Ants collected at Deaton Preserve, Greene County, Mississippi

Joe A. MacGown and JoVonn G. Hill

             We arrived at the Deaton Preserve near noon on 12 May 2006. After unlocking the gate we proceeded down the sandy dirt road for a couple of miles or so until we came to an open grassy area where a pipeline apparently ran through. This area (31°00'04"N88°42'08"W) was sandy and home to some gopher tortoises. There were several research plots that had been set up at various spots in the area, which we tried to avoid. The pipeline area itself consisted of short mowed grass with open sandy spots intermixed. This area was bordered by forest on either side with plenty of oaks (Quercus spp.), pines (Pinus spp., especially Pinus palustris), and yaupon holly (Ilex vomitoria) present with random openings with taller grasses and other vegetation present.

             As we roamed about the open areas we found many colonies of Solenopsis invicta Buren, although we didn't see any large mounds. Their colonies were mostly underground, under rotting logs, and under bark of dead trees. We saw hundreds of colonies of Dorymyrmex bureni (Trager) in the open areas with their distinctive small domed mounds. Many colonies of the light yellow colored Nylanderia arenivaga (Wheeler) was also seen nesting in the soil in open sandy areas. We found numerous colonies of Brachymyrmex patagonicus Mayr, a minute blackish colored exotic ant present nesting in soil and rotting wood. Alates of this species were present in the colonies. A few colonies of Pheidole obscurithorax Naves were also seen here. This is an introduced species that has made its way into southern Mississippi and appears to be heading northward. Collections of this species at this site represent a new county record. It is our largest Pheidole species in the state and the major workers are very impressive in appearance.

             We also found two species of Forelius including F. mccooki (McCook) and F. pruinosus Roger. Based on recent identifications of historic specimens in the Mississippi Entomological Museum, it is now that thought that historical records of Forelius pruinosus from Mississippi were misidentified and were actually F. mccooki. Forelius mccooki had been collected throughout the state, but Forelius pruinosus is thought to only occur in sandy habitats and was only recently discovered (by Hill and MacGown) to actually occur in Mississippi.

             Colonies of both Cyphomyrmex rimosus (Spinola) and Trachymyrmex septentrionalis (McCook) were seen in the area. These two attine ants are related to the leaf cutting Atta ants, which are not known to occur in Mississippi. Both species cultivate subterranean fungus gardens on a substrate of animal (mostly insect) and vegetative material. The fungus is used as sustenance for the colony. Colonies of Trachymyrmex are usually conspicuous and typically have a crescent shaped mound of soil piled up around the entrance hole to their nests in the soil. The colonies of Cyphomyrmex are much less obvious and are often under objects on the ground such as logs, rocks, cow dung, etc.

             A colony of another introduced species, Odontomachus ruginodis Smith, was found at the base of a large oak tree (Quercus spp.). The colony was in the wood of the tree with a small entrance hole about 3 cm in diameter. Due to the fact that much of the nest was in the wood, it was impossible to ascertain the size of the colony, but many workers exited the nest when it was disturbed. This species is a new state record for Mississippi and we have only found it otherwise in Mississippi in Jackson County. Odontomachus are large ants, approximately the size of carpenter ants. Both workers and queens possess elongate jaws, which arise from the middle of the clypeus. These jaws can be opened to about 180°, then snapped rapidly shut to capture prey or repulse intruders either by pushing them away by the force of the snap or by dismembering them. When the tips of their mandibles close upon a hard surface, the force may project their bodies high into the air up to several inches. Not only do they have large powerful mandibles, but they also can sting. This makes it quite challenging to put specimens into a vial of alcohol with fingertips. We have found this species to be very common in southeastern Alabama in the Gulf Shores area where it nests in situations where we would typically expect to find Camponotus species. It is possible that this species could have a negative impact on our native Camponotus species, which also utilize the same microhabitats.

             Sweep samples were made in the areas with taller grass, but no additional ant species were found. Additionally, a large pillowcase of litter was collected from the bases of small oak trees and from around rotting logs on the ground in the surrounding forest edge. Species in the litter sample included Hypoponera opacior (Forel), Discothyrea testacea Roger Strumigenys louisiana Roger, Cyphomyrmex rimosus, Solenopsis invicta, Solenopsis sp. cf. molesta (Say), Pheidole moerens Wheeler, Crematogaster ashmeadi Mayr, and Myrmecina americana Emery. Discothyrea testacea is a minute species that is only somewhat rarely collected, and it was nice to find that species. The other species found in the litter samples are all very common. Also found in the litter sample was a specimen of the small tenebrionid beetle, Poecilocrypticus formicophilus Gebien.  This species is thought to be a myrmecophile associated with the imported fire ant (MacGown, 2005). 

             Altogether, a total of 18 species of ants were collected at the Deaton Preserve site. Five species collected are considered to be exotic. Although Odontomachus ruginodis is known by the MEM to occur in Mississippi, it is a new state record and this was the most northern record of it to date. The collection of Pheidole obscurithorax also represents a new county record with this being the northern most point that this species has been found thus far. The most dominant ants we observed in the area were Dorymyrmex bureni and Solenopsis invicta, although there was no shortage of many of the other species of ants that we collected. Overall, the number of species we collected was fairly low, but not surprising as we were in a fairly restricted environment. Open areas often do not seem to support high numbers of species as compared to heavily forested areas. However, we only collected in this area for about an hour and a half and much of our collecting was confined to the open area. The Deaton Preserve is a relatively large area with varying habitat types and it is likely that many more species of ants occur here. To compare the species of ants from Deaton Preserve to other localities with similar habitats, click on the links below under the heading "links to ants of other sandhill or sand dune habitats".

Formicidae (arranged taxonomically by genus)

Forelius mccooki (McCook)
Forelius pruinosus
Nylanderia arenivaga (Wheeler)
Nylanderia faisonensis (Forel)
Dorymyrmex bureni
Brachymyrmex patagonicus Mayr
Hypoponera opacior (Forel)
Odontomachus ruginodis Smith
Discothyrea testacea Roger
Strumigenys louisiana Roger
Trachymyrmex septentrionalis (McCook)
Solenopsis invicta Buren
Solenopsis sp. cf. molesta (Say)
Pheidole dentata Mayr
Pheidole moerens Wheeler
Pheidole obscurithorax Naves
Crematogaster ashmeadi Mayr
Myrmecina americana Emery

Links to ants of other sandhill or sand dune habitats

Ants of Horn Island, Jackson County, Mississippi
Ants of Palestinean Gardens, George County, Mississippi
Ants of Bon Secour National Wildlife Refuge, Baldwin County, Alabama
Ants of Fall Line Sandhills Natural Area, Taylor County, Georgia
Ants of Ohoopee Dunes Natural Area, Emanuel County, Georgia
Ants of Big Hammock Natural Area, Tattnall County, Georgia

Literature Cited

MacGown, J. A. 2005.  A Collection of Poecilocrypticus formicophilus Gebien (Coleoptera:  Tenebrionidae) from a mound of the imported fire ant hybrid, Solenopsis invicta X richteri (Hymenoptera:  Formicidae) in Mississippi, USA. Entomological News 116: 367-368.  [pdf]