I found these today on my willow tree, should I be concerned, and what can i do to solve the problem? Also ants are running up and down the tree.
You have a few things going on there, red. The top right is aphids and the ants are farming them. They won't do much harm unless you get a great many. If you do, you can spray the affected bits with water to which you have added a few drops of washing up liquid. The bottom right are eggs of a butterfly or moth, I think. Again, they shouldn't do much harm. If you are worried you can remove some by rubbing them away with your fingers. There are sprays to kill the caterpillars but I would avoid these myself.
Thank you so much Posy, do you have any idea what the orange is on the leaves?
Those look like ladybird eggs ....... don't destroy them. The larvae will hatch out and eat your aphids ... that's why the ladybirds have laid them there
Thank you Dovefromabove, the tree is very young should I be concerned about the orange stuff?
Thank you Dovefromabove I just checked out your link. ?
It's a tree ... trees have the occasional discoloured leaf for a variety of reasons ... I don't worry about the odd few ... only if the ground beneath the tree starts getting covered with them as if it was autumn.
Especially don't worry about a willow ....... willows are as tough as old boots - with the exception of that pink leaved 'Flamingo' which I think is an aberration (sorry to those of you who like it ).
And the round thing on the top-left photo is probably a gall. An insect (usually a tiny wasp) laid an egg in the leaf vein and the larva released a hormone which caused the tree to produce growth around it. The young larvae use these as a home while they grow. It's not really detrimental to the tree. The way these interactions occur between insects and plants is fascinating!
Thank you Dovefromabove and Bobthegardener that is a huge help