Tuesday, August 24, 2010

Little Oak with Big Caterpillar

As I emerged from the woods, I stopped to scan the little barrens opening I was about to enter. To my right I could hear something chewing and I turned to find this caterpillar a few feet away busily devouring a leaf of a small Chinquapin Oak, Quercus muehlenbergii. I believe this is the larva of a White-Dotted Prominent moth, Nadata gibbosa. The caterpillar is also commonly referred to as the Green Oak Caterpillar for what should be obvious reasons.

There were several leaves on the tree showing signs of feeding activity and a couple leaves that had been eaten right down to the petiole. From its size, I imagine this larva will soon be pupating, so the tree shouldn’t be losing too many more leaves.

Since it already had my attention, I decided to check the tree over to see how it was doing. There was a lot of damage due to egg laying by the 2008 brood of periodical cicadas. There is a good likelihood that many of these branches will break as the tree ages.

Something used silk to hold these leaves together and then ate the lower surface of the attached leaf from the safety of a leaf sandwich. There were several of these areas on the tree, but I didn’t find any sign of the culprit.

This small oak had an enlarged base typical of most small trees on the barrens. The top growth on these trees often dies back and a new shoot emerges from the base. Since the base has been continually growing from the time the seed sprouted, it becomes disproportionately larger each time the old top growth dies and a new one begins.

It’s not an easy life for these little trees. The barrens don’t offer the best of growing conditions, at least for larger plants that need an adequate water supply. It takes a lot of luck for the small oaks to reach a point where their survival would be considered secure.

2 comments:

  1. Hi Steve...thats quite the muncher and if your can hear him eating then your to close.. or I should say that would apply to me anyway!! : }
    Tent caterpillars are a pest here right now and they can do a number on a tree in no time to!
    Had rain but not even enough to wet the ground for some poor withering plants!!

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  2. Hi, grammie g. That caterpillar was so loud, I wouldn't have been surprised to turn and find someone eating an apple beside me.
    Our tent caterpillars have finished for the year, but you can still find some old dirty tents hanging in the trees.
    Our rain stopped in mid July and we haven't had but a sprinkle since.

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