Honey bees (Apis mellifera spp.) respond to increased aluminum exposure in their foraging choice, motility, and circadian rhythmicity

Abstract

Aluminum is increasingly globally bioavailable with acidification from industrial emissions and poor mining practices. This bioavailability increases uptake by flora, contaminating products such as fruit, pollen, and nectar. Concentrations of aluminum in fruit and pollen have been reported between 0.05 and 670mg/L in North America. This is particularly concerning for pollinators that ingest pollen and nectar. Honey bees represent a globally present species experiencing decline in Europe and North America. Region specific decline may be a result of differential toxicity of exposure between subspecies. We find that European honey bees ( Apis mellifera mellifera ) may have differential toxicity as compared to two allopatric Mediterranean subspecies ( Apis mellifera carnica and Apis mellifera caucasica ) which showed no within subspecies exposure differences. European honey bees were then used in a laboratory experiment and exposed to aluminum in their daily water supply to mimic nectar contamination at several concentrations. After approximately 3 weeks of aluminum ingestion these bees showed significantly shorter captive longevity than controls at concentrations as low as 10.4mg/L and showed a possible hormetic response in motility. We also compared European honey bees to Africanized/European hybrid bees ( Apis mellifera mellifera/scutellata hybrid) in short-term free-flight experiments. Neither the European honey bee nor the hybrid showed immediate foraging deficits in flight time, color choice, or floral manipulation after aluminum exposure. We conclude that European honey bees are at the greatest risk of aluminum related decline from chronic ingestion as compared to other subspecies and offer new methods for future use in honey bee toxicology.

Low Strength Magnetic Fields Serve as a Cue for Foraging Honey Bees but Prior Experience is More Indicative of Choice

“…The present study used a scaled‐down version from prior literature with larger flowers to control for MF gradient, and a reduction in the number of choices from 36 to 4 because of the number of observers required to conduct a full‐scale flower patch [Karahan et al, 2015]. Yellow and blue flower colors were chosen as bees typically have a strong strong preference for one or the other as opposed to a blue‐white comparison in which preferences can be manipulated [Chicas‐Mosier et al, 2017, 2019]. The white plastic board that supported the flowers was balanced on both MF generator disks.…”

“…These insects are experiencing population decline, along with other pollinators as a result of pathogens, habitat destruction, and pesticide application [Goulson et al, 2015; Hallmann et al, 2017]. Honey bees have been used as a model organism to study responses to pesticide exposure, learning, neuroadaptation, and environmental impacts and have been shown to discriminate between MFs [Walker and Bitterman, 1989a,b; Abramson et al, 2012a; Williamson and Wright, 2013; Karahan et al, 2015; Chicas‐Mosier et al, 2019]. They also are easy to rear, manage, and allow for large sample sizes with similar environmental background conditions.…”

Preliminary Evidence That Fiji Water Has Protective Effects against Aluminum Toxicity in Honey Bees (Apis mellifera)

“…Inhibition of AChE can also result in physiological effects such as spasms, hyperactivity, and erratic movement [ 15 , 16 ]. Hyperactivity can disrupt the diurnal circadian rhythms of forager bees, which may cause them to miss key foraging times for specific plants [ 17 ].…”

“…The ingestion of aqueous aluminum has been determined to affect floral foraging decisions made by honey bees [ 17 , 18 ]. Bees that were fed an aluminum solution exhibited reduced flexibility to changing floral environments [ 17 , 18 ].…”

Effects of ethanol ingestion on aversive conditioning in honey bees (Apis mellifera L.).

“…Subspecies differences have been detected in the learning ability of Africanized and European subspecies (Abramson et al, 1997) and between Apis mellifera caucasica and Apis mellifera syriaca . In addition to subspecies differences in learning ability, it is also known that honey bee subspecies also differ in their antipredator behavior (Kandemir et al, 2012) and in behavior following exposure to other bioavailable substances (Chicas-Mosier et al, 2019). Further, evidence has shown that honey bees subject to passive avoidance paradigms can exhibit behavior altered by factors outside of the experimental session.…”