The risk of rediscovery: fast population decline of the localized endemic Chilean stag beetle Sclerostomulus nitidus (Coleoptera: Lucanidae) suggests trade as a threat

Rediscovery should be a celebratory event, but caution must be taken when making it public. Collectible species previously thought to be extinct are generally rare, which continuously increases the commercial value every time an individual is collected until extinction. This is the case with the recently rediscovered saproxylic beetle Sclerostomulus nitidus (Benesh, 1955), rediscovered in 2012, whose only known global population inhabits one sole mountain, Cerro Poqui, Chile. We sampled 146 dead logs per year and found that abundance per log of Sclerostomulus nitidus decreased by 93% in a 5-year period (2013–2018) and estimated the probability of finding at least one individual is likely to approach zero by 2030 following a linear trend. Sclerostomulus nitidus is listed as Critically Endangered by Chilean Law due to restricted geographic range, but we propose a need for new IUCN Red Listing resulting from our observations of ongoing population size reduction and the projected probabilities of finding an individual. While in the field, we witnessed ongoing collection and so present evidence of online trade of Sclerostomulus nitidus. Therefore, to complement the study of the ecology of S. nitidus, we suggest a focus on unifying national and international policies regarding traded or trafficked species. National policy might be up to speed, but international legislation regarding trading of wildlife, such as CITES, are outdated. Making national and international policy compatible would open possibilities for serious discussions with courier services regarding transparency and monitoring processes used to stop unfettered trading or trafficking to which recently rediscovered species are most vulnerable.