Dr Dirk Sanders of the University of Exeter demonstrated that orb web spiders – like the common garden variety – choose to eat pollen even when insects are available.
Orb weaver spiders -- like the common garden variety -- choose to eat pollen even when insects are available.
Credit: Dirk Sanders
Spider webs snare insect prey, but can also trap aerial plankton like pollen and fungal spores.
Dr Sanders, alongside Mr Benjamin Eggs from the University of Bern, conducted feeding experiments and a stable isotope analysis on juvenile spiders to see whether they incorporate plant resources into their diet.
They discovered that 25 per cent of the spiders' food intake was made up of pollen, with the remaining 75 per cent consisting of flying insects.
The spiders that ate both pollen and flies gained optimal nourishment, with all essential nutrients delivered by the combination.
Dr Sanders, of the Centre for Ecology and Conservation at the University of Exeter's Penryn Campus, said: "Most people and researchers think of spiders as pure carnivores, but in this family of orb web spiders that is not the case. We have demonstrated that the spiders feed on pollen caught in their webs, even if they have additional food, and that it forms an important part of their nourishment.
"The proportion of pollen in the spiders' diet in the wild was high, so we need to classify them as omnivores rather than carnivores."
Orb web spiders regularly take down and eat their webs to recycle the silk proteins, and it had been suggested they may 'accidentally' consume the pollen during this process.
But the study found this to be impossible due to the size of the grains ingested, indicating that they were actively consumed by the spider coating them in a digestive enzyme before sucking up the nutrients.
The research paper, Herbivory in Spiders: The Importance of Pollen for Orb-Weavers, is published in the journal PLOS One.
Eleanor Gaskarth | EurekAlert!
Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)
CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
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...
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...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
19.01.2017 | Earth Sciences
19.01.2017 | Life Sciences
19.01.2017 | Physics and Astronomy