I'm with Steve... leave it alone; it will fix itself.

Don't prune. Citrus will push out new leaves at those empty nodes. Just monitor for any further insect damage, and once the tree can revive itself, it will push out new growth in those empty spots.

Thanks all, that's very helpful. I will pinch out the new growth at the ends of the branches as the plant is now becoming too wide, and leave it at that. Hopefully that will encourage more new shoots to fill in the bare areas too.

As is well known, deciduous fruit species need yearly cuts to promote new flush, flowering and crop. Citrus pruning is mainly devoted only to thinning and opening the canopy for light penetration as well as to keeping the canopy low. During the first years any pruning is discouraged, since research has shown that any cut to a young tree reduces root growth. This is due to the equilibrium between the foliage and root system. A plant is a biological unit. The only pruning on young trees should be to eliminate the central leader branch. In some weak growing citrus varieties, such as limes, satsumas, etc. it is not good make any cut at the beginning. After a few years, depending on the speed of tree growth, climate and cultural practices, a selective canopy thinning may be carried out.

I've always had a question on my mind about the proper way to treat a tree that has just recovered from a root issue. If a tree experiences extensive root death so that it has a hard time delivering enough nutrients to the rest of the tree, wouldn't there be a strain on the tree at that point (assuming the tree has recovered to a state where the roots are no longer being killed off)? I can imagine cases where a tree may have an extensive canopy that the remaining roots would have a hard time maintaining. Will the roots simply keep growing to a point were it can maintain the canopy, or would it be better at that point to reduce the canopy (via pruning) so the remaining roots can supply enough nutrients to maintain and even promote new growth in the canopy? Admittedly, I know very little on the subject matter and would love to know the science behind all of this to gain more of a mental picture. Ideally, I'd love to know the steps the citrus trees take in their root recovery process and how we can best help these trees.

Normally when there is root damage to a citrus tree, the tree is self pruning. A citrus tree is a unit. The tree wants to keep the scion and roots in balance. After root damage one soon begins to see die back in the scion.

I see, the citrus tree will actually kill portions of itself in order to self regulate. Are the leaves part of this process... ie it drops it leaves first then will start to dieback on the scions?

Tip pinching will not solve your problem.

It would make much more structural, long-term sense to wait until the last chance of frost has passed, and then make more significant but judicious cuts to the tree.

Josh