Location: Biological Control of Pests ResearchTitle: Geographic spread of Strumigenys silvestrii (Hymenoptera: formicidae: dacetine)) Author
Submitted to: Terrestrial Arthropod Reviews
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2012
Publication Date: 6/11/2012
Citation: Macgown, J.A., Wetter, J.K., Hill, J.G. 2012. Geographic spread of Strumigenys silvestrii (Hymenoptera: formicidae: dacetine). Terrestrial Arthropod Reviews. 5:213-222. Interpretive Summary: As a result of increased global commerce, numerous alien species of plants and animals are being introduced to the US from various regions around the world, especially the tropics and Asia. As global warming continues, tropical species are able to spread farther north in the US. Numerous species of alien ants have been documented in the US, but the extent of the distributions of many of these species has not been studied, nor has their impact on the environment or their effects on other ant species. This is especially true with the minute pygmy snapping ants in the genus Strumigenys. Here we studied and mapped records of Strumigenys silvestrii. This tiny species was first reported to occur in the US in 1953 in Louisiana, but has since spread throughout the Southeast and even to California. This species is now commonly found in natural woodlands, rather than disturbed habitats. It is not known what impact this species will have on native species living in these habitats.
Technical Abstract: Strumigenys silvestrii is a tiny dacetine ant (Hymenoptera: Formicidae: Dacetini), apparently from South America, that has spread to the southern US and the West Indies. Strumigenys silvestrii has recently been found for the first time in the Old World, from the island of Madeira, mainland Portugal, and Macau. Here, we document the geographic spread of S. silvestrii. We compiled and mapped 59 site records of S. silvestrii. We documented the earliest known S. silvestrii records for 20 geographic areas (countries, major islands, and US states), including four areas for which we found no previously published records: Georgia (US), Grenada, Nevis, and St. Vincent. Strumigenys silvestrii is the only New World dacetine ant that has been recorded in the Old World. The distribution of its closest relatives and of known S. silvestrii specimen records supports the hypothesis that S. silvestrii is native to South America. Throughout its New World range (South America, the West Indies, and the southern US), many S. silvestrii records are from intact forests (usually indicative of a native species), but are very recent (usually indicative of an newly arrived exotic species).