Synthetic fertilizers alter floral biophysical cues and bumblebee foraging behavior

Abstract

The use of agrochemicals is increasingly recognized as interfering with pollination services due to its detrimental effects on pollinators. Compared to the relatively well-studied chemical toxicity of agrochemicals, little is known on how they influence various biophysical floral cues that are used by pollinating insects to identify floral rewards. Here, we show that widely used horticultural and agricultural synthetic fertilizers affect bumblebee foraging behavior by altering a complex set of interlinked biophysical properties of the flower. We provide empirical and model-based evidence that synthetic fertilizers recurrently alter the magnitude and dynamics of floral electrical cues, and that similar responses can be observed with the neonicotinoid pesticide imidacloprid. We show that biophysical responses interact in modifying floral electric fields and that such changes reduce bumblebee foraging, reflecting a perturbation in the sensory events experienced by bees during flower visitation. This unveils a previously unappreciated anthropogenic interference elicited by agrochemicals within the electric landscape that is likely relevant for a wide range of chemicals and organisms that rely on naturally occurring electric fields.

An analysis of time-varying dynamics in electrically sensitive arthropod hairs to understand real-world electrical sensing

“…Furthermore, there is a growing body of experimental evidence demonstrating the behavioural implications of electroreception and the detection of weak electrical fields. This evidence includes work on spiders [5], bumblebees [3,42], honeybees [4,43], ticks [44] and hoverflies [6].…”

Fertilizer and herbicide alter nectar and pollen quality with consequences for pollinator floral choices

“…Decreased floral resource quality, aside from quantity, could be one mechanism behind observed changes in pollinator health over landscape scales ( Kaluza et al, 2018 ; Parreño et al, 2021 ). In addition, exposure to agrochemicals could alter other attributes of the interaction between plants and flower-visiting insects, including electrical signals ( Hunting et al, 2022 ), susceptibility to parasites ( Baron, Raine & Brown, 2014 ), and decreased foraging efficiency ( Boff et al, 2022 ).…”

Biodiversity and Challenges of Honey Bee Population in Pakistan

“…When fertilizers are applied to crops or plants, their metabolites and metal pollutants can contaminate the nectar and pollen of these plants, diminishing their nutritional content and potentially posing toxicity to nectar-feeding organisms [94,95]. Even though flower morphology and smell changed by fertilizers do not seem to affect the foraging behavior of honey bees, these chemicals can modify the complex set of interlinked biophysical properties of the flower thus affecting the behavior of bees [96]. All these factors cumulatively result in reduced bee health and reproductive success, and can also lead to population declines.…”