Some types of pine trees are attacked and fed on by pine bark beetles.As the beetles feed, they girdle the trees, destroying the phloem layer and killing the trees.Pine bark beetles are also associated with the blue stain fungus, which grows in their frass (feces).As they attack the trees, the beetles also inject the fungus.The fungal hyphae grow into the tree and follow its xylem cells, blocking the flow of xylem and causing rapid tree death.This information suggests that the relationship between the pine bark beetle and fungus is _______, while the relationship between the beetle and the pine tree is _______.
A) mutualism; parasitism
B) mutualism; commensalism
C) commensalism; parasitism
D) commensalism; herbivory
E) parasitism; parasitism

Question

Quizplus · Accepted Answer

The relationship between the pine bark beetle and fungus is commensalism because the beetle benefits from the fungus by using it as a substrate for laying eggs, while the fungus is neither helped nor harmed. The relationship between the beetle and pine tree is parasitism because the beetle feeds on the tree, causing harm and ultimately killing it.

Some Types of Pine Trees Are Attacked and Fed on by Pine