Dutiful Host

To the left is an example of a parasitoid (something I've often called my brother) dramatically changing the behavior of its host.

In this instance, a braconid wasp injected upwards of 80 of her eggs into the flesh of a geometrid moth caterpillar. The caterpillar then went about its normal routine as the eggs developed and incubated inside of it, munching on leaves and smoking its hooka pipe.
But come hatching time, the wasp larvae burst from the caterpillar all at once--but this didn't kill the caterpillar (even though the larvae had been feeding on the caterpillar's insides). Not in the least. Instead of screaming and dying a la Alien, the caterpillar is left alive, but lives with one final directive: to protect the young wasps who have emerged only to immediately pupate.

The caterpillar denies itself all food and sustenance, suppressing its own urges at self-preservation to stand guard over the little cocoons (as seen in the photo). If any predators come too close, the caterpillar fends them off. Field studies have shown that the wasp pupae thus guarded have a 50% increased survival rate over those that aren't guarded. Once the wasps emerge from their cocoons, the caterpillar dies, just as if Ernest Hemingway had written the entire drama himself.

Thanks for the article, Mary. Life is a little less enjoyable now.

Photo source: Science Daily