University of Reading. “Air pollution threatens natural pest control methods in sustainable farming: Controlling aphids with parasitic wasps is more difficult in polluted environments..” ScienceDaily. ScienceDaily, 9 November 2022. <www.sciencedaily.com/releases/2022/11/221109085816.htm>.
A recent study led by a team of scientists from the University of Reading tested the effect of diesel exhaust and ozone to oilseed rape plants, and the reproductive success of parasitic wasps in relation. The study used special equipment to apply controlled amounts of diesel exhaust to the plants; they also added aphids, an insect that is quite harmful to crops. It is important to note that parasitic wasps reproduce by laying their eggs in a stung aphid, and effectively controlling the aphid population whilst maintaining their own.
The study found that even while using exhaust levels that were lower than the ones set by environmental regulators, the number of parasitic wasps decreased. The wasps had difficulty finding aphids to prey on when the oilseed rape plants were in conjunction with diesel exhaust and ozone; the population of the wasps consequently fell. This new finding is worrying to sustainable farmers, as many sustainable farming practices rely on natural pest control to keep harmful insects, such as aphids, away from their crops. Recent transportation has been shifting away from diesel engines to electric motors as a means of transportation, meaning that air pollution levels will change. Conducting research on how different changing pollution levels will affect the populations of pest predators, and therefore we will be able to ensure future food security. This research is crucial to understanding the relationship between pollution, pests, and their predators.
Overall, I think this research is really interesting and it’s something I wouldn’t have considered to be an effect of pollution. The research from this study will be important in the future years as the amount of diesel exhaust in the air changes. Now that car owners are transitioning from diesel to electric, it will be interesting to watch how the population changes as diesel pollution drops. We may see the wasp population grow as prey becomes easier to hunt, following with the aphid population decreasing. In result, the wasp population will likely drop again soon after as the increased population uses up their food supply; aphids will populate once more. We can expect farmers to have a range of crop yields during the years when populations are fluctuating, as increased aphids will destroy more crops. But once both populations reach an equilibrium, farmers should have a more balanced yield and the sustainable and natural form of pest control will be much improved.
This article also relates to environmental science because decreased effectiveness of natural pest control methods could lead to farmers reverting to industrial methods, which are much more harmful to local ecosystems. Do you believe that this gradual transition from diesel to electric cars will be enough to maintain the effectiveness of parasitic wasps as natural pest controls, or should legislation also be put in place to further reduce exhaust levels?
Thanks for reading! I think that the gradual shift to electric cars should be enough in theory (or even gasoline cars), as the issue was the diesel exhaust. If the shift is not fast enough, there are other methods of pesticides that farmers could use instead of relying on the wasps.
This was really interesting to read, I never thought pollution could have that much of an impact on pest management. Do you think that some other thing could sprout up and control pests with parasitic wasp populations going down?
Thanks for reading! There are many different methods of pest control, so controlling pests is not the main issue, the issue is finding a way that is sustainable. Sustainable farmers take advantage of natural predation to control the pests. So to answer your question, there are other ways to control pests without wasps, but not all of them are as natural or sustainable.