Genitalia morphology of a new gnorimoschemine micromoth (Lepidoptera, Gelechiidae, Gelechiinae, Gnorimoschemini) discovered in the Atacama Desert, northern Chile, fits the original description of Scrobipalpulopsis Povolný, 1987, a genus previously synonymized with Scrobipalpula Povolný, 1964. The generic assignment of the new species was assessed using a Bayesian phylogenetic analysis based on mitochondrial DNA sequences. The new species, the type species of Scrobipalpulopsis and another species recently transferred from this genus to Scrobipalpula were grouped in a monophyletic cluster distantly related to that of Scrobipalpula. Furthermore, an ancestral state reconstruction analysis suggested that the presence of two pairs of processes on the vinculum in the male genitalia represents a synapomorphy for the cluster of three species. Accordingly, the revalidation of Scrobipalpulopsis gen. rev. (type species Phthorimaea stirodes Meyrick, 1931) and the reinstated combination Scrobipalpulopsis lutescella (Clarke, 1934) comb. rev. are proposed. The micromoth Scrobipalpulopsis aguilaensis sp. nov., whose larvae feed on inflorescences of the Chilean endemic Glandularia gynobasis (Verbenaceae), is described and illustrated. Genetic divergence with congenerics was found to be 2.5–4.4% (K2P). This discovery represents the first record of Scrobipalpulopsis from the Atacama Desert.

DNA barcodes, florivorous larvae, Gnorimoschemini, micromoth, Neotropical, Verbenaceae

The New World micromoth genus Scrobipalpulopsis Povolný, 1987 (Lepidoptera, Gelechiidae, Gelechiinae, Gnorimoschemini) was originally described to include five Neotropical and one Nearctic species, with Phthorimaea stirodes Meyrick, 1931, from southern Argentina and southern Chile, as the type species (Povolný 1987). An elongated gnathos with a serrated apical ledge, serration on the ventral wall of the phallus and vinculum with two pairs of processes in the male genitalia, and a long colliculum on the membranous ductus bursae in the female genitalia were highlighted as morphological characters to differentiate representatives of this genus from those of the remarkably similar Scrobipalpula Povolný, 1964 (Povolný 1987). Two Neotropical (Povolný 1994) and one Nearctic (Powell and Povolný 2001) species were subsequently added to Scrobipalpulopsis. The genitalia morphology of the former two (Clarke 1965; Povolný 1990) agrees with the original genus description (Povolný 1987), whereas the latter species, originally described as Scrobipalpulopsis lycii Powell & Povolný, 2001, was referred as “an isolated taxon with distant relations to other members of the genus” due to a very deep and broad medial excision on the vinculum (Powell and Povolný 2001). As part of the checklist of the fauna of Gelechiidae of America north of Mexico, Scrobipalpulopsis was synonymized with Scrobipalpula and the two Nearctic representatives of the former [lycii and lutescella (Clarke, 1934)] were transferred to the latter (Lee et al. 2009).

Although the micromoth fauna of the Atacama and Puna biogeographic provinces of northern Chile has been little explored, recent discoveries suggest that plants native to the extremely arid environments of this part of South America host overlooked species of several micromoth families, including Gelechiidae (Vargas 2019, 2020). As part of surveys for Lepidoptera in this area, a few micromoths were recently reared from larvae collected on inflorescences of a native plant in the Atacama Desert. Subsequent examination of their genitalia revealed that these specimens represent a new gelechiid species whose morphology agrees with the original description of Scrobipalpulopsis (Povolný 1987). The aim of this study is to assess the generic assignment of this new species using a phylogenetic analysis based on mitochondrial DNA sequences and to provide a formal taxonomic description for it.

