Geographic distribution of Labidus coecus (Latr.) (Hymenoptera, Formicidae), a subterranean army ant

Abstract

Labidus coecus (Latreille) (Hymenoptera, Formicidae) is a New World subterranean army ant with an extensive geographic range. We compiled and mapped >650 site records for L. coecus, documenting the earliest known report for 27 geographic areas (countries, US states, and major West Indian islands), including three for which there are no previously published records: Margarita, Tobago, and Trinidad. With the new records, L. coecus has now been reported from 20 countries in Central and South America (all except Chile), three West Indian islands (Margarita, Trinidad, and Tobago), and four US states (Arkansas, Louisiana, Oklahoma, and Texas). The range of L. coecus appears to be essentially continuous, from Buenos Aires, Argentina in the south (~34.6°S) to Delaware County, Oklahoma in the north (~36.6°N). The three West Indian islands with L. coecus populations are all continental shelf islands that were connected to South America during periods of lower sea levels a few thousand years ago, so L. coecus populations on these islands have only recently become isolated. Labidus coecus commonly nests in caves, a microhabitat that may allow it to live in regions with otherwise inhospitable climates. Although recent papers listed L. coecus as an exotic species in North America, we found no evidence that L. coecus is exotic to any part of its known range.