Insect Invasion of Mutiple Tree Types

Asked September 13, 2018, 11:06 AM EDT

I live in Davidsonville, Md. on a two-acre plot, half in trees. Predominant natives are yellow poplars, sycamores, sweet gum, silver maples, pine, dogwood, and black cherry. Others added by previous owners include a sugar maple, a weeping cherry, Japanese maples, and a teacup magnolia. Insects smaller in size than a pin head, light-toned, almost translucent and similar in appearance to head lice are on every leaf of the sugar maple and adjacent Japanese maple and weeping cherry. The sugar maple is fully mature, at least 40 years old. Several limbs have died this year. The insects appear to have come from webbed tent structures in the tree. (They definitely are not tent caterpillars.) I cut out all the tents I could reach. A neighbor with same problem on a river birch calls the insects Mimosa insects. Never heard of them myself, but whatever they are they are devastating my trees. I am unable to send photos. Can you offer identification and recommendation for what I can do?

Anne Arundel County Maryland fall webworm trees

1 Response

The tents in the trees sound like fall webworms. We are receiving a lot of questions about this insect. See our website http://extension.umd.edu/hgic/fall-webworm-trees

There are predators and parasitoids that attack and kill fall webworm. You can open the webbing with a pole pruner and expose the contents to birds. Also, the birds will take the webworms out themselves. You do not have to do anything. The webworms rarely consume enough leaves to affect growth. Larvae are or will be getting ready to pupate and no chemical control is recommended. Your trees should be fine next season.

We cannot say for sure what the clear insect that you are noticing on your trees foliage. This is nothing to worry about. It is late in the season and the trees have stored enough carbohydrates in their root system to put out new growth next season. If you have dead limbs in the sugar maple, you can contact a certified arborist for an onsite diagnosis regarding the health of the tree and to prune dead wood. http://www.treesaregood.org/

mh