Chemicals emitted from a wild South American potato species repels aphids because it mimics the aphids' alarm pheromone.
"A wild species of South American potato discharges a message-chemical, a pheromone, which resembles that emitted by aphids when they are under attack. So those aphids never land on it." (Attenborough 1995:68)
Learn more about this functional adaptation.
- Attenborough, D. 1995. The Private Life of Plants: A Natural History of Plant Behavior. London: BBC Books. 320 p.
Cyndy Parr commented on an older version of Pheromone mimic repels aphids: South American potato:
This text refers to a wild species of South American potato and I have a feeling that is not nightshade. Unless EOL has a less desirable common name at the top.