The genus Calisto Hübner, 1823 is the only member of the diverse, global subfamily
Satyrinae found in the West Indies, and by far the richest endemic Caribbean butterfly
radiation. Calisto species occupy an extremely diverse array of habitats, suggestive
of adaptive radiation on the scale of other classic examples such as the Galápagos
or Darwin’s finches. However, a reliable species classification is a key requisite
before further evolutionary or ecological research. An analysis of 111 DNA ‘barcodes’
(655 bp of the mitochondrial gene COI) from 29 putative Calisto species represented
by 31 putative taxa was therefore conducted to elucidate taxonomic relationships among
these often highly cryptic and confusing taxa. The sympatric, morphologically and
ecologically similar taxa C. confusa Lathy, 1899 and C. confusa debarriera Clench,
1943 proved to be extremely divergent, and we therefore recognize Calisto debarriera
stat. n. as a distinct species, with Calisto neiba Schwartz et Gali, 1984 as a junior
synonym syn. n. Species status of certain allopatric, morphologically similar sister
species has been confirmed: Calisto hysius (Godart, 1824) (including its subspecies
C. hysius aleucosticha Correa et Schwartz, 1986, stat. n.), and its former subspecies
C. batesi Michener, 1943 showed a high degree of divergence (above 6%) and should
be considered separate species. Calisto lyceius Bates, 1935/C. crypta Gali, 1985/C.
franciscoi Gali, 1985 complex, also showed a high degree of divergence (above 6%),
confirming the species status of these taxa. In contrast, our data suggest that the
Calisto grannus Bates, 1939 species complex (including Calisto grannus dilemma González,
1987, C. grannus amazona González, 1987, stat. n., C. grannus micrommata Schwartz
et Gali, 1984, stat. n., C. grannus dystacta González, 1987, stat. n., C. grannus
phoinix González, 1987, stat. n., C. grannus sommeri Schwartz et Gali, 1984, stat.
n., and C. grannus micheneri Clench, 1944, stat. n.) should be treated as a single
polytypic species, as genetic divergence among sampled populations representing these
taxa is low (and stable morphological apomorphies are absent). A widely-distributed
pest of sugar cane, Calisto pulchella Lathy, 1899 showed higher diversification among
isolated populations (3.5%) than expected, hence supporting former separation of this
species into two taxa (pulchella and darlingtoni Clench, 1943), of which the latter
might prove to be a separate species rather than subspecies. The taxonomic revisions
presented here result in Calisto now containing 34 species and 17 subspecies. Three
species endemic to islands other than Hispaniola appear to be derived lineages of
various Hispaniolan clades, indicating ancient dispersal events from Hispaniola to
Puerto Rico, Cuba, and Jamaica. Overall, the degree of intrageneric and intraspecific
divergence within Calisto suggests a long and continuous diversification period of
4–8 Myr. The maximum divergence within the genus (ca. 13.3%) is almost equivalent
to the maximum divergence of Calisto from the distant pronophiline relative Auca Hayward,
1953 from the southern Andes (14.1%) and from the presumed closest relative Eretris
Thieme, 1905 (14.4%), suggesting that the genus began to diversify soon after its
split from its continental sister taxon. In general, this ‘barcode’ divergence corresponds
to the high degree of morphological and ecological variation found among major lineages
within the genus.