In general, mealybugs are under good
biological control. That is, because of the presence of a number of predators
and parasites, this pest population is kept low. There are, however, a number of factors that
upset this balance. Two important factors are: the application of broad
spectrum insecticides (BSI) and ants.
The application of BSI will not only kill the target pest but “the good
bugs” as well. When this happens, the resurgence
of the pest can be worse than before. In addition, other pests, such as mites,
will become a threat because their enemies have been eliminated.
Ants also interfere with biological
control because they protect the pest from its enemies. By
controlling the ants, the mealybug population will eventually diminish as the
predators and parasites return. Although it takes time to work, even a couple of
months, baits can be effective in controlling the ants.
For a quick solution, mealybugs may
be sprayed with a soap and/or oil solution.
In addition, a high pressure stream of water from a garden hose will
dislodge many of the pests.
Added note: mealybugs have filaments,
or hairs around their body which protect them by repelling the spray droplets of insecticides. Consequently, a ‘spreader/sticker’ should be added to the spray solution. This
product acts like soap to break down the surface tension and allow the liquid
spray to spread out. Spreader/stickers
are necessary with most insecticidal applications but not when using
soap and/or oil sprays.
Photos by J.K.Clark, UCIPM
