What's eating my ruellia devosiana?

Ruellia devosiana, a low-growing tropical Acanthaceae houseplant with patterned leaves, is most challenged by spider mites in warm, low-humidity conditions. Mealybugs can lurk along stems, and aphids may appear on tender new growth. Keep humidity elevated and inspect the undersides of leaves every week or two.

Tiny pale dots on leaf surfaces; webbing beneath leaves; foliage yellows and shrivels in severe cases Mist foliage and set on a pebble-and-water humidity tray; spray neem oil or insecticidal soap every 7 days; remove webbed leaves

Fluffy white wax at node junctions; honeydew and black sooty mould on stems and lower leaves Remove with alcohol swabs; apply insecticidal soap spray to all surfaces; follow up weekly for a month

Soft insects on fresh shoot tips; curling, distorted young leaves and sticky residue Wash off under a gentle tap; apply neem oil or insecticidal soap; repeat as needed