[noselasd]

I thought one of the big points was there's no M. structor females on the islands.

[Amezarak]

They've extended their range, so there's lots of cases where they don't have wild ones around, but there's still overlap, at least according to the article I read.

[noselasd]

Yes, in some areas - but not e.g. on Sicily. https://www.youtube.com/watch?v=Z-O4_AwWpfI gives perhaps a better overview

M. Ibericus produces 4 kinds of offsprings.

    1. M. Ibericus queen + no male (unfertilized egg) -> M. Ibericus male.
    2. M. Ibericus queen + M. Ibericus male -> M. Ibericus queen
    3. M. Ibericus queen + M. Structor male -> M. Structor male, no genes from the mother
    4. M. Ibericus queen + M. Structor male -> M. Structor/Ibericus hybrid female, (worker ant, infertile)