Hi, tentative to species but this looks like a South American Widow Spider, Latrodectus curacaviensis. I need to make a page for this to file it properly when I have more time.
I got a reply on another forum, which identified it as a Latrodectus mirabilis. From what I’ve seen and read, this seems to be correct. Thank you!
You’re welcome. Range-wise curacaviensis is a likely candidate, after looking over diagrams in “Abalos, 1980” this morning though I’m going to refrain from placing to species because the closest match I see to the abdominal pattern in there is L. quartus (fig. 40). The paper shows an isolated range for that species in Argentina so I initially overlooked it but I don’t want take a chance and misfile it. They can be tricky when the abdominal patterns have so much variation within just one species and there aren’t a lot of reliably IDed images for me to compare to.