Most insecticides from the neonicotinoid group have been banned for large-scale use in agriculture for a number of years. This is because these insecticides are very toxic to bees and bumblebees. They are also toxic to soil organisms such as earthworms and springtails, as was shown in previous research by the VU.
The use of acetamiprid is still allowed. However, a new study by eco(toxico)logists Kees van Gestel (VU Amsterdam), Michella Ligtelijn (University of Groningen, former master's student at VU) and Henrik Barmentlo (University of Leiden) shows that this substance does break down quickly, but does pose a risk to soil organisms. The article was published in Environmental Pollution.
Soil disbalance
The researchers conducted tests in the CLIMECS laboratory of the VU, in mesocosms: a kind of mini-ecosystem with a grassland soil. Acetamiprid turned out to be very toxic for springtails, which decreased in number. These effects already occurred at quantities that end up in the soil during normal agricultural use. Other soil animals, mites, turned out to be hardly sensitive to the substance and actually increased in number. Such differences can cause the ecosystem in the soil to become unbalanced.
Recovery
After 54 days, the system seemed to be recovering. However, the researchers point out that the agent is often used annually in agriculture and may be applied up to three times within one growing season (crop cycle). In addition, other agents are also used in agriculture. The effects of these combined agents are still unknown.