While some ants are considered pests themselves, weaver ants from the genus Oecophylla are good pest controllers that actually help improve crop yields for farmers. According to a new review published in the Journal of Applied Ecology this week, these ants are the best documented example of biological control on open farms. Their efficiency rivals that of chemical pesticides, and they cost less too.
The idea of these reddish-brown ants acting as biocontrol isn’t exactly new, Science explains. About 1,700 years ago, farmers in China bought ants to release in citrus groves. Fast forward to 2008, when a study found that weaver ants eat and deter pests on farms so effectively (and cheaply), they upped net incomes by 71%. Thousands of farmers in Vietnam began turning to weaver ants to help them grow cashews.
To see if ants could be used as sustainable pesticides, Aarhus University’s Joachim Offenberg surveyed the scientific literature on ants as agents of what’s called “integrated pest management.” According to a suite of recent work, weaver ants can reduce pest numbers and the damage they cause – increasing the yields of multiple crops. Additionally, several studies found that ants are more cost effective than synthetic pesticides.
What’s more, weaver ants aren’t uniquely qualified to be pest control agents: they share these beneficial traits with almost 13,000 other species of ant. According to studies, other ant species have also demonstrated the potential for controlling arthropod pests, weeds, and plant diseases in orchards, forests and farms. Two European companies are now looking into providing weaver ant nests to farmers, Science reports, and a Danish aid project wants to establish ant nurseries in Africa that would provide mature colonies to interested farmers.