Abstract
Bumblebee colonies are founded by a single-mated queen. Due to this life history trait, bumblebees are more susceptible to parasites and diseases than polyandrous and/or polygynous social insects. A greater resistance towards parasites is shown when the genetic variability within a colony is increased. The parasite resistance may be divided into different levels regarding the step of the parasite infection (e.g. parasite uptake, parasite intake, parasite's establishment in the nest, parasite transmission).We investigate the prophylactic behaviour of bumblebees. Bumblebees were observed during their foraging flights on two artificial flowers; one of these was contaminated by Crithidia bombi, a naturally occurring gut parasite of bumblebees (in a control experiment the non-specific pathogen Escherichia coli was used). For C. bombi, bumblebees were preferentially observed feeding on the non-contaminated flower. Whereas for E. coli, the number of visits between flowers was the same, bumblebees spent more time feeding on the non-contaminated flower.These results demonstrate the ability of bumblebees to recognise the contamination of food sources. In addition, bumblebees have a stronger preference for the non-contaminated flower when C. bombi is present in the other flower than with E. coli which might be explained as an adaptive behaviour of bumblebees towards this specific gut parasite. It seems that the more specific the parasite is, the more it reduces the reward of the flower.
Highlights
Among all metazoans, parasites and diseases represent a strong threat reducing the life time and the fitness of an organism [1], and a strong evolutionary force [2]
The proportion of visits on the uninfected flower is higher for the C. bombi experiment than for the E. coli one
This proportion was lower than for either of the other experiments (Fig1, GLMM: p,0.001). This highlights an increased preference, or a better ability to avoid the contaminated flower, in the presence of C. bombi than E. coli (C. bombi vs control: p,0.001, C. bombi vs E. coli: p,0.001, E. coli vs control: p,0.01)
Summary
Parasites and diseases represent a strong threat reducing the life time and the fitness of an organism [1], and a strong evolutionary force [2]. When a parasite is specific to a host, the relation, regarding the evolution, between these two species is linked and may lead to co-evolution. This co-evolution between a parasite and a host results in an arms race [3,4]. The host will tend to evolve to reduce the effects of the parasites on themselves. The first one is the reduction of parasite uptake, allowing individuals to avoid the parasite. The third one is the reduction of parasite loads inside the host and even the complete elimination of the parasite. The last level is the prevention of transmission of the parasite in order to avoid secondary infection and the infection of the conspecifics
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call