19

Question 1

Many ways to eat a plant? 4•

Answer 1

•Insect herbivores
•Parasitic Herbivores
•Mammalian herbivores
•Some omnivore

Question 2

Mammalian herbivores tend to be?

Answer 2

Generalists (polyphagous)

Question 3

Insect herbivores are mostly?

Answer 3

Highly specialized (monophagous)

Question 4

About what percent of insects feed on only at most 3 plants?

Answer 4

> 90%

Question 5

Important ecological and evolutionary causes of host specialization?

Answer 5

Interactions drive traits of both to specialization and sometimes coevolution.

Question 6

!!What can host specialization eventually lead to? 3•

Answer 6

•Plant defense
•Herbivore counterdefense

Question 7

Resistance traits?

Answer 7

A trait in a plant that reduces the preference or performance of herbivores.

Question 8

Deterrence?

Answer 8

A trait which inhibits feeding or oviposition when present in a place where herbivores would, in its absence, feed or oviposit.

Question 9

Physical deterrents?

Answer 9

Any sort of deterrence that occurs morphologically, such as thorns.

Question 10

!!Chemical deterrents?

Answer 10

Any sort of chemical deterrences in the surface of the leaf, such as phenolics and oxidative enzymes that create a sticky surface for aphids.

Question 11

Trichome terpenes deterrent?

Answer 11

Aphids reared on accessions with terpenes in trichomes have reduced longevity and fecundity.

Question 12

Terpenes are?

Answer 12

Carbon based compounds that create a bitter taste and have anti-fungal properties.

Question 13

Chemotypes with terpenes reduce what?

Answer 13

Aphid landing preference.

Question 14

Why don’t all plants have trichomes?

Answer 14

•Energetic costs
•Water lost
•Ecological costs: repel benefits

Question 15

Two big types of trichomes?

Answer 15

Sticky and velvety.

Question 16

How many genes decide what trichomes does the plants make?

Answer 16

One gene

Question 17

The sticky trichomes have what chemical?

Answer 17

Acylsugar

Question 18

Acylsugars?

Answer 18

They are sticky and smelly sugars that are very lipophilic (may desiccate herbivore membranes).

Question 19

Toxins interfere what type of metabolism?

Answer 19

Primary

Question 20

!How does nicotine enter the nervous system of caterpillars?

Answer 20

Their saliva is basic in base: R-N = lipophilic.

Because of their lipophilic properties, they will not bind with the mouth membranes. They thus pass thought to hemolymphs, which is acidic in acid: R-NH = water soluble. They then move to the ganglia and into the blood stream.

Question 21

Counterdefense from caterpillars?

Answer 21

Halitosis. They are able to detoxify nicotine and let it all out. But some of that nicotine is taken into the hemolymph and then since the hemolymph is moving all through the body, it interacts with the spiracles of the body. Some of that nicotine is excreted out of the body of the caterpillar. If a predatory spider comes that is not able to handle the nicotine, the caterpillar can defend itself using the plant’s defenses.