I hadn't read the Flowerdew advice, but I had let the last plant in the row grow on, it's only ever sprue, I think because it is too close to an inadvertent oak sapling (dang those squirrels and their acorn-burying....). That fern has had the fewest beetles of all, while the sturdy, healthy fat spears further along are crawling with the beasties. Having said that, with a cold wet morning there were none at all to catch yet today!