Sigh....this has been a good year for asparagus production until suddenly the tips of spears were chewed off. The cuts look ragged, like either teeth of some sort or gradual whittling by perhaps a bird. In one case I found the spear tip on the ground by the emerging stalk. Even very thin tall stalks (perhaps 12-14") don't escape. But only the tips are removed.

Truthfully, we've had our fill of asparagus already but what concerns me is the damage to emerging smaller spears which will impact on foliage growth and next year's crop. NOTHING else in the garden is touched. I have broccoli, lettuce, chard, kale, peas, spinach, kohlrabi...etc. No damage on anything else. No signs of digging.

I've covered closely spaced emerging spears with little cages just lightly staked into the ground. That works but is impractical if I want top growth. So whatever it is, it isn't strongly aggressive--the cages could be fairly easily knocked over.

Any ideas? I've grown asparagus for years and this is the first time I've ever had this problem.