This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
螠 combines 虫 (insect) with 益, which likely contributes the sound. The exact historical development is uncertain, and the character is rare.
The insect radical 虫 suggests a creature, but without a clear meaning, picture a rare bug whose name is written with 益 on the right.
For イ, imagine an insect that makes a tiny 'ee' sound: 'ee' -> イ, and the bug is written with 虫 and 益.