Talk:Desert locust (Schistocerca gregaria)

Insecticide Use against Desert Locust in the Horn of Africa 2019–2021 Reveals a Pressing Need for Change

The Horn of Africa experienced a significant desert locust upsurge from 2019 to 2021, posing a severe threat to agriculture and food security in the region. The study by TMG Research "Insecticide Use against Desert Locust in the Horn of Africa 2019–2021 Reveals a Pressing Need for Change" published in Agronomy examined the extensive use of chemical insecticides in Ethiopia and Kenya, and the pioneering large-scale application of biopesticides methods in Somalia.

During this period, approximately 1.6 million hectares across Ethiopia and Kenya were treated with broad-spectrum organophosphate and pyrethroid insecticides. This response raised significant environmental concerns. In Kenya, the overdosing of fenitrothion (960 g/L formulation) resulted in the unintended mortality of non-target species, including birds and honeybees. In Ethiopia, the use of chlorpyrifos and malathion coincided with a drastic 78% decline in honey production in 2020, compared to levels before the locust upsurge.

A critical issue identified in the study was the lack of environmental monitoring during the upsurge. Only limited surveys were conducted in Kenya and Ethiopia, which were insufficient to fully understand the ecological impact of the chemical insecticide use.

Importantly, Somalia was the only country in the region to apply the entomopathogenic fungus Metarhizium acridum and insect growth regulator teflubenzuron. The use of M. acridum (50g per liter and 1 liter per ha) on nearly 253,000 ha was a breakaway from previous campaigns. Its successful large-scale application against both hopper bands and swarms proved the viability of sustainable, environmentally friendly alternatives, making the persistent and pervasive use of organophosphate insecticides untenable.

The researchers also recommended an integrated management approach that considers the complementary impact of biological control agents like M. acridum and natural predation by birds. Avian predators play a crucial role in locust population control, particularly post M. acridum treatment. Unlike with chemical pesticides that harm bird populations and therefore weaken natural control and resilience, M. acridum and bird predation are fully compatible and complement each other. Locusts infected with fungus become sluggish and move up in vegetation to bask in the sun, exposing them to predators. This approach could offer a more sustainable and ecologically sound solution for controlling both locust swarms and hoppers.

The study also pointed out that the future procurement of organophosphate insecticides and possibly insect growth regulators may face challenges due to regulatory measures by the European Union (EU). To illustrate, chlorpyrifos is banned in both the EU and the U.S. This trend towards stricter pesticide regulations further underscores the need for alternative locust control strategies.