Lecture 12

Question 1

What are the four trophic levels?

Answer 1

• First: single plant
• Second: herbivores
• Third: parasitoids
• Fourth: hyperparasitoids

Question 2

What is important about maintaining the stability of the food web?

Answer 2

links between species (the more the better)

Question 3

What is a trait mediated interaction unit (TMIU)

Answer 3

an initiator alters a trait in a shared resource (plant) that feeds back into an effect on a receiver

Question 4

Indirect trait mediated response across trophic levels

Answer 4

the induction by herbivory leads to altered volatile emission that is used by parasitoids to locate the herbivore

Question 5

What are some important aspects of trait mediated effects in insect communities?

Answer 5

• insect species induce specific responses in plants
• insect species vary in the scope of affecting plant phenotypes as sequential herbivore
• insect species vary in the temporal effect size on plant phenotypes
• insect species differ in their response level and direction to previous damage

Question 6

Are interactions between herbivores symmetric or asymmetric?

Answer 6

asymmetric
interactions may be specific for genotypes

Question 7

What drives specificity in interactions among species?

Answer 7

plant physiology

Question 8

How do feeding guild, feeding pattern and herbivore specific elicitors drive specificity in interactions among species?

Answer 8

feeding guild: sap sucking vs leaf chewing induce different hormone pathways in plants
feeding pattern amount and pattern of damage induces different responses
herbivore specific elicitors: each herbivore species has a different mix of elicitors in their saliva
e.g. groups feeding on the ground vs on the top of the plant still affect each other indirectly