Most likely caterpillar damage at some point. Check the leaves regularly and ensure your plant is growing in optimum conditions. Not sure why your plant has a stake with sticky tape on. I suggest you undo the tie and if you need to train it a certain way, use twine instead. The branches need good air flow.
I have a Tahiti Lime bush and a couple of years ago it was attacked by the caterpillars of the light brown apple moth (which is a known problem pest for citrus trees). So it would be worth going over your plants looking for eggs and wipe them off.
Bee x
Gardener and beekeeper in beautiful Scottish Borders
A single bee creates just one twelfth of a teaspoon of honey in her lifetime
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I have a Tahiti Lime bush and a couple of years ago it was attacked by the caterpillars of the light brown apple moth (which is a known problem pest for citrus trees).
So it would be worth going over your plants looking for eggs and wipe them off.
Bee x
A single bee creates just one twelfth of a teaspoon of honey in her lifetime