Do you drink coffee? A lot of people do—coffee is a major tropical crop, valued at over \$100 billion per year. The most popular species of coffee, Coffea arabica, originated in Africa and is now planted extensively in Central and South America. The pest called the coffee berry borer beetle (Hypothenemus hampeii) moved along with the coffee and is a major problem for coffee farmers, sometimes destroying half of the coffee crop in mature plantations.
Look at the graph. Why did the researchers bother to collect data from the coffee shrubs before adding the nets to treatment plots to exclude birds?

Verified step by step guidance

1. The researchers collected data from the coffee shrubs before adding the nets to establish a baseline measurement of the percentage of berries with borers in both control and treatment plots.
2. By having baseline data, researchers can compare the percentage of berries with borers before and after the nets are installed, allowing them to assess the impact of bird exclusion on borer infestation.
3. The graph shows that before the nets were installed, the percentage of berries with borers was similar in both control and treatment plots, indicating that any differences observed after net installation can be attributed to the exclusion of birds.
4. After the nets were installed, the treatment plots (where birds were excluded) showed a significant increase in the percentage of berries with borers compared to the control plots, suggesting that birds play a role in controlling borer populations.
5. Collecting data before the intervention helps to ensure that any observed changes in borer infestation are due to the experimental treatment (bird exclusion) rather than pre-existing differences between the plots.

Key Concepts

Coffee Berry Borer Beetle

The coffee berry borer beetle, scientifically known as Hypothenemus hampeii, is a significant pest affecting coffee crops. It burrows into coffee berries, leading to substantial crop loss, sometimes up to 50%. Understanding its life cycle and behavior is crucial for developing effective pest management strategies in coffee farming.

Exclusion Nets

Exclusion nets are physical barriers used in agriculture to protect crops from pests, particularly birds and insects. In the context of the study, these nets were installed to determine their effectiveness in reducing the percentage of coffee berries infested by the coffee berry borer beetle. Analyzing data before and after net installation helps assess their impact on pest populations.

Control vs. Treatment Plots

In experimental research, control plots are used as a baseline to compare against treatment plots, which receive the experimental intervention—in this case, the exclusion nets. By collecting data from both types of plots, researchers can evaluate the effectiveness of the intervention in reducing pest infestation and understand the dynamics of pest populations in relation to environmental factors.