>The queen almost certainly has to use her stinger when she exits her cocoon: to kill ther other queens

I think this is one of the more interesting differences. Plenty of species operate in groups. But its usually a dominant male with a harem. Bees and the like are unusual in that it's a dominant female.

I think it's related to the ease of reproduction. The females put relatively little into their off spring compared to a lion or even birds. It lets them to be essentially autonomous in reproduction which allows them to create offspring that are more like limbs.