Inferring the Provenance of an Alien Species with DNA Barcodes: The Neotropical Butterfly Dryas iulia in Thailand

The Neotropical butterfly Dryas iulia has been collected from several locations in Thailand and Malaysia since 2007, and has been observed breeding in the wild, using introduced Passiflora foetida as a larval host plant. The butterfly is bred by a butterfly house in Phuket, Thailand, for release at weddings and Buddhist ceremonies, and we hypothesized that this butterfly house was the source of wild, Thai individuals. We compared wing patterns and COI barcodes from two, wild Thai populations with individuals obtained from this butterfly house. All Thai individuals resemble the subspecies D. iulia modesta, and barcodes from wild and captive Thai specimens were identical. This unique, Thai barcode was not found in any of the 30 specimens sampled from the wild in the species\u27 native range, but is most similar to specimens from Costa Rica, where many exporting butterfly farms are located. These data implicate the butterfly house as the source of Thailand\u27s wild D. iulia populations, which are currently so widespread that eradication efforts are unlikely to be successful

Inferring the Provenance of an Alien Species with DNA Barcodes: The Neotropical Butterfly <i>Dryas iulia</i> in Thailand

<div><p>The Neotropical butterfly <i>Dryas iulia</i> has been collected from several locations in Thailand and Malaysia since 2007, and has been observed breeding in the wild, using introduced <i>Passiflora foetida</i> as a larval host plant. The butterfly is bred by a butterfly house in Phuket, Thailand, for release at weddings and Buddhist ceremonies, and we hypothesized that this butterfly house was the source of wild, Thai individuals. We compared wing patterns and COI barcodes from two, wild Thai populations with individuals obtained from this butterfly house. All Thai individuals resemble the subspecies <i>D. iulia modesta</i>, and barcodes from wild and captive Thai specimens were identical. This unique, Thai barcode was not found in any of the 30 specimens sampled from the wild in the species' native range, but is most similar to specimens from Costa Rica, where many exporting butterfly farms are located. These data implicate the butterfly house as the source of Thailand's wild <i>D. iulia</i> populations, which are currently so widespread that eradication efforts are unlikely to be successful.</p></div

Specimen information for sequences included in this analysis.

<p>Specimen information for sequences included in this analysis.</p

Collection localities of <i>Dryas iulia</i> butterflies on the Thai-Malay peninsula (unpublished data) [6], [7].

<p>Orange butterfly symbols indicate localities from which we sampled specimens for this study; black symbols indicate unsampled localities from which the species has been recorded. The image illustrates the wings of specimen DL-08-T033 caught on Phi Phi Don Island, Krabi Province, Thailand.</p

Relationships among <i>Dryas iulia</i> showing that wild-caught, Thai specimens have identical barcodes with specimens from the Phuket Butterfly Garden and no other samples collected in Central America and the Caribbean.

<p>a) Most parsimonious haplotype network of <i>D. iulia</i> constructed with 95% connection limit. The size of each circle is proportional to the number of specimens sharing that haplotype; the smallest circles represent a single haplotype and the largest, sixteen. The colors of the pie charts indicate proportional representation of the provenance of samples with that haplotype. Separation by a line indicates a single base pair difference between haplotypes; crosses represent haplotypes that would be 1 bp different than adjacent haplotypes, but were not sampled in this study. b) maximum likelihood bootstrap consensus tree of COI haplotypes from <i>D. iulia</i> and one outgroup. Codes refer to GenBank Accession Numbers and colors denote provenance of specimen collection. Numbers near selected nodes indicate refer to the following branch support values (maximum likelihood bootstrap support, Bayes posterior probability, parsimony bootstrap support, respectively):  = 40, –, –;  = 27, 0.62, –;  = 20, –, –;  = 27, 0.75, –;  = 31, 0.98, –;  = 26, 0.69, –;  = 100, 1, 100;  = 100, 1, 100.</p