Mealybugs: how to spot, prevent and treat them pest

How do you spot mealybugs?

Flecks of white waxy wool in the leaf axils, along the leaf sheaths and in other sheltered corners of the plant. Under them sit soft pink bugs and orange eggs. The plant is sticky with honeydew, black sooty mould grows over the leaves, growth stalls and the leaves may drop early. Some species live on the roots and show up only at repotting.

How do you prevent mealybugs?

The females neither fly nor walk far, so you nearly always bring them in with a new plant: check the leaf axils when you buy and keep a new plant apart from the collection for a while. Clear away dead leaves and prunings as they appear, because the eggs are on them. A plant will take a few mealybugs. A badly infested one is often cheaper to throw away than to rescue. In a greenhouse the predators hold them down, the ladybird Cryptolaemus and parasitic wasps, which work in the warm half of the year.

What works against mealybugs?

The waxy coat repels the spray, so potassium soap has to reach exactly the leaf axils where the bugs sit, and a single application is rarely enough. Single nests are easiest to take off with a cotton bud.

Check the registration and the label before use.

Which plants get mealybugs? 15

Fruit trees 7

Ornamentals 1

Houseplants 7