Since its introduction to the U.S., the South American fire ant Solenopsis invicta has displaced its native congener S. geminata from many habitats. Repeated censusing indicates that the distribution of these ants in the northern Apalachicola National Forest is stable, with S. invicta monopolizing pond margins, both species occupying roadsides, and S. geminata found alone in the woods. A series of investigations revealed a number of differences between S. invicta and S. geminata that may play a role in determining the distribution of the two species. Attributes of S. invicta which have likely contributed to its displacement of S. geminata include: larger colony size, quicker colony growth facilitated by brood raiding, reproduction earlier in the year, and freedom from mermithid nematode parasitism. In the woods of the Apalachicola National Forest, the advantages enjoyed by S. invicta appear to be counteracted by a greater ability of S. geminata newly mated queens to survive the colony founding period. / Comparisons of the reproductive biology of S. invicta and S. geminata indicate striking differences. All mature S. invicta colonies are reproductively active during late spring and early summer, when mating flight activity is at its peak. Subsequently, the number of active colonies and the number of ants participating in mating flights gradually declines. The reproductive system of S. geminata is more complex, with colonies pursuing three different strategies. Two-thirds of the S. geminata colonies are reproductively active only in the late spring and early summer. About one-fifth are active only in the fall. A small number of colonies release alates in the spring/summer and again in the fall. The gynes of S. geminata exhibit a distinct dimorphism: those produced in spring and summer are larger, heavier, and fatter than gynes produced in fall. Both types are successful at becoming the sole queens of mature colonies, although several lines of evidence indicate that microgynes from fall mating flights do not found colonies independently. / Source: Dissertation Abstracts International, Volume: 55-04, Section: B, page: 1269. / Major Professor: Walter R. Tschinkel. / Thesis (Ph.D.)--The Florida State University, 1994.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_77167 |
| Contributors | McInnes, Donald Augustine., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 145 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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