First, give yourself three minutes to read this article:

Olive trees, which are a critical component of Mediterranean agriculture, are threatened by a bacterium which causes a disease called quick decline syndrome (QDS). This bacteria can quickly destroy the trees and has already devastated entire olive groves in Italy and Spain. There are several methods to protect olive trees from QDS, but the following three are widely considered to be the most effective.

Early detection of the bacteria is critical to preventing the spread of the disease. Farmers should regularly inspect their trees and look for signs of disease, such as yellowing and withering leaves, dying branches, and slow growth. If a tree shows signs of infection, it should be immediately removed and burned to prevent the spread of the bacterium to other trees. The government and agricultural organizations can also play a significant role in early detection by encouraging farmers to take part in this strategy.

Promoting the overall health of olive trees is another effective strategy to prevent the spread of the bacteria. Trees that are in good health are better equipped to resist infections and recover from diseases. Proper irrigation, fertilization and trimming are all essential for promoting tree health. Farmers can also plant saplings that have shown some genetic ability to resist Xylella this disease.

Since the bacteria is transmitted to olive trees by sap-sucking insects, mainly the spittlebug, reducing the populations of such insects is crucial in controlling the spread of the disease. The most effective method farmers can use to control insect populations is spraying chemical insecticides. An additional strategy is to introduce natural predators of the insects, such as ladybugs, lacewings, and wasps, which can help reduce their populations over time.

Next, listen to the following lecture:


You have twenty minutes to answer the following question.  You can refer to the article as you write your essay.  You may not listen to the lecture again.

Summarize the points made in the lecture, being sure to explain how they cast doubt on the solutions presented in the reading passage.

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Sample Response

The reading and the lecture are about quick decline syndrome, a disease that affects olive trees.  The professor suggests three solutions to this problem.  Meanwhile, the lecturer challenges each of the solutions.  He believes that they won’t save olive trees.

First, the author argues that early detection of the virus is key to stopping it.  According to the article, farmers can watch for diseased trees and immediately destroy them before the virus spreads to other trees.  The government can encourage them to do this.  The lecturer challenges this suggestion.  He says that constantly inspecting trees is expensive and time-consuming.  Moreover, by the time we spot a diseased tree the virus has already spread to other trees.

Next, the author says that promoting the overall health of olives trees is an effective solution, as they are more able to resist diseases.  This can be done through proper trimming and irrigation, and also through planting saplings that are designed to resist the virus.  The lecturer calls this into question as well.  He notes that this won’t guarantee protection, as even healthy trees can become infected.  He also notes that genetically resistant saplings can be very expensive for farmers to purchase.

Finally, the article suggests spraying insecticides to stop the virus, as it is often spread by insects like spittlebugs  Natural predators like wasps and ladybugs can also be used to control their populations.  The lecturer, however, says that insects gradually adapt to insecticides so they won’t help in the long run.  Not only that, but natural predators might just fly away to a place where they aren’t needed.  It is hard to tell when this has happened, since olive groves are in rural areas.