Posted: 15/05/2013 at 21:52
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"my 3yr old crab apple tree is covered in these eggs but no eggs on other fruit trees By steve marie2"
Hi Steve, those are not eggs, but some kind of aphid. There's some RHS advice on aphids here:
As the tree is probably still quite small, you can probably kill the aphids by spraying with water containing a small amount of washing-up liquid (this will drown them.) Or use a proprietry insecticide which says it kills aphids on the label, if you prefer.
Have a look to see if there are any ants running about the tree. Ants 'farm' aphids and feed off the sugary liquid they exude. The ants carry the aphids around the tree to fresh new growth. If you put a thick ring of vaseline or similar all the way around the trunk of the tree, it should stop the ants climbing up and doing this.