Ants, bees, and wasps operate on a genetic system called haplodiploidy. It works like this.

Queens don't actually mate to produce male offspring.

Females are Diploid: They are created from a fertilized egg. They have two sets of chromosomes - one set from the mother (the queen) and one from the father's sperm, which the queen releases from the spermatheca when she wants a female.

Males are Haploid: They are created from an unfertilized egg. They have only one set of chromosomes from the queen located in the nucleas of the egg. The queen does not release the male's sperm when she wants a male offspring. They have no father. They hatch from an egg that contains only the mother's genetic material, meaning they are essentially a haploid (single chromosome set) version of the queen.

The M. ibiricus queen produces 2 kinds of offspring with the M. structor:

Sterile Female Hybrid Workers: These are produced in the standard way. The queen lays an egg (containing her genes) and fertilizes it with the sperm from the M. structor male. The resulting worker has DNA from both parents. It's a true hybrid. There is no "dominance"; it's a merger of two different species' DNA.

Fertile Male M.structor Clones: This is where things get really bizzare.

Remember that in the normal case:

- The queen does not use a male's sperm to produce male offspring.

- Joining both DNA always results in a female (males do not have two sets of chromosomes)

There can only be one conclusion. The queen creates this special clone from the male's DNA only, probably by somehow purging her DNA from the nucleus of her egg.