Which one of these two butterflies occurs on Hispaniola? Most of the recent literature lists the Columella Scrub-Hairstreak (Strymon columella) as occurring on the island, (e.g. Schwartz 1989, Takizawa et al 2003, Perez-Gelabert 2008). Warren et al (2012/2013) however lists the Mallow Scrub-Hairstreak (Strymon istapa) instead.
Robbins & Nicolay (1998a) published a nice paper dealing with the differences and the distribution of species in this tricky group of Hairstreaks. They say the Mallow Scrub-Hairstreak occurs on the Greater Antilles including Hispaniola, east to Puerto Rico. The Columella Scrub-Hairstreak on the other hand occurs on islands east of Puerto Rico only, which means the Columella doesn’t occur on Hispaniola.
Additionally, the specimen we have seen on Hispaniola in the field nicely fit the picture and description of the Mallow Scrub-Hairstreak (S. istapa) given in Robbins & Nicolay (1998a). This leads us to the conclusion that S. columella is off the list, the Mallow Scrub-Hairstreak (S. istapa) is on.
The Good, the Bad 'nd the Ugly 