Woolly beech aphids, udel.edu
Cynipid Wasp galls, uwex.edu
Two interesting samples came into the office this week. The first was a beech twig with white, fuzzy ‘stuff’ moving on it. The second was a round tan and maroon mottled one-inch round ball. Of course, the respective clients want to know the identity of both ‘things’. Both clients spend ample time outdoors observing nature. They recognized something new, something that didn’t normally appear there. We are here to provide them with the answers.
After placing the beech twig under the microscope, it was pretty easy to see individual insects, aphids, waving their curled-up butt ends in the air. Covering the aphid’s back, was white thread like pieces of waxy filaments. The insects are Woolly Beech Aphids, Phyllaphis fagi. This aphid feeds on a single host species, beech. Aphids have a piercing/sucking mouth part they inject into the leaf tissue to suck up the plant juices. These aphids are gregarious, tending to cling together on the undersides of the leaves. Even though they may be numerous in population, their damage does not cause much injury to the plant. The leaves will be falling within the next month and have done their job for the tree. Aphid feeding at this time of year will not stress the beech tree, therefore no control measures are needed. But aren’t they cool to watch?
woolly beech aphid, Hannah Nendick-Mason photo
Oak Gall
The next client’s object looked it should be fruit. Round and firm but fleshy with a spotted or marbled skin. I usually cut open fruits to examine their seeds to identify the family to which they belong. Apples have five seeds, stone fruits have single pits. After cutting through the center of this supposed fruit, I found no seed or pit but a hollow area containing more than ten tiny wiggling larvae. It was not a fruit. It was a gall; malformed plant tissue formed to encase and house the egg and subsequent larvae of a very small cynipid wasp. The larvae produce hormones that cause the leaf tissue to grow into the ball shape. The galls do not harm the tree but can be unsightly. Our gall was found on the ground, after it fell from the tree or leaf, probably an oak. Again, no control measures are needed as the galls are only cosmetic and not causing damage to the tree.
I am thankful to these observant nature watchers for sharing their oddities with me and the UConn Home and Garden Education Center.
-Carol Quish
October 23, 2012 at 8:09 pm
I read with interest your entry about the Woolly Aphid entry. Did you know that this little insect is the food plant on the Harvester Butterfly?
Most butterfly caterpillars eat plants of course, but this one is the exception. If you look up the Harvester Butterfly, you will find out all the details. I belong to both the Massachusetts Butterfly Club and the North American Butterfly Association, and we have talked about this different associaton for many years now. I just thought that you might be interested in this little sideline.