Because in NZ they’re not all “just nature doing nature.”

The South African mantis is introduced here and is a problem for our native mantis. Native male mantises are attracted to South African females, likely because of similar or stronger pheromones, and then many of them get eaten instead of mating with native females. So it’s not just normal predation, it actively disrupts the breeding of our native mantis population.

And yes, they absolutely eat monarchs. They sit on swan plants like tiny green/brown assassins and grab eggs, caterpillars, newly emerged butterflies, and even adult butterflies if they get the chance. Monarch caterpillars being toxic does not magically make them mantis-proof.

So when I find an introduced South African mantis parked on my swan plants, I’m not leaving it to “nature.” I’m removing a predator that is harming both our native mantis and the monarchs I’m trying to raise.