What's eating my bougainvillea spectabilis?

Bougainvillea spectabilis, whether grown outdoors in warm climates or under glass, is most troubled by bougainvillea loopers (caterpillars that strip bracts and leaves) and aphids on new growth. Mealybugs cluster in stem joints; scale appears on older wood. Indoors or in conservatories, spider mites and whitefly are also common. Prompt detection prevents rapid defoliation by loopers.

Larvae eat through bracts and leaf tissue rapidly, leaving ragged holes or completely stripped stems; damage can be severe within days. Hand-pick larvae and eggs daily; spray Bacillus thuringiensis (Bt) on young caterpillars; use pyrethrin spray for heavier infestations; check nightly as adults are moths.

Dense colonies on new shoot tips and flower bracts; distorted, sticky, blackened growth; particularly bad on plants with lush nitrogen-fed growth. Knock off with a strong water jet; spray insecticidal soap or neem oil; introduce lacewings or ladybirds outdoors; reduce nitrogen fertiliser.

White cottony masses accumulate in stem joints and leaf axils; sap-sucking weakens growth and deposits honeydew causing sooty mould. Dab colonies with alcohol-soaked cotton bud; spray neem oil or insecticidal soap thoroughly into joints; use systemic insecticide for severe infestations under glass.

Clouds of tiny white insects on leaf undersides; nymph feeding causes yellowing and leaf drop; honeydew promotes sooty mould — common in conservatories. Hang yellow sticky traps; spray leaf undersides with insecticidal soap or neem oil every 5–7 days; introduce Encarsia formosa under glass for biological control.