How to Get Rid of Mealybugs on Bamboo
Mealybugs are less than 1/2 inch long, but an infestation can significantly damage your bamboo plants. The pest sucks the juices from the bamboo culms, or hollow shafts, and can cause culms to become deformed or stop growing in some cases. Mealybugs may not always be apparent from looking at your bamboo, but peer inside the hollow tubes and you may find the pests hiding. You can get rid of mealybugs in a variety of ways.
Pick off the random mealybug or two that may be present on your bamboo plant. In the event of a light infestation, you might never even see the bug but may notice evidence of its presence, a white cottony webbing on the plant. Remove all debris by hand.
Drown mealybugs to kill off a moderate-to-severe infestation without resorting to chemical means. According to the American Bamboo Society, or ABS, many varieties of bamboo are indigenous to wet regions of the world and can withstand a good water dunking. Place the pot in a bucket of water and leave it for between 12 and 24 hours.
Apply biological controls to eliminate your mealybug problem. A type of ladybug, appropriately named the mealybug destroyer, as well as lacewings, like to eat the pest. The amount of a beneficial species required will vary, according to the severity of your infestation. Once you've purchased the mealybug eaters from your local garden center, let them loose on or near your bamboo.
Manage destructive mealybugs with chemical controls that will kill the pests without harming your bamboo plants. A contact product that contains dimethoate or dinotefuran can be injected directly into the culms of the plant, or sprayed on the surface. ABS's "Bamboo Magazine" suggests mixing the chemicals with dish detergent to facilitate removal of the mealybug webbing.
Examine your bamboo on a regular basis after you've treated with chemical insecticides. Mealybugs that hadn't yet hatched at the time of the initial treatment may still be lurking, and will require a follow-up spraying.