There are no such things as "Green Ladybugs".
Even the observant among us are bombarded with objects and experiences that we don't quite understand, and so we file them away in convenient niches. When I was a child, I noticed that some ladybugs were red, and some were green. What was the difference, I wondered? I never really got an answer, and for decades it laid in a dusty little cubby in the filing cabinet of my mind, until I recently found out the answer.
"The Green Ladybug" is a type of Cucumber Beetle, namely the "Spotted Cucumber Beetle", Diabrotica undecimpunctata. It superficially looks like a ladybug, being about the same size, with the same general rounded shape, and the same spotted carapace. Inside of the taxonomy of beetles, they are not closely related, but to the layperson, the Spotted Cucumber Beetle looks exactly like a ladybug with a green shell. There is a gigantic functional difference though: the ladybug is a predator that is generally considered beneficial due to its habit of eating aphids and other pests, the spotted cucumber beetle is a herbivore that grazes on garden vegetables, sometimes with very negative results. Thus, while it superficially looks like a ladybug, a spotted cucumber beetle is something else entirely.
As a final note, the Latin species name, "undecimpunctata" means "eleven spotted". The cucumber beetle has 12 spots when the wings are spread, but when they are together, the top two touch, making 10 small spots and 1 bigger one, thus, "eleven spotted".