They do scurry....they run around the shoot as you approach, and drop to the ground to hide.....but you have to squish them, or their eggs (cunningly pushed horizontally into the stems) will hatch into ravenous grubs that will strip the fern in a day o two.
At the moment we are all harvesting our mature asparagus so the beetles and eggs have nowhere to go. The people who have to look out are those who are patiently waiting for a couple of years for their asparagus to mature, so the fern develops early and the beetle grubs eat it.