Beneficial Insects and Pests

In a cornfield in the Kham district in northeastern Laos, two black-and-red bugs use their proboscis to suck the life out of a small light-brown caterpillar. The caterpillar, a fall armyworm (Spodoptera frugiperda), causes devastating damage, particularly to corn crops. If detected too late, it is capable of destroying them. It also develops resistance to pesticides.

When the fall armyworm reached Laos in 2019 — likely from the Americas via Africa and India — it had no natural enemies in the country. A rapid response was needed: As part of a Swiss Agency for Development and Cooperation agricultural project and in collaboration with the Lao government, Helvetas quickly made informational materials and videos available to farmers via social media and urged them to search their fields for the pest as soon as the corn sprouts.

At the same time, the farmers tested and compared various control methods, such as manually removing the caterpillars, keeping chickens in the fields, and using various botanical extracts. It turned out that the use of bugs (Eocanthecona furcellata), which are distributed by hand onto the corn plants, is the second-most effective weapon against the fall armyworm. The most effective is a tobacco spray that farming families can produce themselves.

The project also helped the families diversify their crops. Thanks to this integrated pest management approach, through which corn farmers combine biological, chemical and physical methods, they are now able to keep the pest in check and even increase their corn yield.

Cattle urine and local plants

In Wag Hemra, in Ethiopia’s Amhara region, smallholder farmers are also turning to nature for pest control as part of a Helvetas project. The “enemies” there include grasshoppers, locusts and various types of worms. The “weapons”: various mixtures of cattle urine and extracts from over ten locally available plant leaves and fluids — such as tobacco, neem, aloe vera and garlic.

The farmers who have been trained in this technique now report noticeably healthier soil. “Combined with methods such as crop rotation and organic fertilizer, integrated pest management contributes to healthier ecosystems and improved soil fertility,” notes Desalegn Mamo, a senior agricultural development officer at Helvetas Ethiopia. And it protects pollinators.

According to the United Nations Environment Program, agriculture is the main reason more and more animal and plant species are disappearing worldwide. It threatens 86 percent of the 28,000 species at risk of extinction. In addition to pesticides, deforestation, monocultures and water consumption are particularly harmful. This makes methods that help reduce this impact all the more important.

Helvetas is not a nature conservation organization in the traditional sense; protecting the habitats of endangered species is not its specialty. However, since Helvetas works with people who depend on natural resources for their survival, the protection of biodiversity — directly or indirectly — is part of every initiative.

Invisible helpers

In northern Mozambique, smallholder farmers have reduced their pesticide use and increased their harvests with “effective microorganisms.” These are a mixture of bacteria and fungi, such as yeast and lactic acid bacteria, that positively influence microorganisms in the soil — similar to the fermentation process in yogurt or sauerkraut. They preserve soil life and improve soil structure. This naturally suppresses diseases and pests.

The “effective microorganisms” can also be sprayed directly onto the plants, where they displace disease-causing germs. “Thanks to them, farmers are less dependent on pesticides. In addition, the microorganisms attract pollinating insects,” explains Jeronimo C. Binda, a project coordinator at Helvetas Mozambique. This has opened new income opportunities for farmers through beekeeping.

Although the effectiveness of these microorganisms is still a subject of scientific debate, they have proven their worth in the Helvetas project when combined with other methods: The plants produce more flowers and absorb nutrients more effectively, which has a positive impact on crop yields. For example, the peanut harvest increased from 0.4 to one ton per hectare within seven years, and the cashew harvest from four to fifteen kilograms per tree. Biodiversity, as is evident everywhere, benefits both nature and people.