At the thought of aphids, people often just want to control them. In addition to the pests on crop and ornamental plants or the producers of forest honey, there are many other species of aphid, but we know little about them. 350 species have been described so far in Switzerland. Most of them were discovered by chance, such as the Myzodium modestum aphid, which lives in and feeds on moss. This species occurs in Switzerland’s neighboring countries, as well as in Scandinavia, Russia, Greenland and North America, but until now no specimen has been found in Switzerland – because no one looked! WSL researchers came across it by chance in the Swiss National Park in summer 2013 when they were checking food webs in pastures.
What made the find so special is that it consisted of two winged males and a female. Such sexual forms have never been identified in aphids living exclusively on moss before. Scientists assumed that these aphid species were propagated through parthenogenesis, a form of asexual reproduction in which the young develop from unfertilized eggs. Finding these sexual forms in the Swiss National Park has now disproved this assumption – a small step for science, but great satisfaction for the discoverer. (Lisa Bose, Diagonal 1/17)