The Latest in Bee Research

Bumblebees with a Neonicotinoid Addiction

Experiments designed to determine the effect of pesticides, particularly neonicotinoids, on bees have generally involved feeding individuals with syrup containing different levels of the chemicals. This study at Imperial College London looked at the foraging preferences of bumblebees in a situation that mimics natural field conditions more closely.

Over ten days, colonies of bumblebees were given access to sucrose feeders containing zero, two and eleven parts per billion of thiamethoxam. Over the period, there was an increase in visits to feeders containing the pesticide. Even when the position of each feeder was altered, the bees showed a preference for feeders containing thiamethoxam. The results indicate an increased risk of consuming neonicotinoid-treated food in the field. As well as considering the proportion of floral resources contaminated by pesticides, the attractiveness of these to bees also needs to be incorporated into calculations of the risks.


Arce, AN, et al (2018). Foraging bumblebees acquire a preference for neonicotinoid-treated food with prolonged exposure. Proceedings of the Royal Society B. doi: 10.1098/rspb.2018.0655 (

Investigate Sulfoximine’s Effects on Bumblebees

Sulfoximines are seen as potential replacements for neonicotinoids. This group of chemicals works on the same class of receptors in the insect brain but can avoid the enzymes which give the insects a level of resistance. However, concerns are increasing regarding environmental effects including potential toxic effects on bumblebees.

The first sulfoximine on the market is sulfloxaflor. Researchers at Royal Holloway, University of London, released bumblebees (Bombus terrestris) onto fields of cotton two weeks after they had been sprayed with sulfloxaflor. After two to three weeks, there were fewer workers in colonies exposed to the pesticides compared with those just fed sugar syrup. After nine weeks, exposed colonies had 54% fewer new queens and males than the controls.

The results indicate that the use of sulfoximines as direct replacements for neonicotinoids should be approached with caution.


Siviter, H, et al (2018). Sulfoxaflor exposure reduces bumblebee reproductive success. Nature.

Why Bees Become Aggressive

In a study designed to try to identify why some honey bees are more aggressive than others, the production mechanism of neurohormones in the brain was studied by researchers at São Paulo State University, Brazil. When they were 20 days old, marked Africanized honey bee workers were stimulated to attack and sting leather targets. Those that stung were captured and immediately frozen in liquid nitrogen. Bees not showing aggressive behaviour were also captured. Slices from the brains of both sets were submitted to MALDI spectral imaging analysis. The precursor proteins in the brains of the non-aggressive bees were found to be intact in their inactive form, meaning these substances didn’t stimulate aggressive behaviour. The neuropeptides identified in the aggressive bees were injected into young workers not yet old enough to show aggression. These bees quickly showed aggressive behaviours indicating the neuropeptides could be the source of aggressiveness.


Pratavieira, M, et al (2018). MALDI Imaging Analysis of Neuropeptides in Africanized Honeybee (Apis mellifera) Brain: Effect of Aggressiveness. Journal of Proteome Research, 17(7), 2358–2369. doi: 10.1021/acs.jproteome.8b00098

The Best Raspberry Pollination?

Raspberry flower morphology prevents complete auto-pollination which requires pollinators. Using honey bees is becoming more expensive, so raspberry farms are  investigating the use of other pollinators. To be justified, on a cost per forager basis, there must be an added advantage such as superior pollination efficacy.

Researchers at Utah State University, USA, compared the pollination efficacy of honey bees with that of various Bombus species, and three Osmia solitary bees. The number of individual drupelets on a fruit resulting from a single visit to a virgin flower were compared. The pollination efficacy was also compared between unvisted and hand-pollinated flowers. All five bee species were equally effective pollinators but bumblebees and mason bees are more effective during cool weather or plants cultivated under cover.


Adrikopoulos, CJ and Cane, JH (2018). Comparative Pollination Efficacies of Five Bee Species on Raspberry. Journal of Economic Entomology, toy226,

The Sting in the Tail

Many studies have concentrated on the pain inflicted by a sting but researchers at Utah State University have compared the relative sting length (compared to body size) of species from 14 families of bees, wasps and ants. Sting length is also compared to the pain and toxicity values of each sting.

Insects with larger stings were likely to inflict greater pain but no link was established between the relative sting length and pain. There was an inverse relationship between relative sting length and toxicity where insects with shorter stings delivered more toxins. No significant relationship was determined between venom lethality and reported pain of the sting.


Sadler, EA, et al (2018). Stinging wasps (Hymenoptera: Aculeata): which species have the longest sting? PeerJ, 6:e4743.

Article Appears in the November 2018 Edition of Bee Craft Magazine

« Back