What's eating my hibiscus?

Hibiscus rosa-sinensis grown as a houseplant or patio specimen is attacked by spider mites (especially in dry indoor air), aphids on new growth, whitefly on leaf undersides, and mealybugs in leaf axils. Outdoors in warm climates, Japanese beetles and thrips also damage flowers. Spider mites are the most persistent and damaging indoor threat.

Fine stippling on leaf surfaces, yellowing, and fine silk webbing on undersides and in stem forks; in severe cases leaves bronze and drop, leaving bare twiggy stems. Raise humidity by misting or placing on a pebble tray; wash off mites with a strong water spray; apply neem oil or insecticidal soap weekly; introduce Phytoseiulus persimilis predatory mites for persistent cases.

Tiny white flies erupt in a cloud when the plant is disturbed; nymphs on leaf undersides suck sap causing yellowing and sticky honeydew that leads to sooty mould. Use yellow sticky traps to monitor; apply insecticidal soap or pyrethrin spray to undersides of leaves repeatedly; ensure good ventilation around the plant.

White, cottony wax clusters in leaf axils, at stem junctions, and on new growth; heavy infestations cause wilting, stunted growth, and leaf drop. Dab individual colonies with a cotton swab dipped in 70% isopropyl alcohol; spray with neem oil; isolate the plant immediately to prevent spread to nearby plants.

Soft-bodied colonies cluster on tender new shoots and buds, causing curled, distorted growth and sticky honeydew deposits. Blast off with water; apply insecticidal soap; introduce ladybirds if growing outdoors; pinch off heavily colonised shoot tips.