Test 3 Flashcards
describe insecticide resistance
a heritable change in the sensitivity of an insect pop to insecticides reflected in the failure of that insecticide to achieve the expected level or control
insecticide resistance is _______ driven by _______
population evolution driven by natural selection
can resistance evolve to any management tactic that causes high mortality and/or reduced natality
yes
describe cross-resistance
development of resistance to one insecticide confers resistance to another insecticide
what does the rate of resistance depends on
-frequency of application
-level of insecticide-induced mortality
-genetics (monogenic vs. polygenic)
-reproductive and development rate
does increase pop isolation lead to higher or lower insecticide resistance
increased rate of insecticide resistance
does insecticide resistance evolve faster in monogenic or polygenic genes
polygenic will take longer to evolve because resistance involves multiple genes
describe metabolic resistance
resistant insects can destroy or excrete the toxic compound faster than susceptible ones
describe target-site resistance
a change in structure of the target protein that decreases herbicide binding to its usual site of action
describe penetration resistance
the insect will absorb insecticide slower and therefore will receive a smaller dose
describe behavioural resistance
insect will stop feeding or leave an area when it comes across an insecticide
-behavior needs to have a genetic basis
Name 4 resistance mechanisms
- metabolic resistance
- target-site resistance
- penetration resistance
- behavioral resistance
why is the colorade potato beetle so bad?
its resistant to at least 56 insecticides and has every type of resistance mechanism
why is the Colorado potato beetle so insecticide resistance
it feeds on solanaceous plants which have compounds that are like insecticides so its adapted to deal with insecticides
name 6 ways we can manage resistance
- practice IPM
- follow economic thresholds
- target most susceptible life stage
- apply according to the label
- rotate different MOAs
- preserve susceptible genotypes (field refuges)
describe toxicology
study of adverse effect associated with exposures to substances
describe toxicity
the inherent poisonous potency of a substance (relative to other stuff)
what is a fundamental concept of toxicology (paracelsus)
the dose makes the poison
what’s the difference between acute, subchronic, and chronic toxicity
acute: very short term exposure (24-48h)
subchronic: short term exposure (3-6m)
chronic: long-term exposure (2-4 yrs or more)
what is an LD50
does that will kill 50% of the pop you are testing on
does a lower LD50 mean the substance is more or less toxic
lower number means it takes less of it to kill you or cause an effect
what is ED50
dose that would produce the effect of interest in 50%
what is EC50
concentration that would produce the effect of interest in 50%
what is LC50
concentration that would kill 50%