Plant – Insect Interactions
Exam 3, May 5, 2006
1. 25 pts: For ANY TWO of the following types of natural enemies. Entomopathogens, Predators, Parasites, Competitors, describe each of the following:
a)How either plant or insect chemistry is used by the natural enemy to exploit the herbivore. Provide one example, giving the specifics of the interaction.
b)How there can be adverse effects of plant chemistry on the natural enemy? Provide one example, giving the specifics of the interaction.
c)Identify one person who has worked on this question, and identify what they discovered.
2. 15 pts. Describe some of the ways in which insects use micrroorganisms to improve their ability to exploit plants. Provide examples in each case. Identify one person who has conducted work on insect – plant - microbial interactions, and describe what they did.
3. 20 pts. Answer EITHER of the following:
a)What are some features of environment that select for tightly linked vs. more general pollinator relationships? What environmental features are commonly associated with insectivorous plants? What are some similarities between pollination and insectivory from the plant’s perspective?
b)Describe some rewards plants give pollinators besides nutrients. What are some of the conflicts of interests between plants and their pollinators? Identify one person who has worked on symbiosis from this perspective, and describe the framework they constructed.
4. 20 pts. Answer EITHER of the following:
a)What are some features of modern production agriculture that lend themselves to herbivore outbreaks? What are some ways in which an understanding of plant - insect interactions can be developed to alleviate them? What are some of the limitations / challenges of these improvements
b)Describe some of the challenges that limit our ability to understand the roles of insects in plant community structure and ecosystem processes. Provide one hypothesis whose testing you feel would make a significant stride toward improving this understanding, and describe how you would test it.
5. 20 pts. Describe (one paragraph) each ANY TWO of the following:
a)Gene for Gene Hypothesis: How it works, and its originator
b)May Berenbaum’s description of key steps in the coevolutionary process
c)Theodore Jermy’s challenge to plant insect – coevolution. Its basis and your evaluation.
d)Key elements of Dan Janzen’s definition of coevolution
e)Michael Singer’s description of how human activities have altered insect-host associations: His evidence and your analysis of his argument.
f)Anurag Agrawal’s evaluation of the “enemies release” hypothesis: His evidence and your analysis of his argument.
g)An interaction in which herbivory by a vertebrate affects subsequent herbivory by an insect. Describe the plant, vertebrate, and insect, underlying chemistry, and direction of the response
h)A group of plant compounds that are important in both defense against herbivores and attracting pollinators. Describe their functions in each case.