Bumblebees that have been infected by parasites seek out flowers with nicotine in the nectar, says a group of scientists from Royal Holloway University of London and Queen Mary University of London, UK.
The buff-tailed bumblebee (Bombus terrestris). Image credit: Kintaiyo / CC BY 3.0.
In their experiments, reported in the journal F1000Research, the scientists gave buff-tailed bumblebees (Bombus terrestris) the option to choose between a sugar solution with nicotine in it and one without.
Those bumblebees infected with the Crithidia bombi parasite were more likely to go for the nicotine-laced nectar than those that weren’t infected.
Infected bumblebees that consumed nicotine delayed the progress of the infection for a few days, showing lower levels of parasites than those that had not.
However, it did not increase the life expectancy of those bumblebees, meaning that the direct benefits of nicotine for the colony remain to be identified.
Consuming nicotine also had negative effects, appearing to suppress the appetite of infected bumblebees much like smoking does in humans.
Healthy bumblebees that consumed nicotine also showed shorter lifespans than those that did not consume any.
Bumblebees are not the only creatures known to use nicotine to fight parasites, with house sparrows using cigarette butts in their nests to ward off mites.
“While it’s clear that there is some benefit to nicotine consumption for parasite-infected bumblebees, a key challenge now is to discover exactly how such natural medication limits the impact of the disease on the bumblebees’ society. Given the stresses placed on worldwide bee populations by disease, understanding how the bumblebees themselves fight infection is key,” said Dr David Baracchi from Queen Mary University of London, the lead author on the study.
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Baracchi D et al. 2015. Weak and contradictory effects of self-medication with nectar nicotine by parasitized bumblebees. F1000Research 4: 73; doi: 10.12688/f1000research.6262.1
