What's eating my blue-stemmed polypody?

Blue-stemmed Polypody (Polypodium subpetiolatum) is a less common houseplant fern susceptible to the typical indoor pest trio: scale insects on rhizomes and stems, mealybugs in growth junctions, and spider mites in dry conditions. Keeping humidity above 50% and inspecting the creeping rhizomes regularly prevents serious infestations from taking hold.

Brown or buff-coloured shells attached to rhizomes and frond undersides; honeydew and discolouration Remove manually with alcohol-dipped swabs or a soft brush; apply horticultural oil or insecticidal soap every 2 weeks

White woolly deposits at stem joints and rhizome forks; slow growth and sticky residue Dab with isopropyl alcohol; spray diluted neem oil over the whole plant every 7–10 days for 4 weeks

Stippled, dull fronds with fine webbing on undersides; fronds yellow and drop in heavy infestations Raise humidity, shower fronds clean, and treat with insecticidal soap or neem oil weekly until resolved