Species Info General

Other common names include: Mexican Elongate Twig Ant, Slender Twig Ant, Big Bicolored Slender Twig Ant

This large rusty-red-and-black ant is often mistaken for some sort of wasp – an impression that highlights the close evolutionary relationship between ants and wasps.  Indeed, this ant comes with a rather powerful sting, though as a colleague at Oʻahu Invasive Species Committee described it, the sting is “definitely not as painful as a wasp or bee sting”.  The common name “twig ant” refers to its habit of occupying hollow dead twigs up in trees.  Its sting and arboreal habit leads to interesting behaviors when it falls out of trees, as was eloquently elaborated upon by Deyrup (2017) who wrote about the several members of this genus found in Florida:

“All Florida species of Pseudomyrmex are equipped with a sting but are generally reluctant to use it, even on a myrmecologist who is breaking into a nest.  . . . Our species do sting readily if seized or slapped, and Floridians are often stung on the neck by one of these ants that has become dislodged from its home on a plant, and is climbing up the nearest tall object.  The ascent of a human by Pseudomyrmex . . . results in the ant climbing the back of the human, usually first hitting bare skin on the back of the neck.  One can brush off the ant with a quick flick of the gingers, but a slapping reaction gives the ant a chance to sting, sometimes more than once.  Most people seem to get a sensation of pain that starts slowly, builds over a few seconds to half a minute, and then begins to fade after a few minutes.  A small number of people get persistent swelling, and I have heard of one case of anaphylactic shock.  Considering that some species are very abundant, hundreds of Floridians must get stung by some species of Pseudomyrmex every month, without any lasting or traumatic effects.  It is probably far safer to be outdoors with the stinging ants than indoors, glued to the TV, whose anxiety-raising stories cause all sorts of ulcers, heart attacks, stress-induced eating, and displacement activity in the form of domestic violence.”  (Deyrup (2017)