Gardening jobs for the week: mealybug on houseplants

Compiled by the RHS Advisory Service - As seen in the Telegrah

Last Updated: 5:45PM GMT 15 Jan 2009

Mealybug on houseplants

Look for fluffy blobs, resembling cotton wool, in the leaf axils and other sheltered places on plants such as cacti and succulents, clivia, gardenia, Ficus benjamina, orchids (especially phalaenopsis), African violets, streptocarpus and citrus.

Do not mistake these for a fungal growth. These are mealybugs that feed on sap and cover themselves with a waxy substance for protection. Poke about and you will discover the pest beneath resembles a soft, pink or greyish white woodlice about 4 mm long.Spray with systemic insecticides containing imidacloprid (Provado Ultimate Bug Killer concentrate), thiacloprid (Provado Ultimate Bug Killer Ready To Use) or acetamiprid (Scotts Bug Clear Ultra concentrate or Bug Clear Ultra Gun).

Alternatively, use organic treatments including fatty acids (Bayer Organic
Pest Control, Greenfingers Organic Pest Spray) or plant oils or extracts (Growing Success Fruit & Veg Bug Killer, Vitax Organic 2 in 1 Pest and Disease Control), which can be used on edible plants.

Some plants may be sensitive to
the chemicals listed. Check instructions on the packet. If the reaction is unknown just treat a small area of the plant first.

Inspect roots of ailing cacti and succulents as they can be affected by root mealybug. If possible, take cuttings and discard the parent plant. If not, treating pots with systemic insecticides Bayer Provado Vine Weevil Killer 2 or Scotts Bug Clear Ultra Vine Weevil Killer may have some effect.