Environnement - Pesticides

Biocontrol: a sustainable alternative to chemical pesticides

Biocontrol uses natural enemies to manage pests, offering a promising solution for protecting crops while preserving biodiversity. This article explores the benefits, drawbacks, and future of biocontrol in Lebanon. This short blurb highlights the key points of the article and its relevance to Lebanon.

When we talk about agriculture, we often think about the use of chemical pesticides. While these substances are effective in boosting production and ensuring food security, they come at a cost; their well-documented impacts on biodiversity and public health raise serious concerns. Yet, their widespread use persists, both locally and globally.

What if the solution was in nature itself? Is there a more nature-friendly way to manage crop pests, ensuring a good yield while also adhering to organic farming standards?

What is biological control?

Biological pest control, also known as biological control or natural control, is the use of natural ways to control the populations of unwanted crop pests. This approach is part of the Integrated Pest Management strategy (IPM), promoting ecological ways in the development of agriculture. It primarily employs insects but can also involve other animals, or even bacteria and fungi.  The aim is to use the natural enemies of unwanted organism, which can include predators, parasitoids, and pathogens. The species used to control the pest are referred to as “biological control agents.”

This practice has a rich history, dating back to 324 BC when Chinese farmers were recorded using ants to feed on citrus pests. Biological control then resurfaced in the 1870s in the form that we know today. Later in 1905, the U.S. Department of Agriculture (USDA) started the first large-scale program of using biological control agents in agriculture. Despite its ancient roots, this method has undergone great improvements in the last decades, evolving into an effective substitute of toxic pesticides.

Control not eradicate

The goal of biological control is not to completely eradicate the pest but rather reduce its population down below economically damaging levels. This helps bring balance in the planted fields without causing the extinction of native species that are otherwise important for the ecosystem. Because yes, even though these species are considered as crop pests, they still play a vital role in nature, and suppressing them entirely would cause irreversible ecological damage. After all, it’s the whole point of using this method instead of pesticides, no?

Three primary methods help achieve this balance:

Conservation: This method seeks to conserve the natural enemies of the pest in their native habitat, helping them maintain a significant population that can target the pest.

Classical: In this case, the control agent is introduced to regions where it doesn’t naturally occur. Careful selection of the species ensures they don’t become invasive and threaten native species present in the ecosystem.

Augmentation: Existing native populations are enlarged and boosted to enhance their effectiveness in controlling the pest populations.

Different biological control agents

Ladybugs and lacewings are both fierce predators that consume a large number of aphids (the prey in this case) during their lifetime. These species are some of the most commonly used agents to control aphid infestations on fruit trees. They are also readily available and easy to attract. Who hasn’t seen them in their garden?

Parasitoids, on the other side, are species that lay eggs on or inside the pest insect. The larvae then grow on the surface or within this host, eating and ultimately killing it. Many species of wasps and flies are parasitoids.

Pathogens are disease causing organisms that weaken or kill their host. These include bacteria, fungi, and viruses that are specific to certain insect groups.

Benefits and drawbacks 

Biological control offers important social, environmental, as well as economic benefits. It is an environmentally friendly way to manage pests that can become self-sustaining over time, integrating seamlessly into the natural balance of the control area. However, it also has drawbacks. Unlike chemical pesticides that are relatively cheap and work within minutes to hours of application, biological control requires significant time to implement, and a great financial investment in the research of agents that are the most effective in each case.

Another possible risk is the accidental introduction of invasive species, mainly in the case of classical biological control (explained above). These insects would attack non-target species and compete with native species, causing harm to the habitat and the ecosystem.

And where are we in all this?

You may not have heard much about this topic in the local media, but Lebanon also has its share in this innovative method. Some Lebanese farmers and agricultural engineers have already adopted biological control methods locally, with notable success. This shift toward eco-friendly and sustainable agriculture marks a promising future for Lebanon’s food security and environmental conservation efforts.

Biological pest control has a promising future in the world, but also specifically in Lebanon, where the need for ensuring food security is an increasingly important matter, while we also need to avoid causing more damage to our environment.