See-through-trees? What could it be?
Upon closer inspection of this building's foundation planting in Toledo, Ohio, the crabapple and beech trees were being fed upon by gypsy moth catepillars. It appears they began their feeding frenzy on the crabapple, and once those leaves were eaten, they quickly moved out and began feeding on the beech trees on either side. What you don't see in the photo are several spruce trees that are also a caterpillar favorite. The tree that was missing at this location and is the caterpillar's favorite, is the oak. But even without its favorite, there was plenty to feed upon. Gypsy moths are known to feed upon a wide variety of trees and shrubs that number in the hundreds.
The catepillars that were recently feeding ranged in size from just over an inch to 2.5" with a little room to grow as some will reach 3" in length. There was no indication that pupation had begun. The gypsy moth caterpillars are hairy and have distinctive pairs of blue and then red dots down the length of its body. As they reach the 2" length they are feeding machines and become obvious to even the novice of gardeners. It is amazing to me that you can hear their activity: primarily their frass falling onto other leaves that still remain. It sounds as though it is a gentle rain - imagine that it is "raining frass."
Soon the moths will be out and the male in search of mate. The male moth is brown in color and flies during the day. The female is a little larger and white in color. The female moth does not fly, but instead gives off a phermone trail that can attract the male to her. The eggs being laid later this year with be next year's caterpillars, as there is only one generation per year.
Information about the gypsy moth in Ohio can be found on the Ohio Department of Agriculture's website at: http://www.agri.ohio.gov/divs/plant/gypsy/gypsy-index.aspx It is also important to note that there is a gypsy moth quarantine in Ohio.