We all know that conventional pesticides are associated with a lot of harmful side effects. Farming on a commercial scale requires high crop yield, which pesticides help to produce. As the world’s population is set to hit eight billion people by 2022, finding ways to grow crops quickly with minimum wastage is a necessity.
Now, a team of scientists from institutions in Brazil and Spain have found that ants can be even more effective at protecting crops from pests than conventional harmful pesticides. The researchers, led by Diego V. Anjos, looked at over 50 studies over 17 different crops. The crops were grown in the UK, US, Australia and Brazil, and included cotton, mango, cauliflower and sweet potato.
After analyzing the papers, the researchers discovered that ants were as good, if not better in some cases, at protecting crops from pests.
“Overall, the mere presence of ants, regardless of their body size, provided pivotal services for crops,” the researchers said in their study.
The ants’ presence was most effective when they were in shady areas. In areas protected by shade, ants decreased pests by almost twice as much. Ants were also more effective when the crop range was diverse- i.e. when many different types of crops are grown together.
However, ants did increase the presence of one insect- aphids. Ants actually farm aphids to capture the sweet honeydew that they secrete. Whilst aphids may have been increased, the overall effective of using ants as pest control is positive. The researchers also suggested that having another source of sugar nearby could negate the effects of aphids.
The use of ants in pesticides is not a new concept. In China, ants have been used to control pests in citrus trees for centuries. The yellow citrus ant was documented 1700 years ago as being used to control pests in the orange groves of Southern China. And it’s not just ants that have been used as natural pesticides. Ducks have been used by farmers in Thailand to devour pests.
Harmful effects of pesticides
Globally we use 2.5 billion kilograms of pesticides every year. Pesticides have been blamed for a myriad of health conditions, affecting the nervous system, skin and eyes, and being strongly linked to different types of cancer.
Pesticides also have detrimental effects on other insects, particularly bees, which are necessary for pollinating a third of crops grown for global food production. A study recently revealed that pesticides impair bees’ ability to fly in a straight line, and effects their homing ability. Bees exposed to pesticides also had a higher incidence of brain cell death.
Moving away from traditional pesticides would have a myriad of positive benefits for humans and insects alike. The researchers concluded their article by stating that ants would also be cost-effective compared to chemical pesticides, and would help to maintain low biodiversity.