The presence of antimicrobial secondary metabolites in nectar suggests that pollinators, which are threatened globally by emergent disease, may benefit from the consumption of nectars rich in these metabolites. We tested whether @entity1239 , a nectar secondary metabolite common in Solenaceae and Tilia species, is used by parasitized bumblebees as a source of self-medication , using a series of toxicological, microbiological and behavioural experiments. Caged @entity5157 infected with Crithidia bombi [TI1]  had a slight preference for @entity969 solution laced with the alkaloid and behavioural tests showed that the parasite @entity281 induced an increased consumption of @entity1239 during foraging activity. When ingested, @entity1239 delayed the progression of a gut @entity281 in bumblebees by a few days, but dietary @entity1239 did not clear the @entity281 , and after 10 days the parasite load approached that of control @entity5157 . Moreover, when pathogens were exposed to the alkaloid prior to host ingestion the protozoan's viability was not directly affected, suggesting that anti-parasite effects were relatively weak. @entity1239 consumption in a single dose did not impose any cost even in food-stressed @entity5157 (starved) but the alkaloid had detrimental effects on healthy @entity5157 if consistently consumed for weeks. These toxic effects disappeared in infected @entity5157 suggesting that detoxification costs might have been counterbalanced by the advantages in slowing the progression of the @entity281 . Nonetheless we did not find a benefit of @entity1239 consumption in terms of life expectancy of infected @entity5157 , making these findings difficult to interpret. Our results indicate that caution is warranted in interpreting impacts of plant metabolites on insect parasites and suggest that the conditions under which @entity1239 consumption provides benefits to either @entity5157 or plants remain to be identified. The contention that secondary metabolites in nectar may be under selection from pollinators, or used by plants to enhance their own reproductive success, remains to be confirmed.

Weak and contradictory effects of self-medication with nectar XXXX by parasitized bumblebees.

@entity969 :: ('MESH:D013395', 'Chemical') :: ['sucrose'] @entity1239 :: ('MESH:D009538', 'Chemical') :: ['Nicotine', 'nicotine'] @entity281 :: ('MESH:D007239', 'Disease') :: ['infection'] @entity5157 :: ('7460', 'Species') :: ['bees']
@entity1239 :: (MESH:D009538,Chemical) :: ['nicotine']
