This attractive blue tiger beetle is not easily mistaken for any other species. It has been recorded from Costa Rica, Panama, and Colombia, at 600 to 2000 meters above sea level.
Pseudoxycheila tarsalis hunts on ground that has little vegetation; these beetles are most active on sunny days. Males are territorial, while females range over greater distances. Males attempt to drive off rival males that enter their area. Activity (hunting, mating, fighting, ovipositing) happens mostly in the mornings. The species is "almost flightless" (Shepard et al. 2008).
One male aggression, Shepard et al. reported, "One male would chase the other, and if one beetle was caught, a fight ensued with both beetles rolling over and over together." Males would attempt to replace other males that were mounted on females, and they would also fight other males for food items.
Pseudoxycheila tarsalis can release defensive chemicals from its abdomen, and researchers have argued that the species is aposematic in its coloration. Researchers have also pointed out the similarity of this tiger beetle's color and markings with those of stinging velvet ants (wasps) in the genus Hoplomutilla, and thus have argued that P. tarsalis is a Mullerian mimic of the wasps (see for example Acorn 1988; Shepard 2001).
Photo data (upper two photos): 28 May 2015. Tuis, Cartago, Costa Rica.
Photo data (bottom photo): 15 September 2019. Altos del Maria, Coclé, Panama.