Aphids manipulate their food

Last updated: 30 Aug, 2018


Aphids – who hasn’t been bothered by these little insects at one time or another? Why do they reproduce on plants so successfully? These are among the questions that Professor Dr Caroline Müller and her research team are addressing. They have found out that aphids are able to influence the quality of their food, and that this may enable them to construct a niche on their own host plants.

 

There are hundreds of different  aphid species. They all feed on plant sap, known as phloem sap. The nutritional value of the phloem sap is determined by the sugar concentration and the concentration and composition of amino acids. Previously we didn't know how the quality of plant sap changes in different plant parts after aphid infestation, how this change in quality influences the development of aphids, and how, in turn, the aphids can change the composition of the plant sap.

 


Prof. Caroline Müller and Ruth Jakobs. Photo: Bielefeld University.

 

Müller and her team are the first to confirm that aphid infestation actually does change the composition of the plant sap, depending on which aphid species is infesting which specific part of the plant. For example, infestation of the stem close to the bud with a certain aphid species changes the composition of sugar and organic acids in the sap. In contrast, infestation of the old leaves with another aphid species increases the concentration of amino acids. And a further phenomenon was also identified: ‘We were able to observe that the aphid species that developed best on the stem close to the bud and the other species that proliferated best on the old leaves each specifically increased the quality of the plant sap of the corresponding plant part,’ says Ruth Jakobs.

 


Aphid infestation of the stem close to the bud of a tansy (Tanacetum vulgare) plant. Photo: Bielefeld University / Jana Stallmann.

 

Hence, aphids construct their own niche in such a way that they are able to profit from it. ‘We can assume that aphids behave in a similar way to, for example, beavers that settle in the dams they have constructed themselves,’ says Müller.

 

Read the paper: Jakobs, R. , Schweiger, R. and Müller, C. (2018) Aphid infestation leads to plant part‐specific changes in phloem sap chemistry, which may indicate niche construction. New Phytologist. doi: 10.1111/nph.15335

 

Read the original press release.