Cotinis nitida
Phyllophaga rugosa
Look up June beetle in the English wikipedia. In Europe, it is a specific beetle closely related to the cockchafer, in de US the name is applied to a number of other species.
The scientific name of beetle is Coleoptera.
I haven't heard of a May Beetle but here in North Carolina we have a brown beetle that is called a "June Bug". They usually appear in the month of june.
The scientific or taxonomic name would be Cotinis nitida.
The scientific name of a darkling beetle is Tenebrionidae.
The scientific name of the African dung beetle larva is Scarabaeus lamarcki.
The scientific name for Japanese beetle is Popillia japonica.
The scientific name of a Bess beetle is Odontotaenius disjunctus.
The scientific name of the American carrion beetle is Necrophila americana.
The scientific name for the giraffe beetle is Trachelophorus giraffa.
June beetle, May beetle, May bug, green June beetle, figeater.