Plants affected
A wide range of indoor pot-grown plants, particularly those grown in relatively dry potting compost such as Pelargonium, cacti and succulents.
Symptoms
Root mealybugs are flattish, oval, sap-sucking insects that
are white in colour and up to 2mm in length. They secrete
a white waxy powder from their bodies, which often coats the
roots and soil particles around where the mealybugs are feeding.
Heavy infestations can cause plants to lack vigour.
Biology
This pest breeds throughout the year. All individuals are female, reproducing without the need for males. Eggs are laid in small clusters that are covered with a waxy powder. Immature nymphs are small versions of the adult insects.
Control
It can be difficult to eradicate this pest. If possible, cuttings should be taken of infested plants and the old plants and potting compost thrown away. When this is not possible treating pots with Bayer Provado Vine Weevil Killer 2 or Scotts Bug Clear Ultra Vine Weevil Killer - systemic insecticide compost drenches containing thiacloprid and acetamiprid respectively, may have some effect.
These pesticides are also effective against some sap-feeding insects, such as aphids and whitefly, and may also give some control against root mealybugs, as well as protecting the plants against vine weevil grubs.