Question:
Some the leaves of our Yew Pines have a white fluffy, cotton-like material on them while others are very sticky and covered with black mold. I’ve been unsuccessful in washing the foliage off and spraying it with soapy water. What is it and how do I get rid of it?Answer:
- Your Yew Pines, Podocarpus macrophilia, are infected with Mealybugs. Mealybug is a worldwide pest on plants grown both in and outdoors.
- In the Bay Area, it poses little problems except with African Violets, orchids, cactus, some indoor foliage plants and Podocarpus. It is not to be confused with Woolly Apple Aphid that attacked pyracantha, cotoneaster, and apple trees.
- The white threads/filaments protect the insect and looks like cotton candy on a stick. There are many different species of Mealybugs.
- The female is a soft-bodied insect, gray with an oval shape and up to one-eighth of an inch long. A white fluffy, waxy material covers some species.
- Also, they’re wingless and move from one host to another by crawling.
- The female lies from two to six hundred eggs while others species give birth to living young. The male is small, has wings and a long waxy tail.
- Mealybugs are found in the leaf crevices at the base of the stems or petioles of plants with long leaves like the Podocarpus.
- They’re a sucking insect that feeds on the leaves extracting the plant juices, producing a clear, sticky residue or Honeydew.
- A black mold then forms on the residue. You may find a steady stream of ants running up and down the main trunk as they use the Honeydew is a food source.
- There are many controls available for Mealybug; however, they require repeat applications.
- On houseplants, Mealybug can be controlled using a cotton swab dipped in rubbing alcohol or a solution of Insecticidal Soap.
- With Podocarpus, I’d use the Bayer Advanced Tree and Shrub Protect and Feed as it controls a wide range of insect pests including Mealybug in landscape trees and shrubs, even those in containers.
- It has a distinct advantage over other solutions as it’s applied annually, and not sprayed on the foliage. The insecticide and fertilizer combination is applied to the soil where it is absorbed by the roots when water is applied.
- Once absorbed, it moves up through the plant providing yearlong protection. It will even translocate into the new growth after the initial application. It will take about a week to ten days to work its way up your podocarpus.
- With large shade trees, it takes up to three months to reach the top. The amount required is determined by the diameter of the main stem or stems with multiple trunk plants. The label has all the specifics. The fertilizer is essential, as it encourages the new growth, which covers or masks the unsightly existing foliage; otherwise, the black mold slowly disappears over time.
- The Bayer Advanced Tree and Shrub Protect and Feed solution is a simple, one step answer to controlling Mealybug.