There are 2 petiole nodes and I don't think Myrmicinae spray Formic acid, I'm not sure though.If the image is one of the ant in question it is neither Pseudomyrmex or Solenopsis.
"The mother died of broncho aspiration, it is probable that the ants have bitten the trachea, which caused an inflammation and could no longer breathe,”
This could easily be the result of formic acid sprayed into the throat by any ants which got into the mouth/throat.
It even shows the stinger in the picture.
The picture that came with the article was the first "scary ant" the writer saw on the internet.
Edited by Batspiderfish, January 10 2017 - 10:46 AM.