Jordan has an organic garden. He is designing an experiment to determine if a mineral-oil bug spray made of garlic and habanero peppers is more effective on Japanese beetles than one made with just garlic. How could Jordan improve his plan for the experiment as outlined below? (2 points)
Prepare bug sprays, being sure to document ingredients in each type
Determine which plants will be sprayed and section off two groups
Spray every morning at 8:30 am
Record number of beetles on each group at the same times every day
Record significant rain or weather events that may affect application of the sprays
Photograph damage on both groups of plants at the end of the trial

He should include a control group which receives no spray.
He should remove all living beetles after each counting.
He should account for all the beneficial insects he accidentally kills.
He should prepare several variations on each spray's recipe.

Question

Jordan has an organic garden. He is designing an experiment to determine if a mineral-oil bug spray made of garlic and habanero peppers is more effective on Japanese beetles than one made with just garlic. How could Jordan improve his plan for the experiment as outlined below? (2 points)
Prepare bug sprays, being sure to document ingredients in each type
Determine which plants will be sprayed and section off two groups
Spray every morning at 8:30 am
Record number of beetles on each group at the same times every day
Record significant rain or weather events that may affect application of the sprays
Photograph damage on both groups of plants at the end of the trial

He should include a control group which receives no spray.
He should remove all living beetles after each counting.
He should account for all the beneficial insects he accidentally kills.
He should prepare several variations on each spray's recipe.

Vocaloid · Answer

Old question, but I'll respond to help out anyone who also finds this question

In general, for an experiment, you always want a control group that does not receive experimental treatment. In this case, the control group would have no spray. This lets us compare both treatment groups to a baseline control group. Additionally, by adding a control group, we eliminate the possibility that neither experimental treatment makes a significant difference (hypothetical: let's say we add a control group and we discover that there is no significant difference between the sprayed vs. control, regardless of ingredient)

Explanation for why the other ones are wrong:
He should remove all living beetles after each counting. ---> incorrect. he needs to keep the beetles in to make sure that the beetles are only dying due to the spray and not due to beetle removal

He should account for all the beneficial insects he accidentally kills. ---> incorrect, as this is not relevant to his experimental goals

He should prepare several variations on each spray's recipe. ---> incorrect, as he is only interested in the effect of adding habanero.