Taxonomic History (provided by Barry Bolton, 2017)
Distribution:Nearctic Region: North America
, United StatesNeotropical Region: Americas
, Central America
, Costa Caribe Norte
, Costa Rica
, Francisco Morazán
, Islas de la Bahía
is distributed from Texas (United States) to Panama.
Among members of the oculatus
group (see Ward, 1989), workers of caeciliae
can be recognized by the following combination of features:
- small size (HW 0.51-0.61)
- head punctate-sublucid; at least some punctures separated by half their diameters or more, especially between the ocelli and compound eye, and immediately posterior to compound eye
- eyes relatively long (REL 0.48-0.55; REL2 0.72-0.81)
- petiole relatively short (PLI 0.79-0.91), with rounded dorsolateral margination
- medium to dark brown in color
The characteristic features of P. caeciliae
are its small size, relatively dark color, and the sublucid punctate appearance of parts of the head and mesosoma. It is distinguished from P. elongatus
primarily on the basis of this shiny appearance (all of their metric measurements overlap broadly, although P. elongatus
averages larger in size, with relatively longer eyes). Typically P. elongatus
workers have a densely punctate and opaque head, while in P. caeciliae
the punctures on the head are less dense, with (correspondingly) more extensive shiny interspaces between them, especially in the area immediately posterior to the compound eye; but both species vary considerably, and the extremes of sculptural variation come close to overlapping.
An old series of workers from Escuintla, Guatemala (Wheeler leg.) examined by Ward (1989) included both P. elongatus
, P. caeciliae
, and several individuals seemingly intermediate between the two. In western Mexico (Jalisco, Sinaloa), where P. caeciliae
is apparently absent, some P. elongatus
workers approach P. caeciliae
in head sculpture. On the other hand in Costa Rica, where the two species are broadly sympatric, intermediates appear to be absent.P. caeciliae
differs from P. cubaensis
by its smaller size (HW <0.62), relatively longer eyes (REL2 0.72-0.81), broader fore femur, and shorter petiole. While Mexican and Central American populations of these two species are rather distinct, Jamaican "caeciliae
" partly bridge the gap between the two. These Jamaican individuals may, in fact, represent small P. cubaensis
. The relationship of P. caeciliae
to the South American species, P. urbanus
, is even more problematic. The existing differences between the two are slight (see key to species in Ward, 1989) and not wholly diagnostic. More material, especially worker-associated queens and males from northern South America, will be needed to resolve this issue.
Ward, P. S. 1985. The Nearctic species of the genus Pseudomyrmex
(Hymenoptera: Formicidae). Quaestiones Entomologicae 21: 209-246.
Ward, P. S. 1989. Systematic studies on pseudomyrmecine ants: revision of the Pseudomyrmex oculatus
and P. subtilissimus
species groups, with taxonomic comments on other species. Quaestiones
Entomologicae 25: 393-468.
Specimen Habitat Summary
Found most commonly in these habitats: 3 times found in roadside vegetation, 2 times found in subtropical thorn woodland, 2 times found in suburban landscaped area, 1 times found in urban, 1 times found in Ecotone between pastures and low vegetation, mature wet forest, 1 times found in mangrove, 1 times found in tropical wet forest, 1 times found in wet forest, 1 times found in 2º tropical rainforest, 1 times found in Mangrove estuary, ...
Found most commonly in these microhabitats: 2 times foragers, 2 times ex dead branch of Prosopis glandulosa, pseudomyrme times collecting in mesquite tree at beach edge in front of cabina. #3424, 1 times strays, 1 times on branchfall, 2 times Malaise trap, 1 times concrete pedestal, 1 times sweeping vegetation, 1 times St. 804, general collecting in canopy Basiloxylon, 30m high., 1 times on low vegetation, 1 times nest in hollow twig, ...
Collected most commonly using these methods: 4 times search, 1 times hand collecting, 2 times Malaise, 1 times sweep.
Elevations: collected from 5 - 1100 meters, 250 meters average
Type specimens: Lectotype of Pseudomyrmex caeciliae: casent0907535
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