Tr.i.fl.e - Tracking insects on flowers with e-DNA

Environmental DNA (eDNA) for a more specific, non-invasive measurement of biodiversity

DNA metabarcoding is a high-resolution molecular method for recording biodiversity. For insect sampling, mass trapping methods such as Malaise traps are often used, which are often non-specific and context-dependent, limiting detailed analysis of insect population dynamics. Environmental DNA (eDNA) is a more specific, non-invasive alternative that captures free DNA molecules in soil, water or air to measure biodiversity. Plant parts such as leaves, inflorescences or individual flowers are also increasingly being used to extract insect DNA. Pollination spectra, for example, can be analysed without direct observation of the pollination event. However, crucial questions remain unanswered: How do the taxonomic affiliation, size and behaviour of the insects as well as frequency and duration of stay on the flowers affect DNA delivery, sequence counts after sequencing and thus detection success?

New possibilities in analysing pollinator networks with far-reaching applications in insect protection

In TRIFLE, the general applicability of non-invasive eDNA metabarcoding of plant material for recording insect diversity, pollinator populations and insect-plant interactions is being investigated. Insect visits to flowers and inflorescences are documented in the field using a camera. The flowers/inflorescences are then processed using eDNA metabarcoding. The detection rate of the insect species in the molecular data set and the assigned sequence numbers are analysed with the characteristics and behaviour of the insects documented via video. To obtain additional data for the overall diversity present in the test habitat, additional DNA metabarcoding data will be generated from insect traps in the surrounding area. Being able to analyse insect-plant interactions independently of observations over a longer period of time opens up new possibilities in the analysis of pollinator networks with far-reaching applications in insect conservation, ecosystem services, food security and in the evaluation of scientific collections.