Short-term lab assessments and microcolonies are insufficient for the risk assessment of insecticides for bees

No evidence of effects or interaction between the widely used herbicide, glyphosate, and a common parasite in bumble bees

“…Indeed, it is possible that both microcolony experiments were power limited, with ∼10 microcolonies per treatment (a total of 38 and 36 microcolonies in each experiment). This is less than other microcolony experiments like Oystaeyen et al (2020) which used 20 per treatment, and ( Siviter et al, 2020 ) which used 30 per treatment. The power limitation hypothesis is supported by the lack of a significant effect of C. bombi on reproductive success in both experiments, which contrasts with a range of published literature ( Yourth, Brown & Schmid-Hempel, 2008 ; Shykoff & Schmid-Hempel, 1991 ; Brown, Schmid-Hempel & Schmid-Hempel, 2003 ).…”

“…Drone production by unmated workers in a microcolony set up is designed to function as a proxy of this, and itself does not directly represent a field realistic measure of whole colony sexual production. There is even some evidence that microcolonies can give contradictory results to queenright laboratory or full field experiments ( Oystaeyen et al, 2020 ). As such our results should be interpreted with caution, and are not a field realistic measure of reproductive success.…”

Peer Review #1 of "No evidence of effects or interaction between the widely used herbicide, glyphosate, and a common parasite in bumble bees (v0.1)"

“…Indeed, it is possible that both microcolony experiments were power limited, with ~10 microcolonies per treatment (a total of 38 and 36 microcolonies in each experiment). This is less than other microcolony experiments like Oystaeyen et al (2020) which used 20 per treatment, and Siviter et al (2019) which used 30 per treatment. The power limitation hypothesis is supported by the lack of a significant effect of C. bombi on reproductive success in both experiments, which contrasts with a range of published literature (Yourth, Brown and Schmid-Hempel 2008, Shykoff and Schmid-Hempel, 1991, Brown, Schmid-Hempel, and Schmid-Hempel 2003.…”

Thiamethoxam as an inadvertent anti-aphrodisiac in male bees

“…Given our laboratory findings can be extrapolated to the field and hold true across various insect taxa, which appears likely due to the non-specific mode of action and widespread neonicotinoid pollution globally [ 25 , 96 ], this may help understand recent insect population declines; especially for those species where unfertilized eggs do not hatch [ 97 , 98 ]. Therefore, to fully understand the potential threat of xenobiotic substances on ecosystems, we urge risk assessments to determine the ecological effects on fitness of individuals, colonies and entire populations [ 99 , 100 ].…”