Leaf Miner: An Artist’s Journey

Posted by on Sep 5, 2014 in insects, leaves, summer, Unmowed Blog, wildlife | 1 comment

The Highlights Foundation in Boyds Mills, PA. An oasis of calm and creativity, a place for writers and illustrators to work. In between revising chapters and tinkering with adjectives, I took a walk along one of the woodland trails, and discovered that an artist had been this way before me.

Not an illustrator of children’s books; an illustrator of leaves.

It looks as though some demented graffiti artist has been spray-painting leaves in crazy, random patterns. But this botanical doodling is the work of an insect called a leaf miner.

leaf miner on white snakeroot There are hundreds of species of leaf miners, which are the larval form of various kinds of beetles, moths, or flies. Like human artists, they come in many shapes and sizes. Each species creates a certain kind of artwork on–or rather in–the leaf. Some make a big circle, others make only a short path, others make these crazy winding scribbles.

The little bugs start off life as an egg, which their mother thoughtfully lays in the giant sugar factory known as a leaf. When the egg hatches out, the tiny larva—small enough to fit between the top and bottom of a leaf–starts chewing on the leaf’s soft tissues. Once it has eaten everything it can reach, it has to move on. The larva doesn’t have much in the way of legs—just short little stumps. No problem—the little bug just braces itself against the sides of the leaf, and pushes forward. Take a bite—and push.

Slowly, inexorably, the leaf miner eats its way through the center of the leaf, like a miner tunneling through the earth. Wherever it goes, it leaves a trail. The larva has no eyes (there’s not much to see inside a leaf, I suppose) so it doesn’t look to see which way it’s going. If it gets to the edge of the leaf, it just turns and starts chewing another way.

A leaf is the perfect hide-away, not unlike the writers’ cabins you stay in at Highlights—waterproof roof, shelter from the hungry beaks of predators, and everywhere you go there’s lots of great food.

As its life wears on, the leaf miner eats and eats, growing with every bite. The widening trail shows the growth of the insect. And after a long adolescence of zigzagging and criss-crossing and looping the loop, it finally reaches the end of the road.leaf miner emerging spot The leaf miner pupates, and metamorphoses into an insect with wings. It chews its way free, and flies away, leaving the trailside artwork behind to delight passersby.leaf miner tunnel



One Comment

  1. Your leaf miner piece is truly fascinating! I had no idea
    before I read it how the critters work, or even that there
    is more than one leaf miner.

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