Tetramorium bicarinatum (Nylander, 1846)

Herrera Léon Baert Wouter Dekoninck, Henri W., Causton, Charlotte E., Sevilla, Christian R., Pozo, Paola & Hendrickx, Frederik, 2020, Distribution and habitat preferences of Galápagos ants (Hymenoptera: Formicidae), Belgian Journal of Entomology 93, pp. 1-60 : 36-38

Tetramorium bicarinatum (Nylander, 1846)

Penny ant ( WETTERER, 2009 c)

(ANTWEB: CASENT0173284). ( Map 36 )

A tramp ant widespread throughout tropical, subtropical and temperate regions in the world ( WETTERER, 2009 c). This introduced species is found in all vegetation zones and most islands and islets of the Galápagos archipelago. Tetramorium bicarinatum occurs in natural and disturbed areas from the coast to the high–altitude Dry Zone. It was recorded for the first time in 1891 on San Cristóbal Island ( EMERY, 1893). It makes nests under rocks, in small holes in the soil, in bark, dry mangrove trunks, rotten logs and roots (e.g. B. graveolens ). It has been recorded visiting flowers of O. helleri ( CHAMORRO et al., 2012) and flowers and extrafloral nectaries of O. echios and J. thouarsii ( Meier, 1994) . Although it is well known as a predator of insects ( WETTERER, 2009 c) it also feeds on dead animals, like dead lizards, in arid environments (e.g. on Daphne Major Island). WHEELER (1924) reports workers of T. bicarinatum exploring the foliage of bushes where a great numbers of frigate birds and boobies were nesting. Specimens were collected from bare lava soil with few grasses and sedges, between litter in the crevices of rocks where seabirds rest, stands of C. pyriformis , mangrove leaf litter, areas with grass along sandy dunes and beaches (in Puerto Villamil), forests of B. graveolens (with Z. fagara , M. laricifolia , Cordia sp. , W. ovata , C. scouleri , D. lancifolius , A. filifolia and grasses) as well as in deciduous steppe forest of H. mancinella , herbs ( P. conjugatum , H. glutinosa , E. pilosa , Aristida subspicata Trin. & Rupr. , Rhynchospora sp. , C. asiatica , R. minima and S. setosa ), ferns ( P. aquilinum , P. tridens , Doryopteris palmata (Willd.) J. Sm., S. salviifolia ) mosses, sedges ( C. anderssonii ), grasses ( P. pauperum , S. setosa ), plants of B. graveolens , Chloris sp , Merremia sp. Exodeconus miersii (Hook. f.) D'Arcy and Scalesia villosa Stewart. In cultivated areas it attends scale insects and is reported in crops of S. officinarum , A. comosus , S. betaceum , Z. mays , M. acuminata , S. quitoense . In urban areas it was collected in gardens, trees of C. papaya , soil and leaf litter. It can easily be collected with pitfall traps, or tuna and honey baits.

Tetramorium bicarinatum is an introduced species impacting natural environments. In Galápagos it was identified as the probable cause of the extinction of C. macilentus on Española Island ( LUBIN, 1985). Recent expeditions by the authors to Fernandina Island show that it is probably the main competitor of the endemic ant C. planus , having invaded extensive areas around the trail to the summit. This suggests that its invasiveness potential is greater than previously thought ( CAUSTON et al., 2006). This species has been recorded in ports, airports and tourist boats, suggesting continuous reintroductions to and within the archipelago.

Figures

Map 36. Distribution of Tetramorium bicarinatum (Nylander, 1846).