Aphids with Attitude
An army of real-life adolescent clones
By Susan Milius
It’s not often that Arnold Schwarzenegger gets compared to an aphid. An ant, maybe–many ants spend all day lifting heavy weights and defending the homeland. Unlike ants, bees, or Hollywood heroes, most of the world’s 4,000 or so aphid species aren’t by any stretch of the definition self-sacrificing social animals. Most aphids spend their lives as independent, pinhead-scale, six-legged versions of cows. They’re specialized for grazing but not much else–high throughput, low drama.
Yet a few aphid species turn out to be more like killer bees than like cows. These aphids live together in colonies, each founded by a highly fertile, queenlike female. While her daughters are still adolescents, they grow the outsized fighting legs that earned them a favorable comparison to Schwarzenegger in a scientific journal.