Mealy bugs are also known as wooly aphids or cochineal insects. They are a sucking insect which multiply rapidly and can easily suck a small cactus or
succulent plant dry. They can be recoginised by the whilte waxy wool that they produce. Individual insects are about 0.1 inch (3mm) long.
There are many different varieties of wooly aphids, some varietes attack the roots of the plants rather than their stems and the first signs of this variety may be that
the plant stops growly, looks sickly and starts to shrivel. The best trearment for mealy bug is a systemic insecticide which poisons the insects when they suck the
sap of the plant. If a contact insecticide is used it must contain a strong wetting agent to break down the insects waxy coat.
Red Spider Mite
Red spider mites are very tiny (0.01 inch - 0.3mm) and often the first that is noticed of the pest is that the surface of the plant turns from green to a dull brown as the tissue is damaged.
Only certain genera seem to be susceptible to these pests. Rebutia, some species of Coryphantha (and related plants) and Melocacti are amongst the most
vunerable. A variety of succulent genera are also attacked although it may not be the same species of red spider mite which is the culprit. Plants are particularly susceptible
when grown in a greenhouse with little air movement, so good ventilation is important. The insects can be killed with a systemic insecticide, but they are quite resistant and
several treatments may be required.
This is page of the Cactus and Succulent Plant Mall maintained by Tony Mace (firstname.lastname@example.org)