Description of a new Andean species of widow spider (Araneae, Theridiidae, Latrodectus)

We describe a new species of widow spider (Araneae, Theridiidae, Latrodectus) from the Andean region. DNA barcode sequences are provided. The species is documented from museum specimens across Peru and identified from photographs on iNaturalist, extending its inferred distribution into Ecuador, Bolivia, and Chile. We integrate specimen and citizen-science occurrences to generate a species distribution model using WorldClim bioclimatic variables, predicting highest suitability along temperate to high-elevation Andean regions. We discuss the utility and limitations of citizen-science imagery for delimiting and mapping species and summarize available information on clinical aspects of envenomation in Peru associated with the local “lucacha” widow spider.