What's eating my athyrium filix-femina 'frizelliae'?

The tatting fern 'Frizelliae' has distinctive bead-like pinnae that make slug damage especially conspicuous — these delicate fronds are the plant's chief vulnerability in the garden. Vine weevil grubs threaten container roots. Aphids and caterpillars occasionally target new growth. Deer may browse when food is scarce.

Individual bead-like pinnae eaten away, leaving skeletal midribs; new croziers consumed entirely Ferric phosphate pellets around base; hand-pick at night; avoid thick mulch that harbors slugs

Notched frond margins from adult beetles; C-shaped larvae destroy roots causing sudden wilting Apply Steinernema kraussei nematodes in late summer to moist compost

Portions of fronds eaten from the margin inward; feeding typically at night Hand-pick caterpillars; apply Bacillus thuringiensis (Bt) spray as a biological control