Mealy Bugs on a Cactus

Signs

• Mealy bugs are difficult to see between cactus spines, but growers can observe balls of white fluff on the cactus that indicate mealy bug presence. This white fluff may be on the cactus, on the pot or under the pot's rim. Mealy bugs produce a sticky honeydew that turns black if not removed and that attracts ants. Ants or a substance that resembles black mold mean you probably have mealy bugs.

Natural Control

• Spraying the plant with a 1:3 mixture of methyl alcohol (denatured alcohol) and water kills these bugs. Repeated use of fumigant smoke cones also drives the bugs away from the plant.

Chemical Control

• Texas A&M University recommends insecticides containing malathion or imidacloprid. Combine the insecticide with water, then use a paintbrush to dab the chemical solution onto the spiky cactus plant. Or look for insecticidal sprays designed to remove mealy bugs (consult the label for a list of pests affected).