August 17, 2022 at 4:46 p.m.,
Updated on August 18, 2022 at 10:01 a.m.
Reading time: 2 minutes
Ants are more effective allies than pesticides in helping farmers protect the food they produce, according to the first study systematic study of the contribution of ants to agricultural production. And for good reason: they are responsible for killing parasites, reducing the damage they cause to plants and thus increasing crop yields.
To achieve these results, published in Proceedings of Royal Society B and relayed by The Guardian August 17, the researchers analyzed the presence of 26 species of ants – mainly arboreal – distributed on 17 crops – including citrus, mango, apple and soybean – in countries such as the United States, Australia, the UK and Brazil. The scientists compared groups of plants where these insects were present, to others where they were mechanically or chemically removed. Result: the greater the diversity of ants, the better it protects crops against a wider range of pests.
But then, how to encourage the presence of these Formicidae ? Researchers have found that these little beasts do better in diversified farming systems such as agroforestry — where trees and crops are grown together — and shade-grown crops, because they find more nesting sites and resources there. food.
Be careful, however, ants are not always a panacea. Their presence also encourages certain pests such as scale insects, aphids and whiteflies, which produce a sugary water called honeydew, and are generally more present when ants are around. Fond of this honeydew, the ants raise the aphids like cattle, protecting them in return from their predators. But according to the study, solutions exist, such as providing ants with an alternative source of sugars (on the ground, near the trunk of a tree or on its branches), which can deter them from raising aphids. .
Ants are more numerous than any other insect and represent the half of insect biomass of the planet. There are at least 14,000 known species of ants, and many more probably remain unknown. In China, citrus growers have been using them in their agricultural activities for centuries. These insects have also been used to control pests attacking forests in Canada, cocoa produced in Ghana and fields in Nigeria.