Species Info General

Other common names include: (none)

This ant garnered the common name “Overlooked Thief Ant” by failing to receive a scientific description until 1989 – this despite being a widespread ant in Florida, one of the most populous states in the U.S where many full-time entomologists have been combing the leaf litter for generations.  Upon closer examination, however, and upon comparison to its many close cousins in that state, it’s more of a wonder that it got noticed at all: this is one of a group of a dozen of more virtually identical, tiny yellow ants.  Even though it didn’t receive official recognition until 1989, it turns out that this ant had hitched a ride to Hawaiʻi two decades earlier: Huddleston & Fluker (1968) reported collecting it on Oʻahu.  Thereafter, however, knowledge of its presence in Hawaiʻi faded from memory.  Few people were paying close attention to Hawaiʻi’s ants from the 1970s to the 1990s, so it’s not clear if this ant managed to thrive.  Curiously, a statewide survey in the 1980s and 1990s (Martin 2012) failed to detect it, however in 2000 it was rediscovered by Gruner et al. (2003), this time on both Oʻahu and Hawaiʻi.  Perhaps the population(s) detected by Huddleston & Fluker died out, and a new introduction from imported Florida material in the 1990s resulted in the detections starting in 2000.  In any case, by 2010 this ant was becoming widespread and common throughout the islands and today it is a firmly established member of our ant fauna.

The genus Solenopsis, to which this ant belongs, is best known for its “fire ants” – such as the Tropical Fire Ant (Solenopsis geminata) and the Red Imported Fire Ant (S. invicta).  However, around 85% of the nearly 200 species in the genus Solenopis species are not big, mean, stinging fire ants, but rather are tiny, inconspicuous thief ants.  Thief ants are commonly found to have the habit of spending most of their underground or deep in the leaf litter, sneaking into larger ants’ nests and raiding their brood and stealing from their food supplies.  Whether the Concealed Thief Ant engages in this sort of questionable behavior or not is as yet unknown: as a group, not a lot is known about the thief ants, or whether they all practice such thievery.  Thompson (1989) wrote that “Most of the information on thief ants indicated that they were present in relatively small numbers in the soil, and usually in close association with nests of larger ants.  . . .  I found that, despite their name, they were most often freeliving and highly predatory.  They readily killed and consumed colony-founding imported fire ant queens and the larvae of the sugar cane root stalk borer, Diaprepes abbreviatus (L.) . . . .  This indicates that thief ants are important subterranean predators and may have potential as biological control agents.”

In Hawaiʻi, this ant is often detected in large numbers in traps baited with peanut butter, suggesting that it is not above scouting out and about and scavenging food sources that are neither live prey nor associated with other ant species.  This ant is reported to raid cat food dishes on occasion, and its resemblance to Little Fire Ants causes consternation until the raider’s true identity is ascertained.