Nebraskaland

October 2024 Nebraskaland

NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.

Issue link: http://mag.outdoornebraska.gov/i/1526936

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50 Nebraskaland • October 2024 THE LAST STOP Nature isn't always for the faint of heart, but it is consistently fascinating. For example, take the gruesome scene I found playing out on the siding of my garage last fall. A green caterpillar was thrashing about while numerous larvae were crawling out of its body. The scene was being observed by several small wasps. Fortunately, with the help of friends — especially Dr. Enakshi Ghosh of Colorado State University — I can explain the scene to you. The caterpillar was a larva of a cabbage white butterfl y, an invasive species from Europe. The emerging larvae were the off spring of a European parasitoid wasp introduced to North America to help suppress populations of the butterfl y. Adults of that wasp species fi nd caterpillars by following the scent plants release as a response to the caterpillar's feeding activity. When a wasp fi nds a caterpillar, she inserts her ovipositor (a skinny tube eggs feed through) into it and lays up to 30 eggs inside the hapless creature. Just to punch up the story a little, the wasp also introduces a virus into the caterpillar that takes over its brain and keeps it alive and moving, even as its innards are consumed by the wasp's kids. That turns the caterpillar into a kind of guardian for the larvae inside it by repelling "hyperparasitoids," which are wasps that try to lay eggs on the larvae of parasitoid wasps. I know, right? Anyway, what I was seeing was wasp larvae exiting the caterpillar and immediately spinning yellow fuzzy cocoons, inside which they'd pupate and become adults. The larvae were probably the babies of the initial parasitoid wasp, but they might also have been the young of a second wasp that laid eggs on the larvae of the fi rst. It's all very complicated. Oh, and those small wasps hanging around while all this happened were yet another species of hyperparasitoids. They were waiting to lay eggs on the wasp cocoons as soon as they were created. As a result, when I checked back a few weeks later and found empty cocoons, I didn't know what species had emerged from them. It might have been a wasp that laid eggs on the caterpillar, a wasp that laid eggs on those eggs, or a wasp that laid eggs in the cocoons of either of those others. Happy Halloween. This looks like a lot. There's even more happening than you might guess. CHRIS HELZER By Chris Helzer GARAGE CARNAGE

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