Generic assignment of the species of Neotropical Gnorimoschemini can be particularly difficult due to instability of genus-level circumscriptions (Corro Chang and Metz 2021). Phylogenetic analyses of mitochondrial DNA sequences have provided accurate generic assignment for species of several families of Lepidoptera (Lees et al. 2010; Moreira et al. 2012; Davis et al. 2020; San Blas et al. 2021; Nupponen and Sihvonen 2022). In the case of Gelechiidae, the agreement between phylogenetic analysis of mitochondrial DNA sequences and morphology has recently supported the recognition of new genera (Metz et al. 2019; Corley et al. 2020). The result of the Bayesian analysis of the present study provides support for the revalidation of Scrobipalpulopsis, because its type species was found to be not monophyletic with that of Scrobipalpula. This result agrees with morphology, as species of Scrobipalpula are recognized by a shovel-shaped gnathos and vinculum with one pair of processes in the male, and a ring-shaped colliculum in the female (Huemer and Karsholt 1998, 2010), while S. stirodes has an elongate gnathos with a finely serrated apex and a vinculum with two pairs of processes in the male and an elongate colliculum in the female (Povolný 1987). The result also supports the congeneric status of S. stirodes with S. aguilae sp. nov. and the Nearctic S. lutescella, because the three species were grouped with high support in a monophyletic cluster. Furthermore, the ancestral state reconstruction identified the presence of two pairs of processes on the vinculum in the male genitalia, a state shared by these three species, as a synapomorphy for Scrobipalpulopsis. However, further studies are needed for a better morphological delineation of this genus.

Although the Bayesian analysis found high support for the tribe Gnorimoschemini, relationships between the Gnorimoschemini genera were poorly resolved, as indicated by low supports. For instance, Phthorimaea operculella (Zeller, 1873) was sister to Scrobipalpulopsis, but only with 0.82 (PP). The results of maximum parsimony and maximum likelihood analyses (see Suppl. material 1) were similar to that of the Bayesian consensus tree, with high support for the distantly related clusters of Scrobipalpulopsis and Scrobipalpula and poorly resolved relationships between genera, but with a few differences in the number of polytomies. Better taxon sampling and analysis of additional molecular markers would be valuable to resolve the relationships between the genera of Neotropical Gnorimoschemini. Morphological characters must be also assessed using cladistics analysis to determine synapomorphies for each genus following the recent example provided by Corro Chang and Metz (2021).

The discovery of larvae of S. aguilaensis sp. nov. feeding on inflorescences of G. gynobasis adds Verbenaceae as a new host plant family for Scrobipalpulopsis. Previous host plant records for Scrobipalpulopsis were restricted to S. lutescella, whose larvae feed on flowers of Castilleja spp. (Orobanchaceae) (Clarke 1934; Powell and Povolný 2001; Nazari and Landry 2012). The association of Scrobipalpulopsis with a representative of Solanaceae was recorded by Powell and Povolný (2001). However, this record was based on lycii, a species currently included in Scrobipalpula (Lee et al. 2009). Host plant records can be useful to guide surveys to characterize distribution ranges of little-known species of phytophagous insects. The type locality of S. aguilaensis sp. nov. currently represents the only distribution record for this micromoth. However, this site (at about 1950 m) is at the lower limit of the wide elevational range of the host plant, which extends to 4000 m in the Andes (Rodriguez et al. 2018). Surveys for larvae of S. aguilaensis sp. nov. on inflorescences of G. gynobasis along this altitudinal gradient would be valuable to verify whether this micromoth occurs at higher elevations.

Despite the extreme aridity of the Atacama Desert, which is one of the oldest regions in the world under continuously arid conditions (Clarke 2006), its native plants support populations of native species of Lepidoptera that have remained overlooked until recently (Davis et al. 2020; Espinoza-Donoso et al. 2020; Vargas 2021). It is hoped that the discovery of S. aguilaensis sp. nov. will encourage further surveys to understand better and protect the still insufficiently studied biodiversity harbored by the extremely arid and fragile environments of the Atacama Desert.

I thank Jean-François Landry, Peter Huemer and Mark Metz for providing helpful comments and suggestions on a previous version of the manuscript, Vazrick Nazari for sharing the sequence of S. stirodes, Marcelo Vargas-Ortiz for DNA extraction and Lafayette Eaton for checking the English. The sequence of S. stirodes used in this study was obtained by Vazrick Nazari from the specimen ZMUC00029778 (Zoological Museum of University of Copenhagen) under permission of Ole Karsholt and the sequencing costs covered by Jean-François Landry. Ramya Manjunath provided assistance to request permission to use the sequence of S. stirodes from Vazrick Nazari. Financial support was obtained from Project “UTA-MAYOR 9729-21” from Universidad de Tarapacá.