UV2 Baetis Nymph- This nymph is a great representation of Baetidae. Baetidae (Blue Winged Olives) is a family of mayflies with nearly 1000 described species distributed worldwide. These are among the smallest of mayflies, adults rarely exceeding 10 mm in length excluding the two long slender tails and sometimes much smaller. This pattern works great on spooky fish (like on the South Holston) since there is no extra flash of a beadhead. UV enhanced.