As far as humans are concerned, sexually-transmitted infections are things to avoid. But imagine if these infections didn’t cause death and disease, but gave you superpowers instead. It may sound like a bizarre fantasy, but it’s just part of life for aphids.

Aphids mostly reproduce without sex, giving rise to many all-female generations that are exact copies (clones) of their parents. They only have sex once in autumn, the only time when mothers give birth to males. Asexual reproduction makes sense for aphid mothers since they pass on all of their genes to their daughters. If they reproduced sexually, their offspring would only inherit half of their genes, diminishing their legacy. Why then would a female aphid choose to have sex