Soldier aphids go cuckoo

Aphids hold a special place in the study of social evolution, because they include the only eusocial animals that are clonal. We might expect social aphid colonies, if they consist of pure clones, to be free from reproductive conflict. A fascinating new study by Abbot and colleagues shows that there can be high levels of clonal mixing within colonies of a social aphid. The intruding aphids cheat on the host clone by not helping in gall defence and instead invest singlemindedly in growth and reproduction. Now that aphid soldiers have been shown to cheat, as well as to defend, clean and repair their galls, it is perhaps time to admit them ungrudgingly to the elite cadre of the truly social insects.