Welcome to day two of Aquatic Week!

March 30, 2020

Welcome to day two of Aquatic Week! This week, we're highlighting the various critters that you can find in creeks and ponds in southwest Virginia. At first glance, these photos might look like I just found some twigs that got stuck together ... and that's exactly what the caddisfly wants you to think. Caddisflies (order Trichoptera) are a large group of insects that spend their larval stage underwater. As adults they resemble small moths, and with good reason; they're closely related to moths and butterflies. The adults are also known as "sedgeflies," and most fly fishermen probably have a few flies in their tackle box designed to resemble adult caddisflies. Within the order Trichoptera, there are two suborders: Integripalpia and Annulipalpia. Annulipalpia larvae produce silk and create a fixed cocoon-like structure; they hide inside this structure and wait for food to float past the opening. Integripalpia (of which the pictured caddisfly larva is a member) are go-getters; they spin a silk casing and carry it around with them, often attaching sticks, leaves, grains of sand and other debris to the casing to help it blend in to the surrounding stream bed. Caddisfly larva don't just grab anything they see to incorporate into their mobile homes, however; the specific types of debris they attach to their silk cases are determined by their genetic makeup, meaning that you can identify a caddisfly larva down to its family or even genus just based on the construction of its protective casing. If you're poking around in your nearest creek and you find a bunch of caddisflies, consider it a good sign. They're sensitive to water pollution, so if you can find caddisflies, chances are good that you have a healthy creek. #BenInNature

About this post: Social distancing can be difficult, but the next few weeks present a great opportunity to become reacquainted with nature. While he is working from home, Administrator of Science Ben Williams is venturing outdoors each day to record a snapshot of the unique sights that can be found in the natural world.

This post brought to you by VMNH Corporate Partner S & K Office Products, Inc.