Male and female adults of Ypsolopha moltenii sp. n. (Lepidoptera, Ypsolophidae) are described and illustrated from the western slopes of the Andes of northern Chile. Larvae of Y. moltenii feed on inflorescences of the native shrub Adesmia verrucosa Meyen (Fabaceae). This finding represent the first species of Ypsolopha Latreille, 1796 described from mainland Chile and the first species of this genus with larvae feeding on the highly diverse South American genus Adesmia.

Ypsolophidae (Lepidoptera, Yponomeutoidea) is a worldwide micromoth family with more than 160 species described (van Nieukerken et al. 2011), whose monophyly has been supported in morphological (Kyrki 1990) and molecular (Sohn et al. 2013) studies. The widespread Ypsolopha Latreille, 1796 is the most diverse of the Ypsolophidae genera with more than 130 species described (Jin et al. 2013; Ponomarenko and Zinchenko 2013). Contrasting with the high species diversity of this genus in the Northern Hemisphere (e.g.: Sohn et al. 2010; Na et al. 2016), only seven species are known from the Neotropical region (Heppner 1984): five from Argentina, one from Peru and one from Chile.

The only Chilean representative of Ypsolopha, Y. telluris (Clarke, 1965), is endemic to the Juan Fernandez Islands (Clarke 1965); species of this genus have been not recorded from the mainland part of this country. The aim of this study is to describe and illustrate the first species of Ypsolopha from mainland Chile, recently discovered in a high elevation arid environment of the Andes in the northernmost part of this country.

The specimens used in this study were collected as larvae on inflorescences of the native shrub Adesmia verrucosa (Fabaceae) close to Socoroma village at about 3200 m elevation on the western slopes of the Andes of northern Chile (Figs 1–4), between May 2017 and April 2018. The collected larvae were placed in plastic vials and brought to the laboratory. Additional inflorescences were provided periodically until larvae finished feeding and pupated. Adults were mounted and their abdomens were dissected following standard procedures. The genitalia were stained with Eosin Y or Chlorazol black, and subsequently slide mounted with Euparal. Morphological observations were performed with a Leica M125 stereomicroscope and an Olympus BX51 optical microscope. Images were captured with a Sony CyberShot DSC-HX200V digital camera.

Abbreviations of institutional collections

MNNC Museo Nacional de Historia Natural de Santiago, Santiago, Chile

IDEA Colección Entomológica de la Universidad de Tarapacá, Arica, Chile

Figures 1–4. 

Habitat and host plant of Ypsolpha moltenii in the type locality. 1. Habitat of Y. moltenii close the Socoroma village, Arica Province, northern Chile, at about 3200 m elevation on the western slopes of the Andes. 2. A shrub of Adesmia verrucosa, the host plant of Y. moltenii. 3. Detail of a flower of A. verrucosa. 4. Fruits of A. verrucosa.

Although the highest species diversity of Ypsolophidae is currently known from the Northern Hemisphere, Sohn et al. (2013) suggested that the Neotropical species diversity of this family has been significantly underestimated. This suggestion is partially confirmed with the discovery of Y. moltenii, the first species of Ypsolopha described from mainland Chile. This finding also highlights the importance of surveying for larvae of Lepidoptera feeding on plants native to these little explored arid environments. The same approach has enabled the discovery of host-specialized representatives of micromoth genera and families previously unknown in Chile (e.g. Pereira et al. 2017; Brito and Vargas 2018).

Larvae of Ypsolopha can be found in silk webs on leaves of a wide range of plants (Dugdale et al. 1998), including representatives of the families Betulaceae, Berberidaceae, Caprifoliaceae, Celastraceae, Ephedraceae, Fabaceae, Fagaceae, Myricaceae, Pinaceae, Rosaceae, Salicaceae, Sapindaceae and Ulmaceae (Anikin et al. 2006; Robinson et al. 2010; Jin et al. 2013). Ypsolopha moltenii is the first Neotropical species of the genus with larvae feeding on Fabaceae. The larvae of the Palearctic Ypsolopha sarmaticella (Rebel, 1917) have been reared from two species of Caragana (Fabaceae) (Anikin et al. 2006). The geographic range of the host plant of Y. moltenii, A. verrucosa, is restricted to the northernmost part of Chile and southern Peru, where it is found on a narrow belt at about 3000–3800 m elevation (Macbride 1943; Trivelli and Valdivia 2009). Recently Gatica-Castro et al. (2015) have suggested the Vulnerable status for this shrub in its Chilean range. Accordingly, as larvae of Y. moltenii feed on reproductive parts of A. verrucosa, further studies should be performed to assess the effect of the feeding by the larvae of this micromoth on the reproductive biology of its host plant.

The South American genus Adesmia currently includes about 240 described species (Ulibarri and Burkart 2000), 130 of which are represented in Chile (Muñoz-Schick et al. 2016). Further sampling should be performed on additional species of Adesmia growing in different environments of the Andes to characterize the geographic range of A. moltenii and to assess whether this micromoth is able to use additional plants of the genus as hosts. Such a survey would be also a powerful tool to assess if additional species of Adesmia-feeding Ypsolopha are waiting to be discovered.

I thank Margarita Ponomarenko for valuable suggestions on a previous version of the manuscript; David C. Lees for kindly providing photographs of the lectotype of Y. hydraea deposited in the Natural History Museum, London, United Kingdom; Sebastián Espinoza-Donoso for editing the figures and Lafayette Eaton for checking the English. This study was supported by project UTA-MAYOR 9718–17, from the Universidad de Tarapacá, Arica, Chile.