Synergistic effects of floral phytochemicals against a bumble bee parasite. Issue 6 (15th February 2017)

• Record Type: Journal Article
• Authors: Palmer‐Young, Evan C.; Sadd, Ben M.; Irwin, Rebecca E.; Adler, Lynn S.
• Is Part Of: Ecology and evolution. Volume 7:Issue 6(2017:Apr.)
• Page Start: 1836
• Page End: 1849
• Publication Date: 2017-02-15
• Subjects: antimicrobial synergy -- bumblebee -- Crithidia bombi -- plant secondary metabolites -- pollinator–parasite interactions -- trypanosome; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.2794
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Floral landscapes comprise diverse phytochemical combinations. Individual phytochemicals in floral nectar and pollen can reduce infection in bees and directly inhibit trypanosome parasites. However, gut parasites of generalist pollinators, which consume nectar and pollen from many plant species, are exposed to phytochemical combinations. Interactions between phytochemicals could augment or decrease effects of single compounds on parasites. Using a matrix of 36 phytochemical treatment combinations, we assessed the combined effects of two floral phytochemicals, eugenol and thymol, against four strains of the bumblebee gut trypanosome Crithidia bombi . Eugenol and thymol had synergistic effects against C. bombi growth across seven independent experiments, showing that the phytochemical combination can disproportionately inhibit parasites. The strength of synergistic effects varied across strains and experiments. Thus, the antiparasitic effects of individual compounds will depend on both the presence of other phytochemicals and parasite strain identity. The presence of synergistic phytochemical combinations could augment the antiparasitic activity of individual compounds for pollinators in diverse floral landscapes. Abstract : Phytochemical mixtures are ubiquitous in plant species and communities. At a time when many pollinators are suffering disease‐related decline, our study shows that a combination of two floral phytochemicals synergistically inhibits the growth of a parasite of bumble bees. This research links existing work showing the benefits of individual phytochemicals and chemically complex foods against infection, and suggests that some phytochemical combinations could ameliorate infection in pollinators threatened by parasites, with implications for ecology, conservation, and agriculture.