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Biology subjects

Tissier, M. L.

Publications and source records attributed to Tissier, M. L..

2 recordsLinked to original sources

Risk assessments underestimate threat of pesticides to wild bees

Ecological risk assessments (ERA) are crucial when developing national strategies to manage adverse effects from pesticide exposure to natural populations. Yet, estimating risk with surrogate species in controlled laboratory studies jeopardizes the ERA process because natural populations exhibit intraspecific variation within and across species. Here, we investigate the extent to which the ERA process misestimates risk from pesticides on different species by conducting a meta-analysis of all records in the ECOTOX Knowledgebase for honey bees and wild bees exposed to neonicotinoids. We found the knowledgebase is largely populated by acute lethality data on the Western honey bee and exhibits within and across species variation in LD50 up to six orders of magnitude from neonicotinoid exposure. We challenge the reliability of surrogate species as predictors when extrapolating pesticide toxicity data to wild pollinators and recommend solutions to address the (a)biotic interactions occurring in nature that make such extrapolations unreliable in the ERA process. SynopsisEcological risk assessments misestimate pesticide threats to pollinators sixfold by overextending acute lethality data on surrogate species to natural populations.

ecology↗

Supplementation in vitamin B3 counteracts the negative effects of tryptophan deficiencies in bumble bees

Increasing evidence highlights the importance of diet content in 9 essential amino acids for bee physiological and behavioral performance. However, the tenth essential amino acid, tryptophan, has been overlooked as its experimental measurement requires a specific hydrolysis. Tryptophan is the precursor of serotonin and vitamin B3, which together modulate cognitive and metabolic functions in most animals. Here, we investigated how tryptophan deficiencies influence the longevity and behavior of bumble bees. Tryptophan-deficient diets led to a moderate increase in food intake, aggressiveness and mortality compared to the control diet. Vitamin B3 supplementation in tryptophan-deficient diets tended to buffer these effects on food intake and survival, and significantly reduced workers aggressiveness. Considering that the pollens of major crops and common plants, such as corn and dandelion, are deficient in tryptophan, these effects could have a strong impact on bee populations and their pollination service.

physiology↗