Mealybug Control

December 14, 2008 Ben Garden

In the summer when its nice and warm with an increase in humidity Mealybugs begin to cluster on new shoots of plants.

Mealybug females feed on plant sap. They attach themselves to the plant and secrete a powdery wax layer which is used for protection while they suck the plant juices. This waxy layer protects the bugs from water and pyrethrum based insecticides.

The life cycle of a mealybug is based on the temperature. Most mealybugs have numerous, often overlapping, generations each year. Like all insects, their development is dependent on temperature, if the temperature is too low development can cease totally or is slowed to a greater or lesser degree, as if it gets too warm the reproduction is slowed.

Biological Control can be achieved by releasing parasitic wasps such as Leptomastix dactylopii and Anagyrus fusciventris into the infested area. The wasps lay their eggs into young mealybugs, on hatching, the wasp larvae feed on the internal fluids of the mealybugs.

A dose of White Oil will give good control over mealybugs, the oil breaks down the wax layer and suffocates the bug as it sucks the sap from the plant. Care needs to be taken in warm weather when plants can be affected by heat. It is best to spray with white oil at night, then hose off the oil in the morning.

Imidacloprid is another chemical which will kill mealybugs on contact, it is also a systemic chemical (is absorbed by the plant and kills other sap suckers). While it is not organic, the application does not need to be as thorough to kill off all of the population.

Ants are the number one cause of mealybug spread. The mealybugs excrete a sweet juice which ants love to collect and eat, in the process they collect baby mealybugs and their eggs and move them around your garden. Some form of ant control will reduce the spread of mealybugs.

Happy mealybug hunting!

bugs, insect control, mealybug, white oil