Research Article |
Corresponding author: James Wetterer ( wetterer@fau.edu ) Academic editor: Jack Neff
© 2015 James Wetterer.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Wetterer JK (2015) Geographic distribution of Leptogenys elongata (Buckley) and Leptogenys manni Wheeler (Hymenoptera, Formicidae, Ponerinae). Journal of Hymenoptera Research 46: 127-136. https://doi.org/10.3897/JHR.46.6555
|
Leptogenys elongata and Leptogenys manni (Hymenoptera, Formicidae, Ponerinae), the only described Leptogenys known from the continental US, were recently included on a list of exotic ants established in North America. To evaluate this possibility, I compiled and mapped published and unpublished specimen records of L. elongata and L. manni. Leptogenys elongata records have an essentially continuous distribution through central and eastern Texas (65 counties), southern Oklahoma (one county), and western Louisiana (eight parishes), south through much of Mexico (nine states), plus one questionable record from Colorado and one almost certainly erroneous record from the District of Columbia. Leptogenys manni records are known from much of Florida (22 counties), plus one isolated record from Georgia that needs corroboration. I found no credible evidence that L. elongata or L. manni have established populations anywhere beyond their native ranges.
Biogeography, exotic species, geographic range, native range
More than forty ant species have well-established populations in multiple areas of both the Old World and the New World, spread through human commerce (
Recently,
When a cosmopolitan ant species occurs in both the Old World and the New World, it is almost always clear that one of these ranges is entirely exotic. Within a species’ native hemisphere, however, it can be difficult to determine what geographic area constitutes the native range and what area, if any, constitutes the exotic range. When evaluating the native and exotic ranges of a species, researchers consider a spectrum of distributional, historical, evolutionary, ecological, and genetic information (see
Using published and unpublished records, I documented the known ranges of Leptogenys elongata and Leptogenys manni. I obtained unpublished site records from museum specimens in the collections of the
If a site record listed a geographic region rather than a “point locale,” and I had no other record for this region, I used the coordinates of the largest town within the region or, in the case of small islands and natural areas, the center of the region. In the only exception, I mapped
I was unable to map individually many records of L. elongata from caves because the site locations are kept secret to avoid vandalism. For example,
In total, I mapped 139 site records of Leptogenys elongata (including 106 from Texas) and 27 site records of Leptogenys manni (all but one from Florida) (Fig.
Earliest known records for Leptogenys elongata and Leptogenys manni in the US and Mexican states. * = probably erroneous. Site information given for unpublished records.
Leptogenys elongata | Earliest record |
---|---|
Texas | ≤1866 ( |
Mexico | ≤1870 ( |
Washington DC* | ≤1886 ( |
Colorado* | ≤1894 ( |
Louisiana | 1908 (collector unknown, Smithsonian Institution): Marksville |
Veracruz | 1941 ( |
Michoacán | 1952 ( |
Tamaulipas | 1964 ( |
Hidalgo | 1965 ( |
Jalisco | 1966 ( |
Nuevo León | 1972 (R.E. Gregg, antweb): Horsetail Falls |
San Luis Potosí | ≤2005 ( |
Morelos | ≤2007 ( |
Zacatecas | ≤2007 ( |
Oklahoma | 2014 (K. Roeder, J. Trager, pers. comm.): Kingston |
Leptogenys manni | Earliest record |
Florida | ≤1908 ( |
Georgia | ≤1947 ( |
Sites records of L. elongata in Texas came from 65 counties: Archer, Bandera, Bastrop, Bell, Bexar, Blanco, Brazoria, Brazos, Brown, Burleson, Burnet, Calhoun, Cameron, Comal, Concho, Coryell, Dallas, DeWitt, Edwards, Fayette, Fort Bend, Galveston, Gillespie, Grayson, Guadalupe, Harris, Hays, Hidalgo, Houston, Irion, Jack, Jefferson, Jones, Karnes, Kendall, Kerr, Kimble, Kinney, Kleberg, Liberty, Live Oak, Matagorda, McLennan, Menard, Milam, Nueces, Palo Pinto, Parker, Real, Refugio, Robertson, Runnels, San Jacinto, San Patricio, Schleicher, Stonewall, Sutton, Taylor, Travis, Uvalde, Victoria, Washington, Webb, Wharton, and Williamson (
The eight site records of L. elongata in Louisiana came from eight different parishes: Acadia, Avoyelles, Beauregard, Caddo, Calcasieu, Natchitoches, Rapides, and Vernon (
James Trager (pers. comm.) provided one unpublished record of L. elongata from Marshall County in southernmost Oklahoma (33.9°N; Table
The 22 site records of L. elongata in Mexico came from nine states (Table
Two of the new species in the elongata group that
The 26 site records of L. manni in Florida came from 22 counties: Alachua, Baker, Brevard, Columbia, Dixie, Gadsden, Gilchrist, Highlands, Indian River, Leon, Levy, Marion, Miami-Dade, Monroe, Orange, Pasco, Pinellas, Polk, Putnam, Taylor, Volusia, and Wakulla (
There are three problematic reports of L. elongata (from Colorado, the District of Columbia, and Maryland).
The single record of L. elongata from Colorado was based on specimens that Ezra T. Cresson collected (
The single record of L. elongata from the District of Columbia was based on specimens that Theodore Pergande collected (
Leptogenys elongata and L. manni are large, distinctive ants that have been rarely collected, perhaps due to largely subterranean habits. In fact,
In documenting the ranges of other species on
I thank M. Wetterer and J. Lattke for comments on this manuscript; M. Deyrup (