Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Eat up all of your Brussels sprouts - unless you're an aphid

08.02.2008
Aphids that eat Brussels sprouts are smaller than normal and live in undersized populations, which has a negative knock-on effect up the food chain according to new research published today (8 February) in Science.

The study shows for the first time that the nutritional quality of plant food sources for herbivores has a far-reaching impact on an ecosystem as a whole, potentially impeding important functions that the ecosystem performs, such as the natural predation and control of agricultural pests.

The scientists compared aphids living on sprouts to aphids living on wild cabbages in a field experiment which took place on a farm in theNetherlands. They could see that the sprouts were of a lower nutritional value for aphids than the cabbages, because the aphids feeding on them were smaller in size, and the number of aphids living on them was fewer.

They then traced the effects up through the food chain to discover that the implications of poor nutritional quality in plants spread throughout the extended network of feeding relationships in an ecosystem known as a food web. This means that the sprouts affect not only the herbivore aphids that eat them, but also the primary parasitoid wasp predators that mummify and eat the aphids, and the secondary parasitoid wasps that in turn eat the primary parasitoid wasps.

The scientific team made this discovery by analysing the food webs associated with both types of plants. They found that food webs based on sprout-eating aphids are less complex and involve a less diverse network of predators than those food webs based on higher quality plants like wild cabbage.

This is because larger, cabbage-eating aphids produce larger primary parasitoid predators, which in turn attract more of the opportunistic generalist feeders among the secondary parasitoids, leading to a greater diversity of species and complexity in the ecosystem. This shows that plant quality indirectly influences the foraging decisions taken by individuals higher up the food chain which ultimately determines the structure of the food web.

One of the paper's authors, Dr Frank Van Veen from Imperial College London's NERC Centre for Population Biology, explains why this is important:

"The diversity and complexity of food webs have long been seen as good indicators of how well an ecosystem is functioning, and how stable it is, but until now we had very little idea of the processes that determine diversity and complexity. Our study has shown that changing just one element, in this case plant quality, leads to a cascade of effects that impact on predators across the food web.

"If we are to predict how environmental change is going to affect ecosystems and the functions they perform, an important part of the puzzle is to understand the mechanisms by which an effect on one species propagates through the complex network of interacting species that make up an ecosystem."

Dr Van Veen adds that their research has no implications for human sprout consumption: "Our aphid study certainly does not mean sprouts aren't good for humans to eat - our nutritional requirements differ enormously from those of insects."

The research was jointly led by scientists at Wageningen University in the Netherlands and Imperial College London, and was funded by the Netherlands Organisation for Scientific Research (NWO) and the UK Natural Environment Research Council.

Danielle Reeves | alfa
Further information:
http://www.imperial.ac.uk

More articles from Agricultural and Forestry Science:

nachricht Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

nachricht New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Satellite-based Laser Measurement Technology against Climate Change

17.01.2017 | Machine Engineering

Studying fundamental particles in materials

17.01.2017 | Physics and Astronomy

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>