i believe this is a lemon mint. i have it for two weeks and when it came it was in exactly the same condition as it is now except that it had two times more leaves. plant from the start looked bad but i accepted it in the shop they said it needed repotting so i did it maybe the very next day, its roots really started to destroy old pot. id didn't completely change soil, just added as needed to fill new pot i keep it on the eastern window. it's spring now, temperatures are moderate. i water it when it starts to loose moisture, at the moment it's once every 4-5 days. every sunny morning i spray it... there were two caterpillars but they are no more... so what is this "black thing" over leaves? they're getting dry and drop on the first touch except caterpillars i saw no bugs of any kind what should i do? whats's the problem?
