3D X-ray view of an amber fossil

Research team unravels secrets of 50-million-year-old parasite larvae

With the intense X-ray light from DESY’s particle accelerator PETRA III, researchers have investigated an unusual find: a 50-million-year-old insect larva from the era of the Palaeogene. The results offer a unique insight into the development of the extinct insect, as the team reports in the journal Arthropod Systematics & Phylogeny.
When the biologist Hans Pohl from the Friedrich Schiller University in Jena tracked down an insect fossil trapped in amber on eBay, the joy of discovery was great: it was a special specimen, a 50-million-year-old larva of an extinct twisted-wing insect from the order of Strepsiptera. But in order to be able to investigate it in detail, he needed the help of materials researchers from the Helmholtz Centre in Geesthacht, which operates a beamline at DESY’s X-ray source PETRA III.
Strepsiptera are parasites that infest other insects, such as bees and wasps, but also silverfish. “In most of the approximately 600 known species, the females remain in their host throughout their lives,” says Pohl. “Only the males leave it for the wedding flight, but then live only a few hours.” But there are exceptions: In species that infest silverfish, the wingless females also leave their host.

>Read more on the PETRA III at DESY website

Image: The fossil in amber. Its age lies between 42 to 54 million years. This fossil was scientifically examined at the Institute for Zoology and Evolutionary Research at the University of Jena.
Credit: FSU, Hans Pohl 

Photonic structure of white beetle wing scales: optimized by evolution

They have developed a complicated three-dimensional photonic structure on their wing scales in order to efficiently reflect white light.

At the same time, this structure is very porous and is confined within a thin layer of about 10  µm, about one fifth of the thickness of ordinary white paper, which makes it very light and therefore advantageous to fly.

Researchers of the University of Fribourg and their collaborators wanted to understand how this fascinating structure is optimized, for which they needed a faithful 3D image. However, conventional microscopy techniques providing enough spatial resolution such as electron microscopy required the sample to be cut for imaging consecutive slices, causing damage of the structure during the process.

>Read More on the PSI website

Image: Cyphochilus white beetle source: PSI