How To Control And Kill Mealybugs On Outdoor Plants & Trees
Infestations of mealybugs can cause some serious damage to plants in our landscape and gardens. Good thing is, mealybugs don't hide underneath leaves so they're easy to spot and identify. As you can see in the photo above, mealybugs appear on plants as tiny, soft-bodied insects surrounded by a fuzzy, white mess around the stems and leaf nodes.

Mealy bugs cause damage by sucking the juice from their host plants. Like many pests, they tend to favor new growth so you'll usually see them congregating at the tips of stems or twigs. Over time, their damage causes the leaves to yellow and eventually drop from the plant. They can also cause fruits, vegetables, and flower buds to prematurely drop off. In a bad infestation, their waxy excretions (also known as honeydew) encourages the development of sooty mold fungus.

How To Control Mealy Bugs

If you see mealy bugs on your plants, there are several control options:

Wash them away. Mealy bugs can be dislodged with a steady stream of water. Repeat the treatment as necessary. This is best for light infestations.

Neem oil for outdoor plants. Neem oil is an organic oil derived from the neem tree. Use according to label instructions. In addition to its insecticidal properties, neem is also a fungicide and has systemic benefits (meaning the plant absorbs it so it can control insects it doesn't directly contact). According to the Environmental Protection Association, neem is safe for use on vegetables and food plants as well as ornamentals. 

Note: To avoid harming beneficial pollinating insects, I recommend spraying any insecticide in the early morning or late evening hours when beneficial pollinating insects are not active.

Insecticidal soap for indoor houseplants. Insecticidal soaps are available in the marketplace, or you can make your own by using a dish detergent such as Ivory Liquid. Try to find a product free of perfumes and additives that might harm plants. Mix the soap in a weak concentration with water (starting at 1 teaspoon per gallon and increasing as necessary). Spray on plants.