Help, please. Dying leaves on plant - is it due to bug?

I have a geranium 'johnson's blue' - that has leaves that are curling up and have black spots on them. I think it must be due to a bug? Next to this, I just replanted (it died over the winter - maybe due to same problem? carypoteris - that is now also showing the same symptoms. Lastly, in the same portion of the bed, I have a salix integra - hakiro nishiki - that is dying. I didn't think that would pull through the winter, but it did. It partly leafed out and now is dying.
What do I need to do to save these plants?

Get rid of the bug.

The bug in the photo looks like a Harlequin Bug.
Try using a systemic insecticide.

Im not so sure its due to bugs,sounds to me that it could be down to soil conditions in that area,the only thing I would suggest is that you move the plants (if possible) to a different patch of the garden and see what develops ....something is not right here,too much involved for it to be bugs ....

Have you looked inside the curled part to see if there is a bug in there?

Initially I thought I saw little bugs on the plant, but they are gone now. I can't really move the plants from this bed - it's raised and I added soil a few years ago to it. I could add fertilizer...? What's a harlequin bug?

did you see the bug in your picture?

Well, when I took the picture I did... LOL I haven't really seen more - Just looked and no - and the leaves are heavily spotted. I didn't see any bugs now at all - although I did just scare a rabbit.

oooh, maybe you have a rabbit hole under there somewhere,
you mentioned black spot, maybe you have a fungus / mold

So I should look for a systemic insecticide and a fungicide?

I had those same bugs in your picture wreak havoc on my pepper plant leaves and some select flowers. If you watch them they stick a sucker into the leaves which then results in a serious of small brown to black dots on the leaves. The leaves shrivel and die. I removed all the significantly effected leaves and sprayed with Bonide Rotenone And Pyrethrum Spray, which seems to have done the trick.

Ick! I Have to agree with the bug theory. Best bet is to remove them and remove the infected leaves then see what happens. Also as EtoileduNorde mentioned, sprays can come in handy if you don't want to pick bugs off...ick!