Lychee problem

I fond a lychee seed rooting in my food disposal box, so planted it. It took a while for a pair of leaves to survive and grow large. The first few withered before they were recognisable as leaves. The first pair were large when a second pair opened and grew. (first picture),

However now one of them is showing signs of being eaten from within. The hole is getting visibly bigger everyday.(second picture).

Any ideas what is causing the  leaf damage and anyone got any expertise in growing lychees from seed that they could share with me.