#26 - Concept Reference, Strengthen

[Dave Killoran]

We received the following question from a student:

I’m confused. I choose c by process of elimination although it was a weak answer. The reason I didn’t choose e is because I put “they would be extinct.” (in handwritten note next to e)

It would be good that the typhlodromus tolerate the cold winters where the cyclamen notes are a lower population, but wouldn’t they just mean that the typolodromus would eat all the notes and therefore be a bad collateral damage on the typolodromus because they need them to survive? They cannot survive on honey dew forever!

Reference line 32: “they do not reproduce except when they are feeding on the cyclamen mites.

An instructor will answer this question soon!

[Jennifer Janowsky]

I’m confused. I choose c by process of elimination although it was a weak answer. The reason I didn’t choose e is because I put “they would be extinct.” (in handwritten note next to e)

It would be good that the typhlodromus tolerate the cold winters where the cyclamen notes are a lower population, but wouldn’t they just mean that the typolodromus would eat all the notes and therefore be a bad collateral damage on the typolodromus because they need them to survive? They cannot survive on honey dew forever!

Reference line 32: “they do not reproduce except when they are feeding on the cyclamen mites.

Thanks for your question!

Number 26 asks what option would most strengthen the authors argument--that predatory mites (typhlodromus) would be a viable pest control for strawberries.

You got stuck between (C) and (E), so let's review those.

Option (C) gave that in areas where there are pest mites (cyclamen), winters are also mild. As you said, the passage mentions predatory mites can subsist on honeydew when mite populations are too low in the winter. However, this doesn't seem to be an issue for the predatory mites. The passage already claims they show an "ability to survive" without prey and are described as "well-suited to exploiting the seasonal rises and falls of its prey." They don't seem to need mild winters, as they do just fine without them.

Option (E), however, is a different story. This option gives that the predatory mites do well in the same climates as strawberries are grown in. This would be great news for the author's argument--it would mean that wherever strawberries can grow, the mites could be employed as well. This makes them seem a viable alternative to chemical pest control, which would not need the right climate to survive. Similarly, predatory mites could be employed wherever strawberries are grown.

I hope that makes sense, thanks again for your question!

[HarryK]

2019 Bible Pg. 390 Typhlodromus

Hi,

When you explain question 26 choice (D), you say (D) does not strengthen the author's position. I agree with you; but I also thought that (D), if true, weakens his position. There seem to be only two possibilities in (D): spray parathion or not spray it. If not sprayed, then T has its predator, which makes T less apt to control C. If sprayed, then there is no T to control C in the first place; so T is not apt at all to control C. Thus, in both cases, the author's position (T controls C) is weakened. Please let me know whether this line of thought is correct.

Thank you,
Harry

[KelseyWoods]

Hi Harry!

I can tell you're definitely reading your RCB closely! Here are my thoughts on your thoughts:

I understand your thinking with answer choice (D) in question #26 but I'm not sure I agree that it weakens the author's position since I see the author's position as more of a relative one. The author argues that using predatory mites is a more effective means of controlling an agricultural pest than using pesticides. So even if Typhlodromus was sometimes preyed upon by another species of mite, it still might be a more effective means of controlling cyclamen mites than spraying with parathion. But, like you stated, it definitely doesn't strengthen the author's position, so the answer choice is incorrect.

Best,
Kelsey

[gingerale]

I narrowed down my choices to A and E and ended up choosing A. I thought that if individual mites with longer reproductive life spans were laying the most eggs, that would result in Typhlodromus overwhelming the cyclamen mite population even more and controlling the pest population with greater efficacy. In contrast, I ended up eliminating E from contention because I thought that it was implied in the passage in lines 27-37 and would thus not serve to strengthen the argument any further. Was I going too far in believing that was already implicitly stated in the passage? And why is A incorrect?

[Rachael Wilkenfeld]

Hi gingerale,

We want to start by thinking about what it is that we are trying to strengthen. Our question asks us to strengthen the author's position on practical applicability of the information on predatory mites. Let's start by thinking about what the author's position is.

The author's main argument here is that the predatory mites are an effective method of pest control for strawberry plants, possibly even more effective than pesticides. We want to help that argument, so we want something that tells us that these predatory mites will be effective for strawberry plants.

We already know information about answer choice (A). We know that the approximate possible ranges of eggs per reproductive predator is between 16 and 30 eggs. However, even if it were true that there were mites that hit the 30 egg mark, we don't know anything about the quality of those eggs, the frequency those mites reproduce, or any other information to provide strength to the author's argument.

Answer choice (E) however, does strengthen the argument by showing that the predatory mites are an option wherever strawberries grow. If they can survive in the same habitats, they can be used reliably for strawberry plants. While the passage discusses the predatory mites around some strawberry plants, answer choice (E) strengthens the argument by extending it to cover strawberry plants wherever they may grow.

Hope that helps!

[zoezoe6021]

Hello,

I narrowed it down to B and E, then chose B. After reading all the explanations in this thread, I understand why E is correct, but wondering whether B is wrong because it states that "kill both predatory and nonpredatory species of mites"

Thank you

[Dana D]

Hey ZoeZoe,

Yes, the issue with answer choice (B) is that it does nothing to support the author's point that predator mites are a practical way to control nonpredator mite populations on strawberries. If Answer Choice (B) was true, then insecticides typically used would kill both species of mites, but so what? The author is trying to tell us what would happen if we didn't use intestacies at all, and instead relied on a natural alternative of predator mites.