Comparing bee species responses to chemical mixtures: Common response patterns?

Abstract

Pollinators in agricultural landscapes can be exposed to mixtures of pesticides and environmental pollutants. Existing mixture toxicity modelling approaches, such as the models of concentration addition and independent action and the mechanistic DEBtox framework have been previously shown as valuable tools for understanding and ultimately predicting joint toxicity. Here we apply these mixture models to investigate the potential to interpret the effects of semi-chronic binary mixture exposure for three bee species: Apis mellifera, Bombus terrestris and Osmia bicornis within potentiation and mixture toxicity experiments. In the potentiation studies, the effect of the insecticide dimethoate with added propiconazole fungicide and neonicotinoid insecticide clothianidin with added tau-fluvalinate pyrethroid acaricide showed no difference in toxicity compared to the single chemical alone. Clothianidin toxicity showed a small scale, but temporally conserved increase in exposure conducted in the presence of propiconazole, particularly for B. terrestris and O. bicornis, the latter showing a near three-fold increase in clothianidin toxicity in the presence of propiconazole. In the mixture toxicity studies, the dominant response patterns were of additivity, however, binary mixtures of clothianidin and dimethoate in A. mellifera, B. terrestris and male O. bicornis there was evidence of a predominant antagonistic interaction. Given the ubiquitous nature of exposures to multiple chemicals, there is an urgent need to consider mixture effects in pollinator risk assessments. Our analyses suggest that current models, particularly those that utilise time-series data, such as DEBtox, can be used to identify additivity as the dominant response pattern and also those examples of interactions, even when small-scale, that may need to be taken into account during risk assessment.

Osmia bicornis is rarely an adequate regulatory surrogate species. Comparing its acute sensitivity towards multiple insecticides with regulatory Apis mellifera endpoints

“…We therefore agree with Heard et al (2017) that A. mellifera is a sufficient 258 proxy for wild bee species in laboratory acute mortality testing [17]. However, it is still 259 necessary to investigate less well-known issues such as effects of pesticides mixtures [32,33], prolonged pesticides exposure [17] or effects of pesticide adjuvants [34]. 261 An assessment factor of 10 proved to be protective for O. bicornis when applied honey 262 bee endpoints for nearly all tested insecticides.…”

“…However, wild bee species (i.e. bumble bees, solitary bees) may show 32 quite different responses to pesticide exposure due to differences in physiology and 33 ecology [14]. As a reaction to the information scarcity regarding the sensitivity of 34 bumble bees and solitary bees, the European Food Safety Authority (EFSA) proposed 35 the inclusion of the buff-tailed bumblebee Bombus terrestris and the red mason bee…”

The AmP project: Comparing species on the basis of dynamic energy budget parameters

“…Comparison of species is, however, not the only important application of the AmP website. Prediction of effects of global change [ 5 ], understanding the geographic distribution of species [ 6 – 8 ], the effects of (toxic) chemical compounds [ 9 – 12 ], the optimization of bio-production (e.g. aquaculture and agriculture [ 13 – 15 ]), stock management, the best re-introduction of endangered species or the control of invading species [ 16 ], are just examples of applications where detailed knowledge of energetics of species in a DEB context is very useful.…”

Effects of Field-Realistic Concentrations of Carbendazim on Survival and Physiology in Forager Honey Bees (Hymenoptera: Apidae)

“…Previous studies showed that inhibiting P450 activity can greatly increase toxicity of several pyrethroids ( Johnson et al 2006 , 2012 ) and neonicotinoid insecticides ( Iwasa et al 2004 , Manjon et al 2018 ) to honey bees. The ergosterol biosynthesis inhibitor (EBI) fungicides are known to suppress P450 activity ( Hassold et al 2009 ), and the presence of some EBI fungicides can also enhance neonicotinoids toxicity to honey bees ( Sgolastra et al 2017 , Robinson et al 2017 , Tsvetkov et al 2017 ).…”