Chapter 7: Economic Decision Levels

Question 1

What is the concept of Economic-Injury Level

Answer 1

determines what all counts as a insect damage, how to measure damage, encourages more rational use of insecticides, avoids insecticide resistance

Question 2

Integrated Control

Answer 2

Replacement for only spraying insecticides, focuses on a well rounded approach

Question 3

Economic damage

Answer 3

amount of injury that will justify the cost of artificial control measures

Question 4

Injury

Answer 4

effect of pest activities on host physiology that is usually deleterious (pest activity focused)

Question 5

Damage

Answer 5

measurable loss of utility, often including yield quantity, quality, or aesthetics (crop/plant focused)

Question 6

when do insects become a problem

Answer 6

the money required for suppressing insect injury = potential monetary loss from the pest population

Question 7

gain threshold

Answer 7

beginning point of economic damage

Question 8

Damage boundary

Answer 8

lowest level of injury where damage can be measured - usually reaches before economic damage occurs

Question 9

Economic injury level

Answer 9

the lowest number of insects that will cause economic damage

Question 10

insect equivalents

Answer 10

the amount of damage one insect is doing through its entire lifespan

Question 11

EIL calculations

Answer 11

Cost of management per area, Economic impact level

Question 12

Economic threshold

Answer 12

the number of insects (density or intensity) that should trigger management action to prevent reaching the EIL

Question 13

Fixed economic threshold

Answer 13

percentage of EIL is fixed

Question 14

Descriptive economic threshold

Answer 14

takes into account possible changes in the pest population growth rate

Question 15

Market Value

Answer 15

Crop Value

Question 16

Management Costs

Answer 16

Cost of suppressing a pest population must be estimated before profitability of an action can be assessed

Question 17

Degree of injury per insect

Answer 17

Determined by insect and host plants

Question 18

stand reducers

Answer 18

insects that reduce stand (plant biomass)

Question 19

Leaf-mass consumers

Answer 19

insects that consume leaf matter, affecting photosynthesis

Question 20

Assimilate Sappers

Answer 20

piercing-sucking and rasping insects that remove plant nutrients before the plant can use it

Question 21

Turgor Reducers

Answer 21

soil insects and stem feeders, influence plant water and nutrient balances at the root and stem sites

Question 22

Fruit Feeders

Answer 22

Insects that injure fruit

Question 23

Architecture modifiers

Answer 23

insects that change plant morphology to reduce yield

Question 24

Crop susceptibility to injury

Answer 24

Relationship between injury and crop yield

Question 25

Amount of damage voided

Answer 25

expected proportion of the population killed by a management technique

Question 26

techniques to determine type and magnitude of plant response to insect injury

Answer 26

observation, modification of natural populations, creating artificial populations, injury simulation

Question 27

Nominal thresholds

Answer 27

decision rules that are declared on the basis of a managers experience

Question 28

Simple threshold

Answer 28

based on calculated EIL

Question 29

Comprehensive thresholds

Answer 29

decision levels still under development