Thursday , June 17 2021

Research: Biological control of insects protects tropical forests –

Although often perceived as an environmentally risky practice, biological control of invasive species can restore crop productivity, relieve soil pressure and contribute to forest conservation. This paper illustrates the positive impacts of biological control using manioc cochineal Phenacoccus manihoti (Hemiptera) as an example. Cassava is one of the major food, feed and fiber crops grown in about 4 million ha in tropical Asia, where the use of a parasitic wasp reduces crop losses, restores farm profitability, and reduces deforestation.

During the period 2009-2010, the invasive cochineal caused an 18% decline in cassava production in Thailand, leading to marked increases in cassava prices and stimulating a regional expansion of cassava acreage. This coincided with 185-608% increases in peak deforestation rates in neighboring countries. After release of the host-specific parasitoid Anagyrus lopezi (Hymenoptera) in 2010, cochineal outbreaks were reduced, cultivated area was contracted and the rate of deforestation declined by 31-95% in individual countries. Thus, when used according to established guidelines, biological control of a crop pest can avoid the need for synthetic pesticides, protect tropical biodiversity, and provide lasting environmental benefits on a macroscale.

Insects provide invaluable services to mankind, including natural pest control, a service worth at least $ 4.5 billion annually for US agriculture alone. This week's study in Biology of Communications reveals how a carefully selected pest killer insect – a tiny parasitic wasp – helps solve invasive pest problems, increases crop productivity, and protects tropical biodiversity. "Biological insect control reconnects insect friends and enemies and restores ecological balance in invaded agroecosystems," says Kris Wyckhuys, an agroecologist at the University of Queensland (Australia) and IPP-CAAS (China) and coordinator of the study. "These nature-based approaches provide a & # 39; win-win & # 39; which addresses the mitigation of invasive species, conservation of biodiversity and profitable agriculture. Collaboration between conservation biologists and pesticide scientists can thus be beneficial in balancing the realities of farmers in the field with biodiversity conservation. "

The study underscores the broad environmental benefits of biological insect control as a desirable alternative to insecticide-based approaches to pest problems, supporting sustainable intensification and saving land for conservation. "It is often difficult to reconcile socioeconomic and ecological issues, and small farmers are regularly tempted to resort to costly and environmentally harmful chemical pesticides to control pests. This study confirms that the appropriate use of biological control can solve socio-economic, environmental and ecological issues simultaneously, especially in tropical countries, "adds Jean-Philippe Deguine, an agroecologist and entomologist at CIRAD and co-author of the paper. By opting for biological control, farmers disarm pest problems, increase the profitability of their operations and, at the same time, become stewards of the environment.

Agroecological Protection of Cultures, a way to preserve biodiversity in the tropics

When used with established safeguards, biological control can permanently solve problems of invasive species. The scientifically oriented introduction of specialized natural enemies to provide pest control services in field crops is in line with the agroecological protection of crops. As an economical alternative to pesticide-based approaches and relying on the services of nature to suppress agricultural pests, the agro-ecological protection of plantations aims at restoring and optimizing ecosystem functioning and helps to ensure that crop protection benefits the pockets of farmers, health of consumers and producers and the broader agricultural environment.

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