It seems that what Marx called socialism is basically communism.
By 1888, Marxists employed socialism in place of communism as the latter had come to be considered an old-fashioned synonym for socialism. It was not until after the Bolshevik Revolution that socialism was appropriated by Vladimir Lenin to mean a stage between capitalism and communism.
Many people (including me) would say that there isn't any meaningful difference between the two, whether we are talking about Marx's time or any time since. I don't know whether Wilson thought there was any meaningful difference between the two; as far as I know nobody asked him.
The two terms were more or less synonymous when Marx wrote. Later ideologues have attempted to differentiate them; whether or not they have succeeded is a matter of opinion.
Wilson specifically used the term "socialism". The full quote is given here:
https://en.wikipedia.org/wiki/E._O._Wilson#The_Ants,_1990