worm-eaten, conch
蠡 centers on the idea of being eaten away by worms or insects, leaving something hollow or damaged. The conch sense likely extends from the hollow, worm-eaten appearance of a shell.
蠡 combines 彖 (a pig-like animal) with 䖵 (two insects). The exact historical development is uncertain, but it likely expresses the idea of insects eating away at something, possibly a gourd or shell, leading to the meanings of worm-eaten and conch.
Picture two insects (䖵) crawling over a pig-like shape (彖), eating away at it until only a hollow shell remains. That hollow, worm-eaten shell is a conch.
For レイ, imagine a ray of light shining into the hollow, worm-eaten conch: ray -> レイ, revealing the damage inside.