Despite more than 250 years of taxonomic research, many insect species remain to be discovered or described, not only in the tropics but also in Sweden. The majority of these species are parasitic wasps, flies or mosquitoes. They are usually small and inconspicuous insects that are either decomposers or parasitoids, a kind of specialized predators. Many of the undescribed species are common and widespread, and they probably play significant roles in our ecosystems.
In the Swedish Malaise Trap Project, we survey the Swedish insect fauna using tent-like Malaise traps, which are very effective in collecting specimens of the poorly known groups of parasitic wasps and dipterans (flies and mosquitoes). Among other things, we use the results from this inventory to estimate the size and composition of the Swedish insect fauna. Our current estimates indicate that thousands of insect species remain to be discovered in Sweden, many of them presumably still unknown to science.
We also study phylogenetic relationships and describe new species of poorly known insect groups, including scuttle flies (Phoridae) and different groups of parasitic wasps (Braconidae: Euphorinae and Opiinae). Often, a majority of the studied material comes from the Swedish Malaise Trap Project. We use a combination of genetic approaches and simplified descriptions to speed up the taxonomic work on these groups.
We also develop new gene-based methods for analyzing the species composition of bulk insect samples from Malaise traps and other types of sampling methods. The goal is to be able to identify thousands of specimens at a time using new sequencing machines that can read millions of DNA strings simultaneously. This will enable us to dramatically speed up insect diversity inventories, opening up new opportunities for systematic and ecological research as well as for environmental monitoring.
Biosystematics, informatics and genetics of the big four insect orders (http://big4-project.eu/)
Svenska Malaisefälleprojektet vid Station Linné (http://www.stationlinne.se/en/research/the-swedish-malaise-trap-project-smtp/)
Stigenberg J, Ronquist F. 2011. Revision of the Western Palearctic Meteorini (Hymenoptera, Braconidae), with a molecular characterization of hidden Fennoscandian species diversity. Zootaxa 3084: 1-95.
Karlsson D, Ronquist F. 2012. Skeletal morphology of Opius dissitus and Biosteres carbonarius (Hymenoptera: Opiinae), with a discussion of terminology. PLoS ONE 32:e32573.
Stigenberg J, Boring CA, Ronquist F. 2015. Phylogeny of the parasitic wasp subfamily Euphorinae and evolution of its host preferences. Systematic Entomology 40: 570–591.
Häggqvist S, Ulefors SO, Ronquist F. 2015. A new species group in Megaselia, the lucifrons group, with description of a new species (Diptera, Phoridae). ZooKeys 512: 89–108.
Häggqvist S. 2016. Charting biodiversity: Scuttle flies and other poorly known insects in Sweden (PhD dissertation). Stockholm University. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-133436.