Woolly Bear Caterpillars
Michael Singer at Wesleyan University discovered that, when healthy, tiger moth larvae, also known as woolly bear caterpillars, focus their diet on nutrient-rich food, but switch to eating plants with high levels of toxic substances when infected with parasites. The basis for this preference, Singer learned, has to do with taste. Parasitic infection by tachinid flies, for example, increased the firing rate of caterpillar taste cells in response to toxic pyrrolizidine alkyloides (PA), compared to uninfected caterpillars, enhancing their preference for PA-rich food. Eating such food, Singer found, improved infected caterpillar survival.
Chimpanzees
When experiencing stomach upset, chimpanzees turn to noxious plants, such as the bitter leaf plant, to help handle any intestinal parasites that might be causing their symptoms. “They remove the bark and leaves like a banana,” explains Michael Huffman of the University of Kyoto. “Once they suck out the juice, the chimps spit out ...
