Final Exam

Question 1

Idiobont

Answer 1

those parasitoid species that permanently paralyse their hosts during parasitism, causing the cessation of host growth and development

Question 2

Kionobiont

Answer 2

parasitizes earlier host stages, host activity continues following the attack, and the association of the host and parasite is prolonged.

Question 3

Phenology

Answer 3

Phenology is the study of periodic events in biological life cycles and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors.

Question 4

ecological/economic injury level

Answer 4

The smallest number of insects (amount of injury) that will cause yield losses equal to the insect management costs. Economic threshold. The pest density at which management action should be taken to prevent an increasing pest population from reaching the economic injury level.

Question 5

epizootic

Answer 5

a disease event in an animal population akin to an epidemic in humans

Question 6

antibiosis

Answer 6

adverse affects on pest life history, those that reduce herbivores’ performance.
an antagonistic association between two organisms (especially microorganisms), in which one is adversely affected.

Question 7

antixenosis

Answer 7

adverse effects on pest behavior, avoidance traits, and those that affect herbivores’ behavior.
plant traits affecting herbivore behavior in ways that reduce the preference for, or acceptance of, a plant as a host by a herbivore.

Question 8

quantitative defenses

Answer 8

• post-feeding affects on the herbivore
• effects dependence on consumption, deter herbivores, or slow the growth of herbivores rather than the toxicity.
• may comprise a significant proportion of the dry weight of living plant tissue

Question 9

Qualitative defenses

Answer 9

• pre-feeding affects the herbivore, detering them from feeding on the host plant
• toxic in small doses
• often relatively cheap metabolically, a defense against unadapted herbivores
• present In low concentrations
• many plants employ both types of defense

Question 10

Rapid induced resistance

Answer 10

• rapid, begins to act immediately after an attack, targeting the herbivore
• may be localized or systematic
• can be elicited by low levels of herbivory

Question 11

Delayed induced resistance

Answer 11

• effect generations of insects subsequent to the one response for eliciting a response
• may have delayed-density effects, thus theoretically, can destabilize population dynamics and create cycles.
• generally need severe defoliation for elicitation
• driven by defoliation due to an imbalance of nitrogen and carbon

Question 12

Escape-and-radiate coevolution

Answer 12

• a hypothesis proposed that the coevolution and evolutionary arms race between insects and plants resulted in the vast radiation and diversity of species.
• an evolutionary innovation by either partner in a coevolutionary interaction enables an adaptive radiation, or speciation due to the availability of ecological opportunity.

Question 13

chemical defenses

Answer 13

A staggering array of plant secondary chemical defenses arise from photosynthesis and a few precursor pathways.
- Major classes of secondary compounds
~ terpenoids
~ N-containing
~ phenolics

Question 14

to grow or defend dilemma

Answer 14

They must grow fast enough to compete, and yet maintain the physiological adaptations (de- fenses) necessary for survival in the presence of herbivores and pathogens

Question 15

Enemy free space

Answer 15

• Some plant tissues may be inaccessible for some herbivore species because it may be too dangerous for them to feed on it.
• Jefferies and Lawton developed it in 1984
• herbivores may feed on suboptimal locations because they need to balance the quality of their food with the danger from natural predators

Question 16

top-down or bottom-up?

Answer 16

an old debate in forest entomology on whether insect populations are regulated from the top-down or bottom-up. The answer is both, it depends on the species, the functional feeding guild, the population phase, and the geography

Question 17

management for forest pests

Answer 17

• In most forests, insects do not require management. proactive strategies can reduce problems in the future
• Options
  ~ do nothing
  ~ pesticides
  ~ silviculture
  ~ biocontrol
  ~ semiochemicals

Question 18

BTK biological insecticide

Answer 18

• The most used biological-derived control is the bacterium bacillus Thuringiunsis used as a spray or expressed transgenically in field crops
• has to be injected by the insect. crystallized spores dissolve in the insect’s midgut and release an endotoxin that perforates the cells of the midgut, killing the insect.
• fast-acting and low vertebrate toxicity
  only effective during a short period in the insects development

Question 19

nucleopolyhedrohedrosis virus NPV

Answer 19

a viral disease of caterpillars that occurs naturally in Australia. As a pesticide, NPV is highly specific, safe and environmentally friendly (does not harm humans, wildlife or other insects), making it ideally suited to include in an integrated pest management approach.

Question 20

viruss/biocontrol-1

Answer 20

for tussock moths

Question 21

Gypchek

Answer 21

for spongy moths

Question 22

IPM - integrated pest management

Answer 22

• Includes ecosystem-based strategies focused on long-term reduction of pest damage through a combination of techniques
• can include biocontrol, habitat manipulation, change in cultural practice, plant resistance,

Question 23

Sivilculture

Answer 23

the art and science of controlling the establishment, growth, composition, health, and quality of forests and woodlands to meet the diverse needs and values of landowners and society

Question 24

semiochemicals

Answer 24

chemical substances produced by organisms such as plants and animals, such substances elicit a physiological or behavioral response in individuals of the same or another species.

Question 25

pros/cons of induced defenses

Answer 25

pros: less costly because it is only active when under attack.
cons: lag time between attack and when the defense is active, causing more harm to the host plant.

Question 26

delayed induced resistance

Answer 26

passive response, thought to be driven by alteration to carbon and nitrogen ratios. affects generations of insects subsequent to the one responsible for eliciting response. may have delayed density dependence effects. generally, needs severe defoliation

Question 27

numerical response

Answer 27

increased number of offspring in response to increased prey (food availability)

Question 28

density dependant population regulation

Answer 28

factors that have the same importance no matter the population size, mostly abiotic factors

Question 29

aggregate response

Answer 29

aggregate where there is more prey density

Question 30

bottom-up population control

Answer 30

availability, defenses, nutrients, phenology, ontogeny

Question 31

top-down population control

Answer 31

natural enemies, predators, parasites, parasitoids, pathogens

Question 32

ontogeny

Answer 32

study of plants changing nutritional quality over time

Question 33

types of natural enemies

Answer 33

pathogens, predators, parasites, parasitoids,

Question 34

types of plant anti-herbivory adaptations

Answer 34

chemical, mechanical, ecological, indirect, and tolerance

Question 35

classical biocontrol

Answer 35

reunite invasives with their natural enemy

Question 36

augmentative biocontrol

Answer 36

use of biocontrol agents that cannot be used in the long-term
- inoculative augmentation: enemy reproduces but does not persist without further introduction
- inundative: enemy stopped reproducing entirely

Question 37

conservation biocontrol

Answer 37

modify or preserve the habitat in a way that supports the natural enemies of the invasive species.

Question 38

risk assessment

Answer 38

weigh the potential costs of an action with the costs of not performing that action

Question 39

pros and cons of classical biocontrol

Answer 39

pros: huge return on investment in the case of the natural enemies being successful.
cons: huge chance of failure and it can be extremely risky if the natural enemy begins to target other species in the system.