The Gall!

 gall collection Nature is the ultimate adventure story.  Filled with sex, death, devotion, pestilence,  battle, enslavement and disaster, it makes  Stendahl look like a comic book.  In comparison to natural history, War and Peace is uneventful.  Let’s face it, if  what you saw on a PBS “Nature” episode was translated into a human plotline, you’d never watch it and say, “Now, THAT was realistic!” 

Nature’s true-to-life stories are more complex and dramatic than any fiction.   Consider life on a wildflower stalk.  By Fall, goldenrod is a hold-out among blooming plants.  Nectar-loving bugs seek it out with gusto.  A single spray can be a frenzy of insects.  Pollinators come, but predators do too.  With bad timing, that nectar-rich repast could be a final meal.  If a boy and girl of a given species should visit simultaneously, love can bloom among the blooms, as it were.   Boy meets girl on botanical campus, and the rest is history.  Sex and death in a centimeter.

But the stems of certain goldenrods look as though they’ve swallowed a ping pong ball, others as though they’ve eaten a tiny football.  Still more have their proximal leaves contorted into a bunch.   What’s going on? 

ball gallThe plant has been invaded, becoming a  sort of unwilling insect incubator.  The protuberences,  known as galls, are the result and can be found in any stand of goldenrod.  Each shape is the signature of the insect that made the plant into its unwitting nursemaid.

The most common goldenrod gall is the “ball” gall.  In Spring, the Goldenrod Gall Fly lays an egg on the growing plant.  When hatched, the larva burrows into the stem of the plant, eating  out a chamber within.  This stimulates the growth of the gall around it, thus providing more food for the developing larva.  By winter the larva is fat and juicy-perfect for ice fishermen to use as bait!  Many the sliced thumb is the result of cutting through a woody gall to get the worm out. 

elliptical gallThe “elliptical” gall is made by the Goldenrod Gall Moth.  A variation on a theme,  the moth egg is laid onto a leaf in Autumn and overwinters there.  In Spring, the egg hatches and burrows  as a caterpillar into a goldenrod bud. The elliptical gall forms and the caterpillar feasts all summer from inside.  The lifecycle is completed in the Fall and a small empy chamber is left  for possible use over winter by a tiny spider or insect.

bunch gallThe “bunch” gall is the handiwork of the Goldenrod Gall Midge who oviposits at the tip of the plant’s main stalk.  The stem fails to elongate, and the leaves back up on each other like cars in a rear-end collision,winding up  twisted together.  This suits the midge egg  and other insects who take advantage of the thick swirl of leaves.  The cluster forms a home for many, including the lovely Crab Spider, who slowly changes color to match the plant it occupies.  The gall midge has its own curious feature:  throughout its reproductive life it produces either male offspring or female, but never both at the same time.

Never mind fiction, you can’t make this stuff up.

See you on the trails,
Diane Tucker, Estate Naturalist

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One Response to “The Gall!”

  1. Bridget Willard Says:

    WOW!

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