Nematodes which live inside horned passalus beetles which can benefits both of them. Although Nematodes are parasitic and they feed of on the beetles’ hemolymph, which is basically the insects’ blood, and will eventually suck up all of the beetles available energy and kill them. Whether this relationship is harmful or mutualistic is still a question?
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Research had previously shown that about 70 to 90 percent of Odontotaenius disjunctus, or as commonly known as horned passalus beetles are “home” to thousands of nematodes, thich are parasite that live inside the beetle’s abdomen. These nematodes can drain the beetle’s energy by sucking its hemolymph, and the beetle can become weak due to lack of energy, which can help them consume more wood, according to Andy Davis, an ecologist at the University of Georgia in Athens. He also predicted that beetles that eat more are more likely to be infected since they eat more food. He and his undergraduate student Cody Prouty had set up a lab, where he captured 113 beetles that they found near the campus and put each individual inside a container with a chunk of wood. After three months, they took out the beetles from each container and weighed the amount of wood left in the each container. They then dissected the beetles in search for nematodes. Beetles with nematodes had found to digest 0.77g of woods everyday. This result had found to be more than 15 percent of the uninfected beetles, which are found to be 0.67g per day. In order to answer the question, Andy and his team need to figure out the difference in beetle’s eating habits before and after they are infected by larvae. But more importantly, they need to figure out how the larvae gets into the beetle’s abdomen.
This research is part of a bigger idea of whether parasites are extremely crucial in the ecosystem, and there are many ways in which the parasites can interfere with the ecosystem. It had shown that this relationship is mutualistic instead of parasitic since the larvae benefits the beetle.. Now scientists are questioning whether adult Nematodes that live in rotting logs are pre-digesting the wood, said Sheena Cotter from the University of Lincoln in England. It seems as if these nematodes are just being being harboring by the beetles in corporating to digest woods for their own benefit.