Help please.
I sprayed my leeks with a chrysantheum concentrate up until October and they didn't seem to have been attacked by anything. Harvesting them today I found a few tiny brown pests and small grooves on the inside of the plants. Are these leek moth or leaf mining fly grubs? If so is it worth spraying them again at this late stage? Or is there anything else I can do?
(see attached photos)
Thanks in advance for your advice.
Anton