SLU news

Can natural enemies provide biological control of aphids in a changing climate?

Published: 31 March 2020
A young lady sits cross-legged on a lawn, photo.

Asmita Baral has just started doing her master thesis work at SLU. She wants to find out if a diversity of natural enemies can provide stable biological control of aphids when the climate changes. We took the opportunity to ask her some questions!

The need to reduce chemical pesticides in agriculture has opened up for other methods, such as the use various biological control agents. One important area is to explore and conserve already present biological control agents in the ecosystem. These agents, called natural enemies, provide these ecosystem services naturally. The name of Asmita’s projects is “Can a diversity of natural enemies provide stable aphid control in the future?” and she will be working with Ben Feit and Mattias Jonsson. The master thesis is done within the SLU Centre for Biological Control.

From Kathmandu to Göttingen to Valencia to Uppsala

Asmita is originally from Kathmandu in Nepal and are currently studying in an Erasmus+ Master’s Program on plant health in sustainable cropping systems.

– In this program, I studied my first year of my Master at the University of Göttingen, Germany. Right now, I have been doing my second year at Universitat Politechnica de Valencia, Spain. The final part of my master will be the thesis work that I am now carrying out at SLU.

Doing a masters in these times of the covid-19 pandemic, how does that work out?

– I managed to travel to Sweden before the pandemic. The original plan was to start working in this project at the beginning of March. However, due to the current covid-19 pandemic, the experiments will instead be starting later on in the summer. I will be in Sweden until end of the August. Hopefully, I will be able to complete the work in time.

How does climate change affect interactions of natural enemies?

It is a growing concern to understand how changing environmental conditions are affecting the interactions among natural enemies and the ecosystem services provided by them.

– My project is about the effects of climatic variation on the potential of individual carabid pecies to control aphids, says Asmita.

Asmita will be conducting experiments with different carabid beetles and the bird cherry oat aphid (Rhopalosiphum padi) under various climatic conditions in the climatic chamber.

– It is an interesting project for me. I really am a biological control enthusiast and love to work on topics related to aspects of biological control. During my internship at the University of Göttingen in Germany, I worked on the biocontrol potential of Metarihizium sp. isolates on two of the aphid species in oil seed rape, which had promising results, says Asmita.

What are your hopes for the work here at SLU?

– I hope we will find out more about the sustainability of these ecosystem services provided by diverse natural enemies for controlling major pests in agriculture in the longrun. This is something that researchers in food production system and ecologists around the world are looking into right now. However, this is a small study in this context, but I hope I will get interesting results. I hope that I will get the opportunity to work on related projects in the future as well, says Asmita.

Do you think something will be extra hard and/or interesting?

– It would be interesting to observe the interactions among the predators in response to the climate change. There may be instances of interference interactions, when predators spend time defending their hunting locations, and through intraguild predation, in which one species prey upon other competitor species that reduces the abundance or causes the loss of a predator species. This is something I am very interested to observe in this project, says Asmita.

When you are not studying, what do you like to do?

– I love to read novels, travel and take photographs in my free time!

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