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Solenopsis geminata

Nomenclature

Species: Solenopsis geminata (Fabricius, 1804)

Usage: valid
Vernacular name: Tropical Fire Ant

Syntype: OUMNH - ANTC20953 - CASENT0901430
Holotype: OUMNH - ANTC20954 - CASENT0901431
Holotype: OUMNH - ANTC20955 - CASENT0901432
Syntype: OUMNH - [node:field-collection-code] - CASENT0901969
Syntype: BMNH - [node:field-collection-code] - CASENT0902346
Syntype: BMNH - [node:field-collection-code] - CASENT0902347
Syntype: BMNH - [node:field-collection-code] - CASENT0902348

General description

Solenopsis geminata is a medium-sized reddish species with 10-segmented antennae, two-segmented antennal clubs, no antennal scrobes, nopropodeal spines, unsculptured heads and bodies, abundant thin and erect pilosity, and a polymorphic worker caste. The largest workers have disproportionately large and square-shaped heads. Like all myrmicines, S. geminata has a two-segmented waist and a gaster armed with a stinger. Solenopsis geminata is commonly referred to as the Tropical Red Fire Ant. It is an aggressive species with a painful sting and is known to cause damage to ecological and agricultural systems. For a more complete review of the biology, impacts and management of S. geminata, users are referred to the IUCN/SSC Invasive Species Specialist Group (ISSG) web page. Although S. geminata is an unpleasant ant, it is preferable to S. invicta. If either species is collected during invasive ant surveys, it is highly recommended that specimens from each sample be identified under the microscope to confirm the identity.

External links

Antweb | Antwiki

Diagnostic description

Diagnosis of worker among Antkey species

Worker caste polymorphic. Total length > 2 mm. Head ovoid (minors) to rectangular (majors). Antenna 10-segmented. Antennal club 2-segmented. Antennal scapes not conspicuously short; easily extended beyond eye level. Antennal insertions at least partly covered by frontal lobes; not surrounded by a raised sharp-edged ridge. Antennal scrobe lacking. Posterolateral corners of head unarmed, without spines. Eyes medium to large (greater than 5 facets); distinctly less than half head length. Frontal lobes do not obscure face outline between mandible and eye. Anterior margin of clypeus with two lateral teeth but lacking median tooth. Mandibles triangular. Pronotal spines absent. Propodeum lacking spines or teeth. Petiole with peduncle; subpetiolar process not developed as a flange or lobe. Shiny yellowish to brownish red.

Solenopsis geminata is easily separated from S. papuana by the polymorphic worker caste, the greater size (TL > 2.0 mm), and by the larger eye (> 5 facets). It is most reliably separated from S. invicta and S. richteri by the absence of a median tooth between the two lateral teeth on the anterior margin of the clypeus. This character is often difficult to see, and it is best to examine a moderate sample of specimens of different sizes before a confident determination can be made. Solenopsis geminata is most easily distinguished from the North American native, S. xyloni, by the lack of a well-developed subpetiolar process that forms a flange or lobe.

Look alikes

Solenopsis invicta, Solenopsis richteri, Solenopsis xyloni

Distribution

Click here for updated occurrence data and map on antmaps.org
Click here for updated occurrence data and map on GBIF.org

Videos of live ants

Solenopsis geminata on bait, Hawaii, 03-28-2011

Solenopsis geminata foraging on tree, Hawaii, 03-28-2011

<em>Solenopsis geminata</em> at sugar bait

Solenopsis geminata at cotton ball and sugar solution bait (Lautoka, Fiji).

<em>Solenopsis geminata</em> at peanut butter bait

Solenopsis geminata at peanut butter bait (Lautoka, Fiji). Notice the polymorphic worker caste, red color, and strong recruiting.

 
A major worker of the tropical fire ant. Photo by ©Alexander L. Wild, alexanderwild.com
A major worker of the tropical fire ant. Photo by ©Alexander L. Wild, alexanderwild.com
Major workers of the tropical fire ant are recognizeable for their unusually blocky heads. Photo by ©Alexander L. Wild, alexanderwild.com
Major workers of the tropical fire ant are recognizeable for their unusually blocky heads. Photo by ©Alexander L. Wild, alexanderwild.com
Photo by ©Alexander L. Wild, alexanderwild.com
Photo by ©Alexander L. Wild, alexanderwild.com
Dorsal view of body, entire, adult.
Dorsal view of body, entire, adult.
Anterior view of head, adult.
Anterior view of head, adult.
Anterior view of head, adult worker. Antennal scrobe absent.
Anterior view of head, adult worker. Antennal scrobe absent.
Lateral view of eye / ocellus, adult worker. Eye moderately sized (greater than 3 facets).
Lateral view of eye / ocellus, adult worker. Eye moderately sized (greater than 3 facets).
Lateral view of head, adult worker. Antennal club 2-segmented.
Lateral view of head, adult worker. Antennal club 2-segmented.
Anterior dorsal view of mandibles, adult.
Anterior dorsal view of mandibles, adult.
Anterior view of clypeus, adult worker. Clypeal anterior margin lacking median tooth.
Anterior view of clypeus, adult worker. Clypeal anterior margin lacking median tooth.
Anterior view of clypeus, adult worker. The anterior margin of the clypeus has two distinct lateral teeth that straddle the midline, but is missing a distinct median tooth between them. Used in Antkey to separate Solenopsis geminata and Solenopsis xyloni from Solenopsis invicta and Solenopsis richteri . This is arguably the most useful character for separating these species, but it can be difficult to see in some specimens.
Anterior view of clypeus, adult worker. The anterior margin of the clypeus has two distinct lateral teeth that straddle the midline, but is missing a distinct median tooth between them. Used in Antkey to separate Solenopsis geminata and Solenopsis xyloni from Solenopsis invicta and Solenopsis richteri. This is arguably the most useful character for separating these species, but it can be difficult to see in some specimens.
Lateral view of waist, adult worker. Petiole with a distinct and upright node.
Lateral view of waist, adult worker. Petiole with a distinct and upright node.
Lateral view of petiole, adult worker. Subpetiolar process weakly developed or absent.
Lateral view of petiole, adult worker. Subpetiolar process weakly developed or absent.
Lateral view of petiole, adult worker. The subpetiolar process is weak to absent, never as a well developed flange or lobe. If a process is present, it is located at the far anterior end of the petiole and maybe be difficult to see on most specimens. Used in Antkey to separate Solenopsis geminata from Solenopsis xyloni .
Lateral view of petiole, adult worker. The subpetiolar process is weak to absent, never as a well developed flange or lobe. If a process is present, it is located at the far anterior end of the petiole and maybe be difficult to see on most specimens. Used in Antkey to separate Solenopsis geminata from Solenopsis xyloni.