The description of zero divisors in monoid of semigroup varieties under wreath product

It follows from the author's results published in 1999 that the wreath product of any two overcommutative semigroup varieties coincides with the variety S of all semigroups and S is the zero of the monoid MV of all semigroup varieties under the wreath product of varieties. In this paper, we give a full description of all cases under which the wreath product of two semigroup varieties equals S.