Paratrechina longicornis (Latreille, 1802)

Longhorn Crazy Ant (WETTERER, 2008)

(ANTWEB: CASENT0173232). (Map 13)

Paratrechina longicornis is a tramp species spread by human activities in tropical, subtropical and temperate areas around the world (KEMPF, 1972; BOLTON, 2006; WETTERER, 2015). Distributed over 16 islands and islets it was collected for the first time in Galápagos on Floreana Island between 1905–1906 (WHEELER, 1919). It nests between leaf litter, dead trunks and under stones. It is common in mangroves ( R. mangle, A. germinans, C. galapagosa) and is a scavenger and opportunistic diurnal species also invading natural areas (MEIER, 1994). Paratrechina longicornis is very well adapted to all vegetation zones in Galápagos. An entomological survey carried out in 1991 on Española Island showed that P. longicornis was abundant in dry areas (with Oxalis dombeyi A. St.–Hil, Physalis galapagoensis Waterf., B. graveolens, P. juliflora, C. lutea, I. triloba, Pennisetum pauperum Nees ex Steud., Mentzelia aspera L., Desmodium procumbens (Mill.) Hitchc., C. leucophlyctis, Alternanthera echinocephala (Hook. f.) Christoph., C. scouleri, L. peduncularis, P. aculeata, S. spicata, M. octogona and O. megasperma).

17 Paratrechina longicornis has been recorded visiting flowers of G. darwinii, A. germinans, C. molle, C. lutea, and extrafloral nectaries of giant endemic cacti O. echios and J. thouarsii (MCMULLEN, 1990, 1993; MEIER, 1994; CHAMORRO et al., 2012). It was collected on plants of G. darwinii, M. octogona, O. megasperma, Annona cherimola Mill., R. communis and C. lutea . It has been reported feeding on honeydew from I. purchasi and Ceroplastes spp. WETTERER (2008) mentions a possible case of mutualism with Coluocera maderae Wollaston, 1854, a beetle also recorded from Galapágos (PECK, 1993, 2005). Paratrechina longicornis is common in urban zones, inhabits flowerpots, buildings and streets. In gardens it can be found in plants of C. nucifera, C. papaya, Annona muricata L. and grass. It is present in agricultural areas of the inhabited islands of Floreana, Isabela, San Cristóbal and Santa Cruz where it is reported from crops of P. vulgaris, M. esculenta and C. sinensis .

Paratrechina longicornis is invasive in many parts of the world (WETTERER, 2008) and has probably been introduced several times to the islands. In Galápagos it is considered an invasive ant with a high potential to disperse and colonize new natural areas (CAUSTON et al., 2006). It is common in ports and airports and has been intercepted in commercial aircraft during quarantine inspections of products from mainland Ecuador (in A. comosus) in Baltra. The species was also found in cargo and on tourist ships (LOMAS, 2008; HERRERA, 2011), that probably facilitate its spread to and within Galápagos.