Lecture 15

Question 1

describe the feeding method of specialized interactions insects & plants have

Answer 1

feed on plant & use it as protection

Question 2

galls

Answer 2

lay eggs in tissue of plants & manipulates tissue of plant to grow nutritive & protective tissue around the eggs

Question 3

describe the evolutionary history of insect-plant interactions

Answer 3

Insects were present at or before the origin of vascular plants

Question 4

The two most significant radiations in insect diversity coincide with the evolution of:

Answer 4

seed plants

flowering plants

Question 5

what did the evolution of flowering plants result in?

Answer 5

largest radiation of insect diversity

Question 6

when were most of the insect orders created?

Answer 6

during the evolution of see plants

Question 7

coevolution leads to the evolution of _____ _____

Answer 7

novel traits

Question 8

Describe the cycle of coevolution

Answer 8

1. Plant evolves new chemical defense: temporarily free from herbivory
2. Radiation of new, but related plant species
3. Insect evolves ability to overcome plant defenses: is temporarily free from competition
4. Radiation of new but related insect species
5. Cycle continues over evolutionary time

Question 9

the assoc b/w Brassica plants & Pierid butterflies was a result of?

Answer 9

coevolution

Question 10

describe the coevolution Brassica plants & Pierid butterflies

Answer 10

1. A Brassica species evolved defenses to avoid insect attack (glucosinolates)
2. Radiation of plants
3. A Pierid butterfly species evolved counter defenses to plants containing glucosinolates
4. Radiation of new Pierid species that could feed on plants containing glucosinolates

Question 11

what are the 2 main categories of plant defenses?

Answer 11

constitutive defenses

induced defenses

Question 12

constitutive defenses

Answer 12

always present & expressed

E is continually put into the defenses of this plant whether they are under attack or not

Question 13

induced defenses

Answer 13

only synthesized/produced in response to herbivory (injury)

Invest E only when attacked

Question 14

what are the categories used to categorize plant defenses?

Answer 14

constitutive defenses

induced defenses

mechanical defenses

chemical defenses

Question 15

what are mechanical defenses used in plants?

Answer 15

Waxy epidermal cuticles

Leaf toughness

Seed coats

Spines, prickles, thorns

Bark

Trichomes - hairs, scales & grandular (exude substances)

pitching out

Question 16

pitching out

Answer 16

trunk of the tree is a highly-pressurized tube, when a hole is made there is pinch & resin to close it

Question 17

when it is an effective defense for plants to use pitching out?

Answer 17

when insects lay eggs &/or feed

Question 18

what type of plants use glandular defense?

Answer 18

carnivorous plants

Question 19

primary metabolites include:

Answer 19

AAs, sugars, nucleotides & lipids

Question 20

primary metabolites function in _____ & _____

Answer 20

growth & reproduction

Question 21

what is an ex of primary metabolites used in chemical defenses?

Answer 21

high sugar content – make the fruit less susceptible to herbivory, many insects prefer to feed on other parts of the plant (increases fitness b/c they need seeds)

Question 22

what are the 2 grps of chemical defenses in plants?

Answer 22

primary metabolites

secondary metabolites

Question 23

primary metabolites are found ________

whereas,

secondary metabolites are found ______

Answer 23

throughout the plant kingdom

in related grps of species (shared common ancestry)

Question 24

secondary metabolites

Answer 24

Often co-opted metabolism by-products

Question 25

what are the modes of action in secondary metabolite defenses?

Answer 25

Feeding & oviposition deterrents Toxicants Antimicrobial activity Attractants (smell, colour, taste) for pollinators & parasitoids

Question 26

what are exs of defensive chemicals produced by plants?

Answer 26

Gluccosinolates are only present in Brassicaceae Nicotine in tobacco Tannins in tea & many other pants Salicylic acid (Aspirin) in willow bark Caffeine, morphine, cocaine, cannabinoids, myrcene

Question 27

what is the role of limonene in interspecific communication?

Answer 27

distasteful to herbivores causing them to stop feeding

Question 28

what is the role of menthol in interspecific communication?

Answer 28

warns herbivores that the plant is toxic to them before feeding commences

Question 29

is limonene volatile?

Answer 29

no, non-volatile

Question 30

is menthol volatile?

Answer 30

yes

Question 31

phytoecdysones

Answer 31

secondary metabolites plant steroids similar to insect molting hormones can interfere with molting when ingested

Question 32

semiochemicals

Answer 32

chemical communication volatile

Question 33

allelochemicals

Answer 33

facilitate interspecies communication

Question 34

allomones

Answer 34

Produce negative response in insects Repellents, deterrents & toxins

Question 35

kairomone

Answer 35

Benefits the recipient Harms the emitter

Question 36

describe the chemical defense of caterpillars

Answer 36

produces volatile secondary metabolites that are detected by other insects how they function depends on the indiv that detects it

Question 37

indirect defense (idk if OT)

Answer 37

plant makes use of a third party to defend itself, using secondary plant metabolites to call for assistance

Question 38

what are the morphological adaptations seen in insects? (2)

Answer 38

Ex: acorn weevil – larvae feed on seeds of acorns, have specialized mouthparts that can grind through the acron to deposit eggs Ex: horntails –feed on bark of tree, deposit eggs to pierce through bark to deposit eggs where they can feed

Question 39

what are the behavioural adaptations seen in insects?

Answer 39

Eat parts of leaves to avoid or limit production of defensive compounds Chew a ring of tissue, cuts off the ability of plants to transport metabolites for defense

Question 40

what is an ex of a behavioural adaptation seen in caterpillars?

Answer 40

trenching – seen in leaves with caterpillars

Question 41

behavioural adaptations used by plants lead to the production of what?

Answer 41

secondary metabolites

Question 42

what are exs of biological conditioning seen in insects?

Answer 42

Ex: inoculation of plant with fungi (& bacteria or both) to alter/suppress plant defenses or improve plant nutrition for offspring Mycangium – structure on body adapted to transport spores of symbiotic fungi

Question 43

exs of detoxification enzymes

Answer 43

the parsnip webworm can metabolize furanocoumarins & neutralize plant defenses saliva - Injected into plant tissues to reduce production of or break down induced secondary compounds (ex: corn earworm caterpillars feeding on tobacco plants)

Question 44

sequestration

Answer 44

Storage of toxic/distasteful secondary plant metabolites in tissues (of insects) become distasteful & poisonous to predators

Question 45

what insects sequester cardenolides? (3)

Answer 45

turnip sawfly milkweed bug monarch butterfly

Question 46

what adaptation to overcome plant defenses is accompanied with aposematic colouration?

Answer 46

sequestration

Question 47

substitution of an NA has enabled insects to do once? How many times did this happen?

Answer 47

genetic resistance enabling insects to feed on plants containing cardenolide poisons occurred 4 diff times leadingto4 diff orders

Question 48

what is an adaptation to overcome plant defenses that occurs at a pop level response?

Answer 48

mass attack

Question 49

describe the mass attack of bark beetles & mountain pine beetles

Answer 49

females need to bore through bark to deposit eggs, when this occurs, the holes they bore fills up with sticky material, the beetles can get stuck in it & die When the female finds a suitable tree she produces an aggregation pheromone to induce beetles to go into the tree, many beetles start going into the tree Limited amount of pitch the tree can produce (sticky material) Have a high enough number of beetles to go into the tree & lay eggs The number of beetles are higher than the amount of pitch the tree can produce to kill them all Once in the tree, produce antiaggregation pheromone to indicate that the tree if full