How many kinds of cicadas are there? That depends on what you mean by kinds.
There are over 190 species in the U.S.A. and over a dozen in Canada. Australia has hundreds of cicadas and you can find a list of them here.
World wide, there are over 3,390 species, with new species described every year (I counted them all in this book)!
A good source of papers about new cicadas is Zootaxa.
This year I heard one or two Magicicadas in our yard in May, and the usual yearly cicadas started singing in June which is VERY early! What’s going on?
Thank you for counting them! Very useful number. That is more than I had thought were described.