My daughter’s 2-3yr old Salix tree is covered in ants. The aphids are all over the soft new tips of the branches and the ants seemed to be on top of them. Were they eating them do you think? Is there a difference between aphids and greenfly?
Ants do not eat greenflies. Ants ‘farm’ greenflies to take the sweet juice that greenflies pass out, called honeydew. Greenflies cannot digest all the sugars in plants and they pass out the sticky surplus, which ants gather to feed their brood.
The ant strokes the greenfly on the back, whereupon the greenfly produces a tiny droplet of honeydew which the ant sucks in and carries away.
Ants often move greenflies onto new shoots and plants, much as a farmer moves cows to new pasture. They also are known to remove the eggs and larvae of ladybirds, which eat greenflies, protecting their ‘livestock’.