This provides an alternate explanation for the decreased effectiveness of the traps. The glucose in the trap is not as attractive anymore, which means fewer insects enter the traps. This results in decreased effectiveness, even if the insects aren’t resistant to the pesticide.

If anything, this answer supports the author’s theory by showing resistance can develop in offspring even if one generation is almost entirely wiped out.

If anything, this could support the author’s theory by showing that in households where insects haven’t had the chance to build up resistance, the trap is more effective than in households that have used the trap for several years.

This is consistent with the author’s hypothesis. Increased concentration of the pesticide should make the trap more effective. Just because the traps didn’t become more effective than the original doesn’t mean they didn’t become more effective.

The fact the glucose occurs naturally doesn’t have any impact. Does natural glucose have anything to do with the traps’ decreased effectiveness? We have no reason to think so.