Scientists warn of insect pest outbreaks and reduced wheat yields

October 23, 2018, Newcastle University
Credit: CC0 Public Domain

Climate-warming affects farmlands by increasing pests but not their natural predators, resulting in reduced crop yields, new research has revealed.

The study, published today in the journal, Molecular Ecology, provides the first experimental evidence of how the interactions between agricultural plants, greenflies and tiny parasitoid wasps are affected in a world where temperatures are increased by 1.4°C.

Scientists at Newcastle University and the University of Hull have also shown that a rise in temperature drives changes in the crop, altering the growing patterns of the wheat that produced fewer, lighter seeds.

New approach

Dr. Darren Evans, Reader in Ecology and Conservation at Newcastle University, and the leader of the study, said the research findings provide a further understanding into the impact of climate-change.

He said: "There have been a number of recent high-profile studies that have modelled the long-term effects of climate-change on crops using computers, but there are surprisingly few studies that have tested this using field experiments on farms.

"Most models examine the impacts on , but often fail to take into account that crops are embedded in a wider network of interactions with organisms that can also directly and indirectly impact upon the crop as a result of climate-change.

"We used a network approach to better understand the impact on the farmland food-web."

By simulating a warmer, wetter environment, the team suspended infrared heaters above a wheat crop in Yorkshire, whilst also managing rainwater and found significant changes to the food-web.

In order to study the network of species interactions, the team developed a DNA-based tool to rapidly identify greenflies collected in the field, enabling them to see whether they had been parasitsed as well as the identity of the natural predator based on the DNA of their eggs injected into the insects.

Dr. Evans said: "In the first year of the experiment, we found that climate-warming affected the structure and complexity of the species-interaction networks.

"Some species where more affected than others but we observed four times as many greenflies in the warmed plots compared to the controls.

"Although it must be stressed that our experimental plots were not managed in a way similar to conventional wheat , and the study was based on a single growing season, our results support growing evidence that climate-change will increase pests and pathogens and reduce crop yields in some temperate agro-ecosystems."

Further research

The scientists found no effect of adding extra rainwater, despite the year of study being unseasonable dry, suggesting that increased irrigation by farmers might not mitigate the effects climate-warming.

They are now examining subsequent year's data to understand variation across growing seasons and plan to include a wider range of above and below-ground organisms in the networks.

Dr. Evans added: "New approaches in ecology, combined with DNA-based tools, could help us to better understand and mitigate adverse effects of climate-warming through targeted management of non-crop plants, farm habitats and .

"Further work must include other important factors, such as increases in carbon dioxide, if we are going to make experiments and models more predictive. Ideally projects such as these should be replicated beyond a single experimental farm to incorporate wider geographical areas and a diversity of agro-ecosystems."

Explore further: Climate changes require better adaptation to drought

More information: Stephane A.P. Derocles et al. Climate-warming alters the structure of farmland tri-trophic ecological networks and reduces crop yield, Molecular Ecology (2018). DOI: 10.1111/mec.14903

Related Stories

Climate changes require better adaptation to drought

October 17, 2018

Europe's future climate will be characterised by more frequent heat waves and more widespread drought. Heat and drought will both challenge crop production, but drought in particular will be a problem—especially for spring ...

Global warming: More insects, eating more crops

August 30, 2018

Crop losses for critical food grains will increase substantially as the climate warms, as rising temperatures increase the metabolic rate and population growth of insect pests, according to new research.

Soil holds the secret to mitigating climate change

September 17, 2018

Food production doesn't have to be a victim of climate change. New research from Michigan State University suggests that crop yields and the global food supply chain can be preserved by harnessing the critical, and often ...

Whether wheat weathers heat waves

June 20, 2018

A heat wave sweeps through a city and people swelter, running indoors to find air conditioning. But crops out in a field aren't so lucky. For them, there is no escape.

Climate change will cut crop yields: study

August 15, 2017

Climate change will have a negative effect on key crops such as wheat, rice, and maize, according to a major scientific report out Tuesday that reviewed 70 prior studies on global warming and agriculture.

Recommended for you

Matter waves and quantum splinters

March 25, 2019

Physicists in the United States, Austria and Brazil have shown that shaking ultracold Bose-Einstein condensates (BECs) can cause them to either divide into uniform segments or shatter into unpredictable splinters, depending ...

How tree diversity regulates invading forest pests

March 25, 2019

A national-scale study of U.S. forests found strong relationships between the diversity of native tree species and the number of nonnative pests that pose economic and ecological threats to the nation's forests.

Study suggests trees are crucial to the future of our cities

March 25, 2019

The shade of a single tree can provide welcome relief from the hot summer sun. But when that single tree is part of a small forest, it creates a profound cooling effect. According to a study published today in the Proceedings ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.