Bugs on my fruit trees

Market Boy

Hi Gardeners. I have an Apple - Vic Plum and Pear Tree all net to each other.
Both the Apple and Plum have a lot of curled up leaves. When you un-curl the leaf on the apple you can see loads of tiny grey bugs. When you do the same on the plum there is a black mess with a few tiny grey bugs. Some of the leaves seem eaten but I cannot find any caterpillars. The pear tree is totally uninfected and is in rude health.
Any ideas what these could be and how best to treat the trees. I am not totally organic. 

BobTheGardener

They sound like aphids, which are 'farmed' by ants who feed on their sugary.. erm.. excrement.  You will probably find ants running up and down the trunks of the affected trees, often carrying baby aphids to fresh growth tips, where they cause damage.  You can use a spray attachment on a hose to knock them off, or a hand sprayer with a drop or two of washing-up liquid (ideally, horticultural liquid soap) mixed in the water, which will drown them.  If you can stop the ants climbing up the trunk by using a grease band, the problem will go away almost completely.

mrtjforman

bug clear ultra is the most effective against aphids but I find it is a sign of the tree being weak. I haven't bothered spraying one of my cherry trees again this year after the aphids have reinfested it because i know it desperately needs to be repotted with fresh soil.

So I'd recommend fertilizing the soil with some fish blood and bone meal or manure and use the ultra gun to kill the aphids.

Market Boy

Thanks for that info. I will try the washing up spray. Put a grease band round the trees
and feed them. Hopefully should all work together. If not I will resort to the Bug Clear Ultra.