Jan Erik Sedlmeier - Doktorand

In my doctoral thesis, I am investigating the effects of pesticide pollution in agroecosystems on non-target insects.

Pesticides: Effects on terrestrial non-target insect communities

The use of synthetic chemical pesticides as a result of agricultural intensification is suspected of being one of the driving forces behind insect mortality. Research in this area is focussed primarily on the effects on important beneficial insects such as honey bees and aquatic organisms. However, far too little is known about the effects of pesticide exposure on terrestrial insect communities. Moreover, many of the available studies are based on single exposure scenarios, often in controlled laboratory environments, and on single species tested. In one of my projects, I am therefore investigating the effects of insecticide exposure on a species community of typical meadow insects, the plant bugs (Heteroptera: Miridae). In a combination of field, greenhouse and laboratory experiments, I am simulating different exposure scenarios and investigating species- and sex-specific differences in sensitivity to insecticides. 

We know that not only insecticides can have a damaging effect on insects. In another project, I am investigating the effects of fungicides on non-target insects, using practical scenarios and environmental measurements as a guide.

Synergistic effects of pesticide combinations: A potential threat for non-target organisms

Plant protection products are tested and authorised individually for their potential environmental hazard, but in nature, non-target organisms come into contact with several active substances at the same time. Possible interactions can lead to so-called synergy effects, i.e. an increased effect of the combined active substances compared to the additive effect of the individual substances. This is alarming given the large number of authorised active ingredients and the resulting theoretical combinations. However, this field of ecotoxicology has hardly been studied compared to single substance effects. In a third project, I am therefore investigating how the combination of active substances from different classes (insecticide, fungicide, herbicide) affects model organisms such as the silk plant bug Oncopeltus fasciatus (Heteroptera: Lygaeidae).

Expertise

• Field, greenhouse and laboratory trials on the effect of pesticides on non-target insects
• Dose-response bioassays with pesticides
• Broad taxonomic knowledge of insects
• Statistical analysis (R) of experiments using linear and generalised (mixed) linear models