Freshwater invertebrates are natural ambassadors that can engage local scientific and non-scientific human audiences. Here, I present a poster about microcaddisflies that I have been using to get people excited about local biodiversity in the Willamette Basin in Oregon, USA.
Microcaddisflies are aquatic insects that are fascinating but can be overlooked due to their small size. Because of this, we probably have an incomplete understanding of which species call the Willamette Basin home. Larval microcaddisflies, like many other caddisflies, build and live in cases, with most genera having portable cases. However, in contrast to other caddisflies, they only build cases in their final larval instar. Adult males in the genus Hydroptila have unique, eversible androconia on their heads that produce pheromones for attracting mates, and the females of at least some microcaddisfly species dive and swim to lay their eggs on underwater substrates. Published records indicate there are 33 microcaddisfly species in Oregon, and by consulting literature and the collection records of David E. Ruiter, I could confirm that 14 of these occur in the Willamette Basin. Three additional species not previously reported from Oregon in published literature had records from the Willamette Basin in the Ruiter collection. This brings the confirmed number of microcaddisfly species in the Willamette Basin to 17, but additional species may be found with further efforts. By working together, we can learn more about the local species of these interesting aquatic insects and aim to maintain healthy populations.