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The Large White butterfly (Pieris brassicae (Linnaeus, 1758)) originally from the Palaearctic and previously introduced to South Africa and Chile is detected on Rapa Nui (Easter Island). The records correspond to all stages of the life cycle: eggs, caterpillars, pupa and adults. Caterpillars were found feeding on Tropaeolum majus. The introduction is likely to have occurred from mainland Chile, as the species has not been reported in French Polynesia. A dark green coloration present on the underside of the wings is congruent with the one reported from the Chilean population. The origin of colonisation still remains to be tested using molecular tools.

Background Salas y Gómez is a small, volcanic island largely untouched by humans due to its diminutive size and remoteness. Since the waters surrounding Salas y Gómez were established as Motu Motiro Hiva Marine Park in 2010, marine investigations have been the primary research focus. Secondarily, nesting seabird communities have been censused since 2011. Methods and findings In 2016, terrestrial arthropods were sampled on the island. Two observers sampled two locations for 30 min per site. Fifteen morphospecies were identified including at least one likely undescribed species. Conclusions Our work represents the most comprehensive terrestrial arthropod inventory of Salas y Gómez island to date. We are hopeful the recommendations provided will spur additional research to both characterize the island’s arthropod community, as well as identify species of management concern.