Over the weekend I blogged about a store in the business of selling Wasmannia auropunctata, one of the world’s most damaging pest ants. Much has been written about this species and its trail of ecological destruction. Google scholar, to illustrate my point, returns over 1500 papers mentioning this ant.
Wasmannia holds several other species, however. The graph above mentions a few of the better-studied congeners, and as you can see, most receive a pale shadow of the scientific attention accorded their cosmopolitan cousin.
I had the pleasure of meeting one of the relative unknowns, W. sulcaticeps, in a small cerrado fragment in Minas Gerais. They were tiny, only a couple millimeters long, and painfully shy. This ant, unlike W. auropunctata, did not leave an impression of impending pestilence.
The nest was small. It contained, under a rock, a few dozen workers and pupae. I don’t know whether the depauperate nature of the discovery was due to our locating just a fragment of the full colony, or whether these ants naturally live in small groups.
Why has Wasmannia auropunctata transformed into a global pest while the outwardly similar W. sulcaticeps remains a quaint and unobtrusive element of native South American habitats? Until someone takes the time to really study the behavior and biology of the non-famous species, we can only speculate.
(note: thanks to Bob Solar & Julio Chaul for assistance in the field, and to Jack Longino for taxonomic support.)