Genetic divergence of a newly documented population of the cecidogenous micromoth Eugnosta azapaensis Vargas & Moreira (Lepidoptera: Tortricidae) in the Atacama Desert of northern Chile

Eugnosta azapaensis Vargas and Moreira, 2015 (Lepidoptera: Tortricidae) is a micromoth native to the Atacama Desert whose larvae induce fusiform galls in shoots of Baccharis salicifolia (Ruiz & Pav.) Pers. (Asteraceae). The presence of this cecidogenous tortricid was previously recorded only from the type locality, the Azapa Valley, Arica Province, northern Chile. However, fusiform galls on shoots of B. salicifolia were recently found in Chaca, another coastal valley of the Atacama Desert. The adults obtained from these galls were preliminarily identified as E. azapaensis based on morphology. Subsequently, to assess an additional source of evidence for the taxonomic identification of E. azapaensis in this new locality, sequences of the DNA barcode fragment of the cytochrome oxidase subunit I mitochondrial gene from the two localities were analyzed. Four haplotypes were detected, two restricted to Azapa and two restricted to Chaca. The genetic divergence (K2P) between haplotypes of each locality was 0.2–0.8%, while it was 1.1–1.4% between haplotypes of different localities, and 8.7–13.5% between the Chilean haplotypes and other species of Eugnosta Hübner, 1825. In addition, all the sequences of Azapa and Chaca were clustered in a well-supported group in a Maximum Likelihood (ML) analysis. Accordingly, divergence and ML analyses support the morphological identification of E. azapaensis in the Chaca Valley. Furthermore, although preliminary, the analyses suggest that the genetic variation of the populations of this insect could be geographically structured, a pattern that must be assessed in further studies.