Sunday, August 14, 2011

Dry Site Sycamores

Except for a six week drought that went from mid-June through most of July, Blue Jay Barrens has had an exceptionally wet year. It’s interesting to watch moisture loving plants try to claim a place on a dry site in these situations. The Sycamores that try to grow in waterways coming off of the dry, rocky hills are a good example of this.

The waterways concentrate the rain runoff and provide a wet habitat that is prolonged by seepage water that flows from the gravel for several days after a rain. The Sycamores put on a lot of rapid growth during the rainy years and die back in the dry times. In an earlier time, these Sycamores managed to grow quite tall. The dead branches illustrate what happens when we get a couple of back-to-back drought years.

The trees may appear perfectly healthy from a distance, but a closer examination shows that all is not well with the tree. The abundant water that allows for rapid growth doesn’t free the tree from all stress. Growth deformities, disease and insect damage leave their marks.

One of the larger of the insects feeding on the Sycamore was this Bagworm. This species of moth larva constructs a silk bag that it decorates with bits of plant material. The result is a protective casing in which the larva spends its entire pre-adult life.

Head and legs are all that ever leave the bag. I seldom find the larvae actively feeding. At the slightest disturbance the larva will pull the bag over its head and wait for danger to pass. I was able to get several shots of this guy before my head bumped a dead branch and spooked the larva into hiding.


  1. The bag worm is actually a pretty creature. I remember my Dad working so hard to get rid of them.

  2. Thanks, Katie.

    Hi, Lois. At least the head is cute. When I was a kid living in a residential section of St. Louis, a bagworm infestation could stir up a mass of angry villagers faster than Frankenstein's monster.