A New Host Plant Record Helps to Understand the Geographic Distribution of a Neotropical Geometrid Moth (Geometridae)

Abstract

The spatial distribution of the resources that species are able to exploit limits their distribution ranges, while other abiotic and biotic factors constrain their occurrence within these limits (Quinn et al. 1997). The geographic ranges of host-specialized phytophagous insects, such as many members of Lepidoptera, strongly depend on the presence and abundance of their host plants in suitable habitats (Kozlov 2002, Neu et al. 2021). Therefore, detailed knowledge of host plant ranges of these organisms allows understanding their geographic ranges better (Basset et al. 2022), to forecast eventual shifts in their distribution patterns due to environmental changes (Schweiger et al. 2008) and to plan conservation practices (Clarke 2022). The distribution range of the Neotropical geometrid moth Pero obtusaria Prout, 1928 (Lepidoptera, Geometridae) extends from the Andes of southern Ecuador to the Atacama Desert of northern Chile (Poole 1987, Brehm & Fiedler 2005, Vargas & Hausmann 2008). In contrast, the occurrence of its only recorded host plant, the shrub Pluchea chingoyo (Kunth) DC. (Asteraceae) (Vargas 2011), is restricted between northwestern Peru and northern Chile (Moreira-Muñoz et al. 2016, Vilcapoma & Beltrán 2018). The Ecuadorian records of this moth clearly exceed the geographic range of its host plant, a pattern that could result from the mapping of vagrant adults or incomplete knowledge of the host plant range (Döring & Hoffman 2004). If records from southern Ecuador are based on locally reared moths instead of vagrants, P. obtusaria should be able to use at least one additional host plant whose geographic range includes this area. The aim of this contribution is to provide a new host plant record that helps to understand better the geographic distribution of this geometrid moth. The specimens examined in this study were reared from folivorous larvae collected in November, 2020 using a beating sheet on the shrub Baccharis salicifolia (Ruiz & Pav.) Pers. (Asteraceae) at about 1500 m elevation in the Livilcar Ravine (18° 33' 04"S, 69° 45'53"W), Arica Province, northern Chile. The specimens are deposited in the “Colección Entomológica de la Universidad de Tarapacá” (IDEA), Arica, Chile. Genomic DNA was extracted from two legs of an adult using the QIAamp Fast DNA Tissue Kit, following the manufacturer’s instructions. DNA purification, PCR amplification and sequencing of the barcode region (Hebert et al. 2003) with the primers LCO1490 and HCO2198 (Folmer et al. 1994) were performed at Journal of the Lepidopterists’ Society 77(2), 2023, 129–131