These calls all involve homeowners who have noticed small bumps on the stems of their tree and a sticky substance on the tree and ground.
Some homeowners have described this substance as tar; however, it is not tar. Instead, that substance is "honeydew," while the bumps are a type of insect. The insect that is impacting the tulip tree is "tulip tree s-cale."
There are more than 60 different kinds of scale insects that impact Indiana shade trees and shrubs. Often, scale insects are overlooked or ignored until the tree or shrub starts to die with no warning. There are two district types of scale insects that can be determined based on their behavior. The first type of scale insect is called armored scale. Armored scale insects do not produce honeydew. Honeydew is a sugary liquid that is a nuisance to homeowners. Instead, they have a straw-like mouth that moves around bursting plant cells as it feeds off of their contents.
The second type of scale insect is a soft scale. Soft scale insects produce honeydew. Not only is honeydew a nuisance, it is also a threat to plant health as it attracts ants, flies and wasps and is a food for a black fungus called sooty mold. Sooty mold will shade leaves, ultimately reducing plant growth.
Scale insects spend the majority of their life feeding on one specific part of the tree since they are unable to move.
When they are first hatched, the young scales are called crawlers and will move about at this time. At this time, they will crawl directly to the leaves and will spend most of the summer feedings on the leaves and excreting honeydew. During the winter, they will return to the stems and branches of the tree.
Tulip tree scale is a type of soft scale. Female tulip tree scales can be up to three-eighths inches long with orange ridges on a brown body. They can be found on tulip trees, magnolia, walnut and linden. They are often found to be at the crawler stage during September.
By now, you're probably wondering if your tree has tulip tree scale. Well, to be sure, go out and look around your tree. If you notice orange bumps or a sticky substance around your tree (including on the ground), you probably have tulip tree scale.
If you determine that you have it, the next step is to treat your tree. To determine what type of treatment best suits your individual situation, review a copy of Purdue Extension publication E-29-W, "Scale Insects on Shade Trees and Shrubs." You can obtain a copy by contacting your local Purdue Extension Office or by logging on to http://extension.entm.purdue.edu/publica....
As always, if you have any questions or would like information on any agriculture, horticulture, or natural resource topic, then please contact your local Purdue Extension Office at 448-9041 in Clay County or 812-829-5020 in Owen County, or reach me directly at firstname.lastname@example.org.
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* Aug. 22 -- Start of the Indiana Master Naturalist Course, Clay County Extension Office, 6-9 p.m. Cost $50. Contact 448-9041 to register.