Toxicological trivia from November 05, 2014:  Sertox is receiving permanently questions to identify spiders, snakes, caterpillars and/or scorpions. Tityus is a large genus of thick-tailed scorpions (family Buthidae), the namesake of its subfamily Tityinae. As of June 2012, Tityus contains more than 200 described species distributed in Central America and South America, from Costa Rica to Argentina. We must consider that the scorpions in our area, Tityus confluens and  Tityus trivittatus measure 5-7 cm, the pedipalps are slender (important for specie identification), have a small nail (subaculear process) on the unit below venomous stinger that gives the appearance of having two stingers. Pictured in this article are particularly appreciated this detail, but for its peculiar position (defensive?) does not distinguish well if it is a:a) T. Trivittatus;b) T. confluens.

Correct answer: a. T. Trivittatus have yellowish brown color and two longitudinal bands clearer on the back (three longitudinal lines or dark brown), as seen in the other picture of the same specimen. From the toxicological point of view are considered equivalent risk.