Quote:
A commercial insect trap consists of a small box containing pesticide mixed with glucose, a sweet substance known to attract insect pests. Yet in households where this type of trap has been used regularly for the past several years, recently installed traps are far less effective in eliminating insect pests than were traps of that type installed several years ago. Research scientists have hypothesized that traps in those households decreased in effectiveness because successive generations of the pests developed a resistance to the pesticide in the traps.
Which one of the following, if true, most seriously undermines the hypothesis?
Commercial insect trap is effective when glucose attracts pests and then pesticide kills the pests.
If pests have not developed resistance to the pesticides then they might have developed dislike for the glucose, thereby lowering the effectiveness of trap.(A) In households where the traps have been used regularly, the proportion of insect pests that have a natural aversion to eating glucose has increased with each successive generation.
This describes with each generation pests aversion has increased, so they are no more attracted to these traps.(B) Even when only a few individuals out an entire generation of insects survive the effects of a pesticide, the offspring of those individuals are usually resistant to that pesticide.
How the offspring builds resistance is not relevant to the reasoning(C) After eating glucose mixed with the pesticide, insects that live in households that do not use the trap tend to die in greater numbers than do insects from households where the traps have been used regularly.
This indicates another reason for pest deaths but this does not explain whether effectiveness of these traps are reduced.(D) After the manufacturer of the traps increased the concentration of the pesticide used in the traps, the traps were no more effective in eliminating household insect pests than were the original traps.
increased dosage of pesticides highlights the strong resistance of these pests. This strengthens the argument (E) The kind of glucose used to bait the traps is one of several different kinds of glucose that occur naturally.
This is not relevant to the reasoningAns: A