Julie Sørlie Paus-Knudsen

• Paus-Knudsen, Julie Sørlie; Sveinsson, Henrik Andersen; Grung, Merete; Borgå, Katrine & Nielsen, Anders (2023). The Neonicotinoid Imidacloprid Impairs Learning, Locomotor Activity Levels, and Sucrose Solution Consumption in Bumblebees (Bombus terrestris). Environmental Toxicology and Chemistry. ISSN 0730-7268. 42(6), p. 1337–1345. doi: 10.1002/etc.5611. Full text in Research Archive Show summary

  Bumblebees carry out the complex task of foraging to provide for their colonies. They also conduct pollination, an ecosystem service of high importance to both wild plants and entomophilous crops. Insecticides can alter different aspects of bumblebee foraging behavior, including the motivation to leave the hive, finding the right flowers, handling flowers, and the ability to return to the colony. In the present study, we assessed how the neonicotinoid imidacloprid affects bumblebees' foraging behavior after exposure to four different treatment levels, including field-realistic concentrations (0 [control], 1, 10, and 100 μg/L), through sucrose solution over 9 days. We observed the behavior of several free-flying bumblebees simultaneously foraging on artificial flowers in a flight arena to register the bees' complex behavior postexposure. To conduct a detailed assessment of how insecticides affect bumblebee locomotor behavior, we used video cameras and analyzed the recordings using computer vision. We found that imidacloprid impaired learning and locomotor activity level when the bumblebees foraged on artificial flowers. We also found that imidacloprid exposure reduced sucrose solution intake and storage. By using automated analyses of video recordings of bumblebee behavior, we identified sublethal effects of imidacloprid exposure at field-realistic doses. Specifically, we observed negative impacts on consumption of sucrose solution as well as on learning and locomotor activity level. Our results highlight the need for more multimodal approaches when assessing the sublethal effects of insecticides and plant protection products in general.

• Aarønes, Malin Røyset; Paus-Knudsen, Julie Sørlie; Nielsen, Anders; Rundberget, Thomas & Borgå, Katrine (2021). Within-Body Distributions and Feeding Effects of the Neonicotinoid Insecticide Clothianidin in Bumblebees (Bombus terrestris). Environmental Toxicology and Chemistry. ISSN 0730-7268. 40(10), p. 2781–2790. doi: 10.1002/etc.5154. Full text in Research Archive Show summary

  Bumblebees can be exposed to neonicotinoid pesticides through nectar and pollen collected from treated crops, which can cause lethal and sublethal effects in these nontarget pollinators. However, the body distribution of the compound after exposure to neonicotinoids in bumblebees is not well studied. Bumblebee colonies (Bombus terrestris, n = 20) were exposed to field-realistic concentrations of clothianidin through artificial nectar (3.6–13 µg/L) for 9 d. Comparison of the nominal with the measured exposure in nectar indicated good compliance, confirming the applicability of the method. When quantified, clothianidin showed a concentration-dependent occurrence in the head and body of workers (head: <0.2–2.17 µg/kg; body: <0.2–3.17 µg/kg), and in the body of queens (<0.2–2.49 µg/kg), although concentrations were below those measured in the nectar (bioaccumulation factor = 0.2). Exposure to clothianidin did not affect mortality nor brood production, nor did it have a statistically significant effect on nectar consumption and size of food storage. However, visual inspection suggests higher nectar consumption of nectar with low clothianidin content compared with nectar with no or high clothianidin content. Our results show that dietary clothianidin is taken up in bumblebees, but does not bioaccumulate to elevated levels compared with exposure. Still, clothianidin may elicit responses that affect feeding behavior of the pollinator B. terrestris, although our endpoints were not significantly affected.

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• Paus-Knudsen, Julie Sørlie (2020). Natur i endring. [TV]. NRK. Show summary

  Er den norske naturen slik vi kjenner den i ferd med å forsvinne? Hva skjer med insektene, fisken, skogen og fjellnaturen når klimaet endrer seg? Julie Sørlie Paus-Knudsen forsker på humler og vil ut i naturlandskapet for å finne ut hvorfor insektene forsvinenr. Det hun finner er et landskap som knapt er til å kjenne igjen fra den gang det var beite og slåttemarker overalt. Norsk naturserie fra 2020.

• Bøckman, Petter; Kvellestad, Anders & Paus-Knudsen, Julie Sørlie (2020). Abels tårn. [Radio]. NRK P2.
• Paus-Knudsen, Julie Sørlie (2019). Hvordan går det med humlene?
• Aarønes, Malin Røyset; Nielsen, Anders; Paus-Knudsen, Julie Sørlie; van Bavel, Bert & Borgå, Katrine (2019). Accumulation of Clothianidin, a neonicotinoid pesticide, in bumblebees (Bombus terrestris).
• Paus-Knudsen, Julie Sørlie; Sveinsson, Henrik Andersen; Aarønes, Malin Røyset; Borgå, Katrine & Nielsen, Anders (2018). Interacting effects of neonicotinoids and temperature on bumblebee (Bombus terrestris) behaviour.
• Aarønes, Malin Røyset; Nielsen, Anders; Paus-Knudsen, Julie Sørlie; van Bavel, Bert & Borgå, Katrine (2018). Accumulation of Clothianidin, a neonicotinoid pesticide, in bumblebees (Bombus terrestris).
• Paus-Knudsen, Julie Sørlie; Nielsen, Anders; Grung, Merete & Borgå, Katrine (2018). Sub-lethal effects of imidacloprid, a neonicotinoid pesticide, on bumblebees.
• Paus-Knudsen, Julie Sørli (2016). Sublethal effects of imidacloprid, a neonicotinoid pesticide, on bumblebees.

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