Tetramorium bicarinatum

Nomenclature

Species: Tetramorium bicarinatum (Nylander, 1846)

Syntype: NMW - ANTC18149 - CASENT0235199
Syntype: NMW - ANTC18150 - CASENT0235200
Syntype: NMW - ANTC18151 - CASENT0235201
Syntype: OUMNH - ANTC18159 - CASENT0235209
Syntype: ZSM - ANTC18160 - CASENT0235210
Syntype: BMNH - ANTC20278 - CASENT0901076
Syntype: OUMNH - ANTC20814 - CASENT0901374

General description

Tetramorium bicarinatum is a medium-sized ant with a reddish head, mesosoma and waist contrasting with a dark gaster. This species has a monomorphic worker caste with 12-segmented antennae, three-segmented antennal club, antennal scrobes, short antennal scapes that do not surpass the posterior margin of the head, a gradually sloped mesosoma, and strong propodeal spines. Like all myrmicines, T. bicarinatum has two waist segments and a gaster armed with a stinger. In the field it can be recognized by its bicolored appearance, medium size and strong recruiting to baits and food resources.Tetramorium bicarinatum is believed to be native to Africa, but is now widely distributed across the Pacific and other tropical regions. The species can achieve dense populations in disturbed habitats and is likely to adversely affect native biodiversity.

External links

Antweb | Antwiki

Diagnostic description

Diagnosis of worker among Antkey species

Worker caste monomorphic. Head shape roughly subrectangular. Antenna 12-segmented. Antennal club 3-segmented. Antennal scapes not conspicuously short; easily extended beyond eye level; do not extend beyond posterior margin of head. Antennal scrobe present. Antennal insertion surrounded by a raised sharp-edged ridge. 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; relatively far apart so that the posteromedian portion of the clypeus, where it projects between the frontal lobes, is much broader than one of the lobes. Anterior margin of clypeus notched. Mandibles triangular. Cephalic dorsum with short lateral rugae intersecting longer longitudinal rugae. Mesosoma with erect hairs. Pronotal spines absent. Propodeum armed with long robust spines. Slope of mesosoma gradual. Waist 2-segmented. Petiole with a square-shaped node; pedunculate; lacking large subpetiolar process postpetiole attached to lower surface of gaster. Postpetiole not swollen; in dorsal view not distinctly broader than long or distinctly wider than petiole. Erect hairs moderately distributed, long and thin. Bicolored; reddish brown with distinctly darker brown to black gaster.

Tetramorium bicarinatum is distinguished from its fellow congeners that are introduced in the United States by the following combination of characters: (1) petiolar node square-shaped (versus evenly rounded for T. lanuginosum and T. tonganum; versus wave-shaped for T. insolens and T. pacificum); (2) erect hairs long and thin (versus short and thick for T. caldarium and T. simillimum); (3) cephalic dorsum with short lateral rugae intersecting longer longitudinal rugae (versus primarily subparallel, non-intersecting longitudinal rugae for T. nr. caespitum and T. tsushimae); and (4) propodeal spines long and robust (versus small triangular teeth in T. nr. caespitum, T. tsushimae, T. caldarium and T. simillimum). The bicolored red and black appearance separate it from all but some specimens of T. caldarium and T. simillimum.

Distribution

Native range. Either SE Asia or Pacific island region.

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

<em>Tetramorium bicarinatum</em> at sugar bait

Tetramorium bicarinatum at cotton ball and sugar solution bait (Suva, Fiji).

<em>Tetramorium bicarinatum</em> at peanut butter bait

Tetramorium bicarinatum at peanut butter bait (Suva, Fiji). Notice the slow and deliberate movements and relatively short appendages.

Adult feeding from an extrafloral nectary. Photo by ©Alexander L. Wild, alexanderwild.com	Adult feeding from an extrafloral nectary. Photo by ©Alexander L. Wild, alexanderwild.com
Photo by ©Alexander L. Wild, alexanderwild.com	Lateral view of body, surface characters, adult worker. Body is orange to reddish brown, except for gaster which is darker brown to black. Separates Tetramorium bicarinatum, some specimens of T. caldarium and some specimens of T. simillimum from other congeners.
Lateral view of body, surface characters, adult worker. Erect hairs are long, acuminate, flexuous and moderately abundant, but never bifid. Separates Tetramorium bicarinatum, T. insolens, T. caespitum_cf, T. pacificum, T. tonganum and T. tsushimae from other congeners.	Anterior view of head, adult worker. Cephalic dorsum with short lateral rugae intersecting longer longitudinal rugae.
Anterior view of head, adult worker. Cephalic dorsum with short lateral rugae intersecting longer longitudinal rugae. Separates all other Tetramorium species from T. caespitum_cf and T. tsushimae.	Anterior view of antennal scrobe, adult worker. Antennal scrobe present.
Close-up view of frontal carina, adult worker. Frontal lobes relatively far apart so that the posteromedian portion of the clypeus, where it projects between the frontal lobes, is much broader than one of the lobes.	Close-up view of antenna, adult worker. Antennal insertion surrounded by a raised sharp ridge.
Close-up view of clypeus, adult worker. Anterior clypeal margin with median notch.	Lateral view of petiole, adult worker. Petiolar node and peduncle.
Lateral view of petiole, adult worker. Petiolar node is square shaped, with discrete and nearly flat anterior, dorsal and posterior faces. Separates Tetramorium bicarinatum, T. caldarium, T. caespitum_cf, T. simillimum and T. tsushima from other congeners.	Lateral view of petiole, adult worker. Petiolar node square-shaped.
Lateral view of propodeum, adult worker. Propodeal spines are well developed, long and spinose. Used in Antkey to separate species of Tetramorium.