PrepTest 124, Section 4, Question 26

Working the answers

• A

  This connects two reproductive traits among individual predators. It doesn't establish that the mites can be used successfully in the relevant growing conditions. We already have evidence that their populations can reproduce rapidly.

• B

  This describes insecticides that kill the pests as well as their predators. Unlike parathion in the experiment, these chemicals could directly control the pests. That doesn't strengthen the practical case for relying on the predatory mites.

• C

  Mild, short winters don't tell us what conditions Typhlodromus can tolerate. The account already gives a way they survive winter food shortages. Without a connection between the climate and the predators' ability to function, C leaves the practical question open.

• D

  This introduces something that eats Typhlodromus. Its susceptibility to parathion doesn't solve the problem: parathion kills Typhlodromus too. It doesn't show that we can protect our useful predator through that treatment.

• E
  Correct

  This directly connects the predator's tolerance to the crop's growing conditions. If Typhlodromus tolerate the same climates as strawberry plants, they can survive where their pest-control service is needed. That removes a practical obstacle to applying the information beyond the observed plots, without promising that every use will succeed.