Functional-group approach with scarab beetles (Coleoptera: Scarabaeidae): a low-cost alternative for monitoring biodiversity in El Salvador

Planning, implementing, and systematic revision of conservation policies are necessary to protect the biodiversity of a territory. This is critical in countries heavily impacted by anthropogenic activities, like El Salvador, where conserving biodiversity remnants must be a priority. Monitoring indicator groups represents a feasible option to review the status of biodiversity and the processes taking place in the country's conservation areas. We evaluated the suitability of Scarabaeidae beetle functional groups as ecological indicators to detect differences in the conservation status of two protected areas in El Salvador. We conducted monthly sampling for one year at each site, using pitfall, aerial, and UV-light traps to capture beetles. We detected differences in species richness, abundance, species composition, and turnover between the two areas. The results suggest the possibility of using this approach to monitor protected areas, to estimate the forest conservation status, and to evaluate the conservation strategies implemented to date. For the future, it is essential to determine if this is possible by replicating studies throughout the territory using standardized methodologies to obtain comparable results. The cost-benefit ratio of using a single indicator group is key in countries like El Salvador, where the economic aspect is a limiting factor for biological prospecting.