Although you may be terrified of them, common, social wasp species could help keep our crops pest-free, reports a new study.
The blue and black predators can act as solid pest control for at least two high-value crops: maize and sugarcane. While the experiment was carried out in Brazil, the team explains that wasps are found virtually all over the world and can easily be 'recruited' on small or large-scale farms to control a range of common pest insects.
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"There's a global need for more sustainable methods to control agricultural pests, to reduce over-reliance on pesticides or imported pest controllers. Wasps are very common, but understudied, so here we're providing important evidence of their economic value as pest controllers," said the study's lead author, Dr. Robin Southon from University College London's (UCL) Centre for Biodiversity & Environmental Research.
The study was carried out in Brazil with the help of researchers at São Paulo State University and Universidade de São Paulo; the team explains that it is the first controlled experiment in semi-natural conditions on the subject, as it was performed on an outdoor research site. The maize crops used in the study were infested with fall armyworms, while the sugarcane crops were infested with sugarcane borers. As a pest control, the team used the social paper wasp, a hunting wasp common to the area.
All in all, the wasps seem to have been effective. Their presence reduced the pest populations and led to the crops suffering less damage. The team further found that even pests which already bored inside the plants (and weren't present on their surfaces) were removed by the wasps.
The findings definitely suggest that the wasps have potential as pest control agents and could be used as part of a larger, integrated pest management mechanism. The team is especially excited for their use as wasps are native species and naturally part of many ecosystems today, which would make them a much more sustainable and environmentally-friendly alternative to today's pesticides. Not only that, but the insects can also be a "cheap, accessible form of pest control, particularly helpful to small-scale or subsistence farmers in countries like Brazil, who could attract and encourage wasps to establish themselves," according to co-author Professor Fabio Nascimento, who hosted the study at his labs in São Paulo State University.
The team plans to continue their research using larger, active agricultural fields. Wasps today are in decline across the world, similarly bees. The team notes that wasp loss can lead to a sharp increase in aphids, flies, and other species they prey on.
"This isn't just about agriculture—this is about wasps in general and their role in regulating insect populations," says Dr. Seirian Sumner (UCL Centre for Biodiversity & Environment Research), the study's senior author. "Even your backyard garden could benefit from a more wasp-friendly attitude—instead of killing wasps and using pesticides on your plants, treat your local wasps as the helpful pest controllers they are."
The paper "Social wasps are effective biocontrol agents of key lepidopteran crop pests" has been published in the journal Proceedings of the Royal Society B: Biological Sciences.