In Digimon, every beetle-based partner Digimon (excluding the random kids from the Digimon World Tour) is lightning based. i.e. Tentomon and his evolutions, Beetlemon and his evolutions, and Ballistamon.
It's not just Digimon though, in Power Rangers Ninja Storm (the best one) the 2 beetle rangers were officially known as the "Thunder Rangers" and in Pokemon the new-ish Vikavolt and Charjabug are electric-based beetles too. I also remember I used to watch this show called Ultraman (it has basically the same premise as Evangelion before it got deep) when I was little and whenever there was a beetle kaiju he would throw lightning at people. There's also a show called Beetleborgs which is just Power Rangers with beetles and they're almost all lightning based (but I don't know if this was a Japanese or American show).
I tried to google if it was some old myth but the only results were Egyptian, Hebrew, and Native American mythology.