Solenopsis geminata (Fabricius, 1804)

Tropical Fire Ant (TABER, 2000)

(ANTWEB: CASENT0173278). (Map 28)

Solenopsis geminata is an invasive ant transported by humans. It was collected for the first time in San Cristóbal in 1891 (EMERY, 1893). Solenopsis geminata is found on 20 islands and islets having invaded natural as well as fragmented habitats, successional forest, human settlements and agricultural zones. It is widely distributed along all ecological zones in the archipelago from littoral to humid zones. The species is commonly present in open areas and has been collected in stands of S. pedunculata, P. guajava, S. cordata, P. floribunda, B. graveolens, S. gordilloi, C. leucophlyctis, Homolepis glutinosa (Sw.) Zuloaga & Soderstr., H. mancinella, Gossypium barbadense L. and areas composed by ferns ( Pteridium aquilinum (L.) Kuhn), grasses ( Eragrostis pilosa (L.) P. Beauv. S. setosa, Cynodon sp.) and herbs ( Centella asiatica (L.) Urb. in Mart.). It can be found in mangrove litter, near lagoons, sandy dunes, beaches and wetlands.

Solenopsis geminata visits flowers of C. galapagosa, extrafloral nectaries of O. echios and J. thouarsii (MEIER, 1994), plant species infested by I. purchasi where it feeds on the honeydew produced by the scale insect (LINCANGO et al., 2010; HODDLE et al., 2013), as well as other plants like Senna alata (L.) Roxb., A. muricata and Acacia spp. infested by other Hemiptera species. The tropical fire ant has invaded all agricultural zones in the inhabited islands of the archipelago. It has been reported from the crops M. esculenta, A. comosus, M. acuminata, S. lycopersicum, S. tuberosum, Brassica oleracea var. botrytis L., Coriandrum sativum, S. betaceum, C. lanatus, M. paradisiaca, C. papaya, C. annuum, C. sativus, Z. mays, L. sativa, P. vulgaris, C. melo, Citrus spp ., B. oleracea var. italica, A. cepa, S. officinarum, C. arabica, and M. acuminata .

In urban areas it is a pest in houses and was collected in gardens, trash cans, stands of G. darwinii, C. sinensis, A. cherimola, S. purpurea, R. communis, C. limon, B. graveolens, M. paradisiaca, and mangroves. Nests of Solenopsis geminata occur in soil, on rocks, in open areas, on the edges of the roads, under stones, and in rotten trunks and roots of plants (e.g. Hyptis pectinata (L.) Doit. and Hyptis sidifolia (L'Hér.) Briq). This species often builds galleries on the bark of orange trees in agricultural areas, and constructs small tunnels under soil. Solenopis geminata is considered one of the most invasive species in Galápagos and a major threat to the terrestrial fauna (WILLIAMS & WHELAN, 1991; TAPIA, 1997; CAUSTON et al., 2006; WETTERER, 2011a; WAUTERS et al., 2014). It has been the target of several control programs (CAUSTON et al., 2012). The species is probably continuously reintroduced into Galápagos, as it has been intercepted in cargo holds of aircrafts arriving from Quito and Guayaquil and on several occasions from cargo holds of ships coming from the Guayaquil ports (ABG, personal communication). Ants have been collected from tourist boats traveling between the islands (LOMAS, 2008).