Look closely. Look VERY closely.
See those "ornaments" hanging on this formerly beautiful Japanese maple?
Those ornaments or bags are 1 1/2" to 2" in length. The bags are the living quarters of a female bagworm and eggs. The bags can very well destroy this beautiful young tree and any of the juniper or evergreen bushes around it.
A bagworm, or Thyridopterex ephemeraeformis, is a white moth that lays eggs on any plant with leaves to chew. However, it prefers to lay its eggs on the needled evergreens: juniper, arborvitae, cedars, cypress, pine, hemlock or spruce. Each bag contains one female moth who dies in the bag as soon as she lays around 500+ eggs in each bag. The eggs overwinter and hatch in May.
Control bagworms with a one-time spray of BT (Ibacilllus thuringiensis; Dipel, Thuricide, etc.). Spraying starts in northern Arkansas the end of May/early June, and in southern Arkansas early June. The worm larvae are 1/8"-1/4" in length.
By the time the bags have formed, only hand picking the bags off the tree will work; the spray will not permeate the bags. Obviously hand-picking will not work for a larger tree; spray the larvae.
If the tree is totally browned out--all the green is consumed--the plant is doomed. It will never be a beautiful, robust plant again. The plant would need to be removed.
The Japanese maple featured in these pictures dropped every leaf. It managed to recover and grew new leaves with all the egg-filled bags yet hanging from it.
For more about other tree issues this time of year, play the September Master Gardener Mondays ZOOM recording and hear Berni Kurz discuss bacterial, fungal, and worm diseases of Arkansas trees in "What's Happening in the Garden?". Logon to Buddy Messages for the link, enjoy the talk and help our trees in the process!
Tree August 30, 2019
Tree September 30, 2019