Aula 5 - Método de Controle - Biológico

Summary

This video discusses agricultural pest control, focusing on biological control methods. It explains the difference between abiotic and biotic pest regulation, with an emphasis on natural predators like insects, birds, and bats. Key techniques include using entomopathogens such as fungi, viruses, and nematodes for pest management. Historical milestones in biological control, such as the introduction of natural enemies to combat pests in various regions, are highlighted. The video also touches on the role of genetically modified organisms (GMOs) and transgenics in pest control and contrasts them with traditional biological methods. The importance of balancing ecological systems and the potential risks of introducing foreign species is also explored.

Takeaways

• 😀 Abiotic control of pests includes natural climate events such as rain and temperature variations that help regulate pest populations.
• 😀 Biotic control involves using living organisms, such as predators, parasitoids, and pathogens, to control pest populations.
• 😀 Biological control is when one organism regulates the population of a pest species, using natural predators like lizards, bats, and spiders.
• 😀 Entomopathogens, including fungi, viruses, and bacteria, are commonly used in biological control and tend to be pest-specific.
• 😀 Biological control differs from genetic modification, such as transgenic plants, which may contain pest-resistant genes but do not involve natural predator-prey interactions.
• 😀 The historical use of natural predators in pest control dates back to ancient China, where ants were used for controlling citrus pests.
• 😀 The introduction of the predator, Rodolia cardinalis, to California in 1888 to combat scale insects is considered a landmark success in biological control.
• 😀 Biological control methods like introducing parasitoids, such as Encarsia formosa, have been used in Brazil since the early 20th century.
• 😀 The use of chemical pesticides like DDT in the 1940s temporarily overshadowed biological control methods, but environmental issues and resistance led to a resurgence in biological control by the 1970s.
• 😀 The application of biological control in Brazil, especially with products like the Baculovirus anticarsia, has successfully managed pests like the soybean caterpillar since the 1970s.

Q & A

What is biological control in agricultural ecosystems?

Biological control refers to the use of natural organisms, such as predators, parasitoids, or pathogens, to regulate the population of pest insects. This process helps maintain the balance of species within an ecosystem without the need for synthetic pesticides.

What are the two main types of factors that control insect populations in nature?

The two main types of factors are abiotic factors, such as weather and climate conditions, and biotic factors, such as organisms like predators and parasitoids that regulate pest populations by directly affecting them.

Can you explain the difference between biotic and abiotic mortality in pest management?

Abiotic mortality is caused by non-living factors like climate events (e.g., temperature and rainfall), while biotic mortality involves living organisms, such as predators or pathogens, that kill pests or regulate their populations.

What are some examples of organisms used in biological control?

Examples include predators like ladybugs, spiders, and geckos, as well as entomopathogens like fungi, viruses, and bacteria. These organisms target and control pest populations in agricultural systems.

How do entomopathogens help control pest populations?

Entomopathogens are pathogens like fungi, viruses, and bacteria that infect and kill pest insects. They are often specific to certain insect species, ensuring that only the target pests are affected, which helps reduce their numbers.

What is the role of nematodes in pest control?

Nematodes are microscopic worms that can be used as biological control agents to target soil-dwelling pests, such as beetles, weevils, and larvae. They infect and kill pests, particularly those that live in the soil.

Why is it incorrect to refer to genetically modified (GM) plants as biological control agents?

GM plants are not considered biological control agents because they do not involve natural predator-prey interactions. Instead, GM plants contain genetic material from bacteria that produce toxins, which is a different process from natural biological control.

What is an example of the successful application of biological control in history?

A well-known example is the introduction of the ladybird beetle (Rodolia cardinalis) in California in 1888 to control the cottony cushion scale, a pest that was damaging citrus crops. The introduction of this predator was highly successful and marked a turning point in the use of biological control.

What is the historical significance of biological control in Brazil?

Biological control in Brazil began in the 1920s, with the introduction of parasitoid insects like Encarsia formosa to control whitefly populations. Over time, biological control expanded, especially with the use of natural enemies for pests in crops like soybeans and tomatoes.

What is the difference between classical biological control and conservation biological control?

Classical biological control involves introducing natural enemies from other regions to control pest species, while conservation biological control focuses on creating or maintaining favorable conditions for natural enemies that already exist in the ecosystem, such as planting attractive plants for beneficial insects.