Consequences of exposure to sublethal imidacloprid doses in a widely distributed collembolan

Collembolans are important contributors to the decomposition of plant litter into humus and mineralized chemical components available for absorption by plant roots. They occur abundantly in most habitat types, including forests and agricultural fields. They are, therefore, prone to be exposed to anthropogenic chemicals and toxins, including pesticides. However, only few ecotoxicological studies focus on collembola species that dominate their natural habitats.

Bildet kan inneholde: organisme, jord, flatworm.

Figure: Folsomia quadrioculata adults (a and b) and juveniles (c) feeding in culture

Imidacloprid, a broad-spectrum neonicotinoid insecticide, is known to persist in soil for more than 100 days. However, our knowledge on the consequences of chronic exposure to sublethal doses of this neurotoxic pesticide for populations of soil- and litter-dwelling collembolans is limited.

Focusing on Folsomia quadrioculata, which dominates many habitat types in the northern hemisphere, our group aims to understand the combined effect of imidacloprid exposure and temperature stress on life history traits and population dynamics. We have studied thermal adaptation in this species extensively and identified the sublethal dose range of imidacloprid using lab- and field-based methods. However, predicting its responses under natural field conditions based on the findings from the lab is challenging, and this issue will be addressed in this master project.

In the proposed project, F. quadrioculata will be released in microcosms consisting of field-collected, defaunated soil cores (microcosms) spiked with sublethal doses of imidacloprid. The experimental replicates would be sampled at regular intervals for determining the effects of imidacloprid on growth, recruitment, and survival of the focal species. The effects of doses will be compared with positive and negative controls.The findings will be compared with those of ongoing lab and field studies. In addition, it might be possible for the master student to contribute to population modeling efforts for predicting the consequences in the field.

If you are interested in a master topic that combines ecological and ecotoxicological questions within the scheme of the MULTICLIM project (https://www.mn.uio.no/ibv/english/research/sections/aqua/research-projects/144612/) and interested in working hands-on on a lab based experiment with soil organisms, please do not hesitate to contact us!

Supervisor: Katrine Borgå (katrine.borga@ibv.uio.no)

Co-supervisor: Sagnik Sengupta (sagnik.sengupta@ibv.uio.no)

 

Publisert 15. aug. 2019 07:59 - Sist endret 15. aug. 2019 07:59

Omfang (studiepoeng)

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