel 1901a
: 78 (s.w.q.) GERMANY (intercepted in quarantine, from West Indies). Junior synonym of
flavens
:
Wilson 2003
: 419.
Pheidole
haytiana
.
Pheidole flavens var. haytiana
Forel 1907: 6 (w.) HAITI, Port-au-Prince (Keitel). Wheeler, W.M. & Mann, 1914: 24 (s.q.m.). Junior synonym of
flavens
:
Wilson 2003
: 419.
Pheidole
spei
.
Pheidole flavens st. spei
Santschi 1930
: 77 (s.w.) CUBA, Pinar del Rio, Punta Esperanza, 4.i.2030, 7 s., 10 w. (Bierig). Junior synonym of
flavens
:
Wilson 2003
: 419.
Pheidole
aechmeae
.
Pheidole floridana subsp. aechmeae
Wheeler, W.M. 1934: 166 (s.w.) MEXICO, Camaron near Mirador, Vera Cruz, in
Aechmea bracteata
, No. 472 (Skwarra). Junior synonym of
flavens
:
Wilson 2003
: 419.
Pheidole
greggi
.
Pheidole greggi
Naves, 1985: 62, figs. 21, 45, 57 (s.w.) U.S.A., Miami, Florida, 19.xii.1945 (W.F. Buren). Junior synonym of
flavens
:
Wilson 2003
: 419.
Diagnosis among introduced
Pheidole
.
See notes under
Pheidole flavens
-complex. Neotype major: HW 0.72, HL 0.74, SL 0.42, CI 103, SI 58. Paraneotype minor: HW 0.34, HL 0.42, SL 0.34, CI 124. SI 100. Non-type measurements, major: HW 0.68-0.83, HL 0.74-0.88, SL 0.39-0.42, CI 87-97, SI 52-59. Non-type measurements, minor: HW 0.34-0.45, HL 0.39-0.49, SL 0.34-0.42, CI 81-93, SI 89-104.
Identification, taxonomy and systematics.
Pheidole flavens
belongs to the
Pheidole flavens
-complex along with a putatively large number of other nominal taxa. However, the
Pheidole flavens
group as conceived by
Wilson (2003)
is now known to be polyphyletic (
Economo et al. 2015
;
Moreau 2008
). Readers are referred to the
Pheidole flavens
-complex for additional discussion of identification, taxonomy and systematics. The taxonomy of
Pheidole flavens
and its close relatives remains in a state of confusion. It is beyond the scope of the present study to resolve this issue, but we contribute the following discussion as a step towards that goal.
Pheidole
flavens
was originally described by Roger from Cuba, but the type material is considered to be lost.
Wilson (2003)
designated a neotype from Cuba and synonymized a total of eight nominal taxa with
Pheidole flavens
. Of these,
Pheidole greggi
Naves (Florida) and perhaps
Pheidole flavens st. spei
Santschi (Mexico) are most similar to the Cuban neotype. They, together with the types of
Pheidole moerens subsp. creola
, are the only specimens examined thus far that have clearly reticulated rugulae posterior to the scrobes of major workers.
Naves'
(1985
: fig. 55) concept of
Pheidole flavens
Roger, at least as evidenced by his figures and descriptions, more closely matches our concept
Pheidole navigans
, a species that is spreading across the southeastern United States. The syntype major of
Pheidole flavens var. vincentensis
Forel differs substantially from the neotype in that the head is completely glossy between the rugulae, which are themselves entirely longitudinal and do not extend far beyond the maximum extent of the antennal scapes in repose. These characters make it at least superficially more similar to
Pheidole moerens
and
Pheidole navigans
.
Pheidole flavens r. gracilior
and
Pheidole navigans
were both described by Forel from workers intercepted at a Hamburg quarantine facility, which is testament to the dispersive ability of this complex. The syntype major of the latter species and that of
Pheidole floridana subsp. aechmeae
Wheeler, also described from Mexico, are quite similar.
Pheidole exigua var. tuberculata
Mayr has the strongly convex head and promesonotal dome of
Pheidole exigua
Mayr, and also exhibits tuberculate angles on the mesonotal declivity. Type specimens of
Pheidole flavens var. haytiana
Forel were not examined for this study.
The only material from outside Central America and the Caribbean that we were able to confirm as matching the
Wilson's
neotype was from Florida. The Florida populations referred to here as
Pheidole flavens
and
Pheidole navigans
are almost certainly heterospecific. We suspect that Nearctic records of
Pheidole flavens
outside of Florida such as those reported from Louisiana (
Colby and Prowell 2006
;
Dash and
Hooper-Bui
2008
) refer to either
Pheidole bilimeki
or the species we are treating as
Pheidole navigans
in the southeastern USA.
Biology.
The biology of
Pheidole flavens
, as currently conceived, was reviewed by
Wilson (2003)
with contributing observations by Jack Longino. The species prefers rotting wood, but also nest beneath the bark of trees, in dead knots on tree trunks, in sod on rocks, in the soil beneath stones, and in epiphyte masses. In the Caribbean it is recorded from forests and thickets from sea level to 900 m, and in Costa Rica it occurs in both wet and dry forests below 1000 m. The nest galleries are diffuse and irregular. Mature colonies are large containing up to thousands of workers. Workers collect small arthropods and will recruit to sugar baits.
Distribution.
Pheidole flavens
is among the most widespread and abundant species of its genus in the New World, although this range might be representative of multiple cryptic species. As currently conceived, however, we consider
Pheidole flavens
native from southern Mexico east through the Caribbean and south to Uruguay and northern Argentina. It is difficult to know whether the disjunction separating the western and eastern regions of South America is accurate or a sampling artifact. The Florida population is believed to have derived from an accidental introduction by commerce (
Deyrup et al. 2000
;
Wilson 2003
).
Risk
statement.
Pheidole flavens
(or at least
it's
very close relatives) are easily transported long distances, and are known to hitchhike with fresh plant material (
Wilson 2003
). However, the species is not known to cause significant impact to agricultural systems or native ecosystems, and is not considered a house pest (
Hedges 1998
;
Klotz et al. 1995
).