Dna-Based Identification of Introduced Ermine Moth Species in North America (Lepidoptera: Yponomeutidae)

Three sibling species of European small ermine moths of the Yponomeuta padella complex have been collected in North America. To allow identification of fresh as well as dried specimens without host data, we examined these three species for diagnostic differences in their mitochondrial DNA (mtDNA). We report the sequence for a 2.3-kb region of mtDNA that includes the cytochrome oxidase I and II and transfer RNA (tRNA) leucine genes. The mtDNA of Y. malinellus Zeller showed 0.8-0.9% divergence from that of the other two species, Y. padella (L.) and Y. cagnagella (H¼bner). The latter two species had divergences of only 0.0-0.2;%. A survey of restriction sites in 44 collections demonstrated that Y. malinellus has distinct, diagnosable mtDNA in North America, whereas Y. padella and Y. cagnagella were not distinguished from each other by this method. The recent establishment and range expansion of Y. malinellus and Y. padella in western North America is currently being monitored by pheromone traps that potentially have some degree of cross-attraction. Restriction sites in amplified mtDNA should allow rapid confirmation of species identities of such dried collections. The method used to generate the particular diagnostic reported here can be expanded readily to include new species and populations.