きょびちゅうじゃなかったです
挙尾虫じゃなかったです
kyobichūjanakattadesu

Noun
Desu Copula

The polite, past negative form of しりあげむし

1. Wasn't a mayfly.; Wasn't a mayfly larva.

Past/Perfective
Negative
Polite
Casual Register
Usually Written in Kana