The close relationship between the katipō and redback is shown when mating. A male redback is able to successfully mate with a female katipō producing hybrid offspring. However, a male katipō cannot mate with the female redback as the male katipō is heavier than the male redback, and when it approaches the web it triggers a predatory response in the female leading to the male being eaten before mating occurs. There is evidence of interbreeding between katipō and redbacks in the wild.