The Plant That Wasn't for Eating

The shed smelled like dust and dried leaves and something faintly bitter that Maya couldn't name.

Her uncle Theo was supposed to be running the park now, which mostly meant he moved boxes from one shelf to another and complained about the last ranger's filing. He handed her a plastic tray with a torn label.

"Bug lady left this in June," he said. "If it's dead, toss it. If it's alive, I don't want to know."

The tray held rows of little brown cases the size of jellybeans. Cocoons. Some were plain. Some had bits of plant woven through the silk, tiny shredded leaves pressed into the walls like insulation.

Maya turned the tray toward the window light.

The cocoons with plant bits in them looked whole. The plain ones had holes. Small, round, neat holes, one per case, chewed from the inside out.

"These ones are broken," she said.

Theo didn't look up. "Then toss those."

She didn't. She lined them up instead. Plain cocoon, hole. Plain cocoon, hole. Plant cocoon, no hole. Plant cocoon, no hole. She went through all twenty-six. The pattern didn't break.

Something came out of the holes. That was the only thing that made a neat round hole like that. And whatever came out of the plain ones had not come out of the leafy ones.

She picked up a leafy cocoon and smelled it. That was the bitter smell in the whole shed.

There was a folder wedged under the tray. Field notes, printed, coffee-ringed. Maya read standing up. The entomologist had been raising tiger moths, the fuzzy kind, the caterpillars everybody calls woolly bears. The notes listed what the caterpillars ate. Then a separate list, underlined twice, of what they gathered.

Gathered, not ate. One plant name repeated down the column. The caterpillar chewed pieces of it and never swallowed. It carried the pieces into the silk.

"Theo," Maya said. "What eats a caterpillar from the inside?"

He finally looked over. "Wasps. The little ones. They lay an egg in the caterpillar, the grub grows inside it, and then it chews its way out. Nasty. Why?"

"Because half of these have wasps that made it out and half don't."

He came and looked. He was quiet for a second. "Huh," he said. "So the leafy ones fought them off."

Maya kept reading. The plant on the list wasn't food. The moths, when they hatched, wouldn't touch it. Adult tiger moths in the notes drank nothing much at all. The plant did one thing, and the notes said it in dry little words: the leaf carried a compound toxic to developing parasitoid larvae.

Poison. But only for the grub. The caterpillar built the poison into the walls of its own room before it fell asleep.

Maya set the leafy cocoon down very carefully.

"That's backwards," she said.

"What is?"

"The wasp lays the egg while the caterpillar's still crawling around eating. Right? Then later the caterpillar spins up."

"Sure."

"So when the caterpillar goes and finds this plant and stuffs it in the walls, it doesn't know if there's a wasp inside it yet. It can't feel the egg. It just does it. Every time. Before."

Theo shrugged. "Maybe it knows it's sick."

"No." She shook her head, because that wasn't it, she could feel that wasn't it. "The clean ones did it too. The ones with no wasp in them. They still went and got the plant. They still built the poison in." She pointed at the tray. "Look. The leafy ones with no holes. Those caterpillars were fine. There was never a grub. They poisoned an enemy that wasn't even there."

The shed was quiet again. Outside a bird did something in the gutter.

Maya was working it through, and it kept getting bigger instead of smaller.

The caterpillar couldn't have learned this. It only made one cocoon in its whole life. It didn't get a second try. It never saw its own eggs hatch, never met its parents, never watched another caterpillar get eaten and thought, I should avoid that. It just crawled out one day, found the one specific bitter plant it would never use for anything else, and packed its walls with a defense against a wasp it might not even have.

Something had to have taught it. But nothing alive had taught it. The teaching happened before it was born. It happened over more caterpillars than she could count, the ones that gathered the plant living a little more often than the ones that didn't, for so long that the gathering ended up written inside them, deeper than memory, in the place instructions come from before an animal has any thoughts at all.

"It remembers," Maya said slowly, "something that happened before it existed."

Theo laughed, not unkindly. "That's a bit much for a shed on a Tuesday."

But Maya wasn't being poetic. She meant it plainly. The caterpillar carried a fear it had never felt, of an animal it had never seen, and it acted on that fear correctly, once, in the dark, and then died as a moth that had no mouth for the very plant that saved its life.

She thought about all the caterpillars that had done it wrong. The ones who skipped the plant, or grabbed the wrong leaf. They didn't get holes chewed in them and then learn better. They just didn't make it, and the ones who happened to be right made the next batch, and the rightness piled up over such a long time that it stopped looking like luck and started looking like knowing.

Except nothing knew it. That was the part that kept opening.

"Theo," she said. "How would the first one know? The very first caterpillar that ever picked the right plant. It didn't have anyone to copy."

He opened his mouth and then didn't say anything, which was the most honest thing he'd done all day.

Maya put the leafy cocoons back in the tray. All of them. She was not going to toss a single one.

She held one up to the window. Inside the bitter walls something was folded and waiting, carrying an answer to a question no one had asked it, ready to fly out in spring with no idea it had ever won anything.

The cocoon was warm from her hand. She swore she felt it shift.