Self-study
P1
Sometimes there is no more effective means of controlling an agricultural pest than giving free rein to its natural predators. █ ████ ██ █████ ██ ███ ████████ █████ █ ████ █████ ██████████ ███ ██ ███████████ ██████████ ██ █ █████████ ████ ██ ███ █████ █████████████ ███
Intro topic ·
Controlling cyclamen mites using Typhlodromus mites
Problem ·
Infestation of strawberry plants by cyclamen mites
Solution ·
Typhlodromus mites
Attack in second year of infestation, when cyclamen mite populations reach damaging levels
P2
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Introduce explanation ·
Several reasons why Typhlodromus is a good solution
Reason 1: Voracious appetite
Reason 2 ·
Typhlodromus population grows as quickly a cyclamen's
Both reproduce by parthenogenesis
Reasons 3 and 4 ·
Reproductive timing and alternative sources of food
Reason 3: Typhlodromus only reproduces when cyclamen prey is available.
Reason 4: Typhlodromus has other food sources, allowing it to survive when cyclamen mites are scarce.
Draw similarity ·
Typhlodromus is similar to other predators that control prey
Because of reasons 1-4
P3
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Support solution ·
Experiments correlate presence of Typhlodromus with lower cyclamen populations
P4
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Implications of experiment ·
Pesticide use can cause more harm than good...
...if pesticides kill predators like Typhlodromus
Reinforce implications ·
Where pesticide (parathion) used, Typhlodromus absent and cyclamen populations higher
Again, correlation between presence of Typhlodromus and lower cyclamen populations
Passage Style
Problem-analysis
Single position
27.
Information in the passage most ████████ ████████ █████ ███ ██ ███ █████████ ███████████
a
Strawberry crops can ███████ ███████████ ██ ████ ████████ █████ ███ ████████████ █████ ███████ ███████████ ██████ ██ █████ ██████
Supported, because we’re told that T-mites can
b
For control of ████████ █████ ██ ███████ ████ ███████ ██ ██ ██████████ ██ ██ ███████ ████ ███ ███ ███████ ████ ███ ████ ████ ██ █████████████
Not supported, because we have no reason to think the predatory mite needs to lay eggs just like the C-mites lay eggs. What matters is the synchronicity of the reproduction. We want the predator mite population to go up when the C-mite population goes up. But whether the predators use eggs doesn’t matter.
c
Factors that make ████████████ █████████ ███████ ████████ █████ ████ ████ ██ █████████ ███████ ███████ █████ █████ ██ ██████████ ███████
The author never mentions T-mites’ effectiveness against other kinds of pests besides C-mites.
d
When Typhlodromus is ██████ ██ ██ ███████ ████████ █████ ██ ██████████ ██████ ██████████ ███ ██ █████████ ██ ███████ ███████████ ██████ ██████ ███ █████ █████
Not necessary, we’re told
e
Strawberry growers have ███████████████ ██████ ████████ █████ ██ ██████ █ ███████ ████ ████ ██ ███ ██████████████ ███ ██ ██████████
Not supported, because we don’t know whether strawberry growers use parathion outside of the experiments and observations described in the passage. We’re never told that parathion is typically used on strawberry plants. And even if they do, we don’t know that they use parathion “indiscriminately.” Maybe they do try to be careful about where parathion is sprayed, but sometimes accidentally spray where they don’t want to.