“As far as relationships go, parasitism may seem particularly selfish: one partner benefits at the expense of another. Many parasites even alter the behavior of their hosts to get what they need. Parasitoids are similar, but they usually spend a significant portion of their lives living inside or on their hosts’ bodies and controlling them from the inside-out, before ultimately killing and often consuming them.”
So begins an article in Science Daily featuring research by Melissa Bernardo, a PhD student in biology working with Michael Singer, associate professor of biology, associate professor of environmental studies. Bernardo has been studying how parasites and parasitoids influence feeding behavior of their hosts. Many scientists believe diet manipulation “could be reasonable because the parasite might need different types of nutrients than the host,” according to the article. But this phenomenon has been studied little in the past, and hasn’t been shown conclusively.
In a series of experiments, Bernardo found that when wooly bear caterpillars were allowed to choose between a protein- or carbohydrate-rich diet, those who were unparasitized chose a protein diet, while those parasitized by a type of wasp preferred a carbohydrate diet. In effect, Bernardo said, “The wasps are making their hosts carb-load.”
The article continues