
Platythyrea pilosula - Image by April Nobile/Antweb
Yesterday, the above photograph was uploaded to Antweb’s databases. Platythyrea pilosula is the final species to be imaged for the Ants of Paraguay project, marking the end of a sporadic and meandering study that I started in 1995 as a hobby during my stint in the Peace Corps. After combining several years’ worth of my field collections with the holdings at 19 entomological museums, I tallied 541 species for the country. This turns out to be too many species to keep track of in my head (I max out at about 300 or so), so I’ve found Antweb’s ready access to Paraguayan ant images very helpful.
An unexpected result of the survey was an unusual imbalance between the number of non-native ants present in Paraguay with the number of native species that are trampy or invasive elsewhere in the world:

This is precisely the opposite pattern than that shown by most regions. Consider California. With a land area equivalent to Paraguay, the state hosts 25 non-native species and perhaps only one or two natives that have established elsewhere.
Here’s something for the invasion biologists to chew on: Paraguay may be the only place in the world that is a net exporter of invasive ant species. I’m not volunteering to figure out why this is, but I do hope that having the regional ant fauna catalogued and imaged will make the job easier for those who do tackle it.