Abstract:
The genus Eois (Larentiinae) comprises an important part of a megadiverse assemblage of geometrid
moths in the mountain rainforests of southern Ecuador. Owing to the diversity of morphotypes found in
this genus, the abundance of many of its component species, and the close relationships with larval
food plants in the genus Piper, the genus Eois was chosen as a target for more detailed investigation on
the suitability of DNA barcode applications and phylogenetic relationships. COI barcode sequences
(676 bp) were generated from 342 individuals to establish an inventory of DNA barcodes from one
study area (Reserva Biológica San Francisco). This inventory can be used to match larvae to known
adult samples without rearing, and will therefore be of vital help to extend the currently very limited
knowledge about food plant relationships and host specialization. Analyses of barcoding sequence
divergence showed that species delimitations based on external morphology alone result in broad
overlap of intra- and interspecific distances. Species delimitation at a 3% pairwise genetic distance
threshold eliminated all but 3 out of 9 cases causing overlap and delimitation at a 2% threshold resulted
in a clear barcoding gap. 30 previously unrecognized species were identified solely on morphological
evidence, and their species status was subsequently supported by barcode sequence data. In addition to
that 9 putative species could be recognized by threshold based delimitation. Hence, the present study
increased the number of Eois species recorded from that small area of Andean mountain forests from
99 to 129 (morphology-based) or even 138 (sequence-based). Notably there are no cases where two or
more previously known morphospecies had to be lumped. We acquired elongation factor 1-alpha
sequences and extended COI sequences of 102 individuals amounting to a combined sequence dataset
of ~2200 bp. These represented at least 70 Eois species plus a range of outgroup taxa. Maximum
parsimony and Bayesian inference of phylogeny were employed to estimate relationships within Eois.
Monophyly of Eois was always strongly supported. Phylogenetic trees revealed that all included wingpattern
types except for one evolved only once. The exception to this rule occurred in the most basal
clade whose species closely resemble those in a clade higher up in the tree. This may represent an
ancestral character state or the result of convergent evolution. Additionally it could be determined that
species known to feed on Piper are spread over most of the major clades within Eois, indicating that
the host plant relationship with Piper is indeed a widespread trait among the Neotropical members of
the genus and not just occurs in certain subclades. The number of species and individuals recorded
from Piper is however skewed towards two subclades. Within the subfamily Larentiinae the genus Eois
has traditionally been placed close to the tribe Eupitheciini, but there is presently no support for such a
placement in our phylogenetic analyses.
