why must it be a flying one? Vine weevils will walk up the stems. What type of holes are you finding? leaves/fruits or both? could be slugs/snails depending on the damage. Could you add a photo?

I've ruled out slugs,snails caterpillars as I also have some lettuce and rocket at a lower level but these are left alone, only the tops of the chili plants are attacked over night,so much damage has been done that all flowers are killed before producing fruit, I have tried several of the bug sprays but to no effect

Have you tried covering them with fine netting or fleece overnight?

thanks for the suggestion of fleece or netting, its to late to save them this year but I'll remember in future