Caddisfly biodiversity in Pernambuco state, Brazil: overcoming the biodiversity knowledge shortfall and insights into the effects of climate change

Knowledge of caddisfly diversity in Brazil has been increasing in the last two decades, but some regions have received less attention, particularly some states in the Brazilian Northeastern region. Nine caddisfly families, 24 genera, and 49 species are known in Pernambuco state. This study describes three new species and provides new distribution records for nine species and one genus, updating the total to nine families, 25 genera, and 61 valid species, making Pernambuco the second most species-rich state in northeastern Brazil. However, estimates indicate that around 50% of the state’s fauna remains unknown, an example of the Linnean shortfall. Most recorded species are known from few localities and distribution is concentrated in areas close to roads and conservation units, demonstrating a Wallacean shortfall. Caddisflies in Pernambuco occur across an elevation range of 18–1082 m a.s.l., with precipitation ranging from 507–1948 mm³/year, and temperatures between 13.2 °C and 33.6 °C; 80% of species are recorded in 1st order environments. Climate projections indicate a significant decrease in the temperature range, shifting from the current 13.2–33.6 °C to 17.9–33.6 °C, and precipitation range will decrease from 507 to 1948 mm³/year to 528–1428 mm³/year. These changes could lead to a high rate of local extinction. Climate change poses a serious threat, and additional efforts are needed to mitigate impacts and protect local biodiversity. Thus, priority should be given to efforts to inventory and describe Pernambuco’s caddisfly fauna, as well as research to assess potential climate change impacts, which will inform the formulation of public policies for biodiversity conservation and ecosystem protection in this important region. http://zoobank.org/urn:lsid:zoobank.org:pub:12DDC12A-E067-4CFB-94C4-DC0A89804EF8