Dung-associated arthropods from cattle dung-baited pitfall traps across seasons, Terceira Island (Azores, Portugal)

Dung-associated arthropods—particularly dung beetles (Scarabaeidae) together with rove beetles (Staphylinidae) and water scavenger beetles (Hydrophilidae)—provide key ecosystem services in cattle pastures (e.g., dung removal, nutrient cycling and pest suppression), yet year-round, standardised, event-based datasets remain scarce for Atlantic islands, limiting robust phenological and management comparisons. This resource publishes a one-year, monthly dataset from two cattle pastures on Terceira Island (Azores, Portugal) (University of Azores Campus (41 m) and Granja (380 m)), that experience contrasting grazing regimes (year-round grazing at Granja vs. grazing cessation in summer to allow maize cultivation at Campus). Arthropods were sampled from October 2022 to September 2023 using dung-baited pitfall traps (four traps per site per month, deployed for 2–4 days) and are shared as a Darwin Core Archive with an Event core (96 sampling events) and an Occurrence extension (1,701 occurrence records), including event-level minimum and maximum temperatures. In total, 13,882 individuals were collected across 4 classes, 16 orders and 61 families, assigned to 179 morphospecies, of which 147 were identified to full scientific name (12,865 specimens), providing a reusable baseline for analysing seasonal windows of activity and how pasture management reshapes dung-associated assemblages in temperate insular grasslands.