This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
蝤 combines 虫 (insect) with 酋, which likely contributes sound. The exact historical development is uncertain.
The insect radical 虫 suggests a bug, but the overall meaning is unclear. Picture a mysterious insect hiding inside a jar (酋).
For シュウ, imagine a shoe (シュウ) with a strange insect inside it: shoe -> シュウ, and the bug is the unknown 蝤.