Its a nightmare they destroy plant and fruit so quickly. What I normaly do is pick off the fruit they have got to. Bag it and bin it or burn. Cover with a very fine meshing from top to bottom,Weight the bottom down of the netting down. Could also try an eco spray or set a couple of sticky baits in the area. Hopefully thats some help. Nothing worse than cutting into a chilli and one of the larve is munching away in it