Strumigenys emmae (Emery, 1890) Strumigenys louisianae Roger, 1863

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 : 33-36

Strumigenys emmae (Emery, 1890)

Bow–Jawed Pygmy Snapping Ant

( DEYRUP et al., 2000) (ANTWEB: CASENT0173254). ( Map 33 )

This Pantropical species ( KEMPF, 1972; BROWN, 1949; BOLTON, 1983, BOLTON et al., 2006) is a tramp ant, which was introduced to Galápagos and has now been collected from four islands. It was reported for the first time in 1997 from a natural area in the Humid Zone of Floreana Island ( PEZZATTI et al., 1998). Strumigenys emmae is an inhabitant of leaf litter in moist habitats. On Alcedo volcano, however, it was found in dry habitats near S. affinis , B. graveolens , W. ovata and Bastardia viscosa (L.) Kunth) . This species can be found in urban areas (gardens mainly) and disturbed and cultivated areas. Strumigenys emmae has received very little attention in Galápagos, however it is a good colonizer and could be affecting terrestrial invertebrate ( DEYRUP et al., 2000; CAUSTON et al., 2006).

Strumigenys louisianae Roger, 1863

(ANTWEB: CASENT0173257). ( Map 34 )

Widespread in the Americas, from Southern United States to Argentina ( BROWN, 1961; BROWN, 1962; KEMPF, 1972; BRANDÃO, 1991; BOLTON et al., 2006; WETTERER 2014b). Strumigenys louisianae is an introduced ant that is only recorded on the inhabited islands. It was recorded for the first time in 1981–1982 on Santa Cruz ( Lubin, 1984). Nests can be found under soil and rotten wood. It is the most common Strumigenys species collected in the Transition and Humid Zone. In the Humid Zone it usually occurs in leaf litter where it preys on Collembola ( LUBIN, 1984; DEYRUP et al., 2000). Strumigenys louisianae also inhabits disturbed areas including gardens in human settlements. Other records come from forests of S. pedunculata , P. galapageium , M. robinsoniana and P. guajava . In cultivated areas it was found on the crops P. americana , C. arabica , B. oleracea var. capitata , Z. mays , A. comosus , S. betaceum , M. paradisiaca , S. quitoense , S. lycopersicum , Paspalum sp. and M. esculenta . According to LUBIN (1984), S. louisianae is one of the few species that is not affected by W. auropunctata . Nevertheless, recent observations from farms of Bellavista Village (Santa Cruz Island), revealed that nests of S. louisianae can be preyed upon by W. auropunctata . This ant is a predator of small arthropods, but little is known about its impact in Galapagos (WILSON, 1953; CAUSTON et al., 2006).

Figures

Map 33. Distribution of Strumigenys emmae (Emery, 1890).

Map 34. Distribution of Strumigenys louisianae Roger, 1863.