Passage Summary: These bug traps aren't working like they used to. Scientists think the bugs have evolved to be immune to the poison inside.

Conclusion: The reason the bug traps are less effective now is that the insects have developed a biological resistance to the pesticide.

Reasoning: Traps of the same design were much more effective in the same households several years ago than they are today.

Analysis: To weaken this hypothesis, we need to find an alternative reason why the traps are failing that has nothing to do with the bugs' immunity to the poison. The trap relies on two things: attracting the bug with sugar (glucose) and then killing it with pesticide. If the bugs have evolved to stop liking the sugar, they'll never touch the poison in the first place, which would explain the trap's failure without requiring any pesticide resistance. Look for an answer that suggests the bugs' behavior toward the bait has changed or that some other external factor is interfering with the trap's success.