Sunflowers, community ecology, and integrative biology

We are assessing the role of sunflower pollen (Helianthus annuus) for reducing pathogens in Bombus impatiens, the common eastern bumble bee, and Apis mellifera, the honey bee, in lab and field settings.

Following our surprising discovering that sunflower pollen dramatically and consistently reduces Crithidia bombi infection in B. impatiens (Giacomini et al. 2018) we have received multiple grants from the NIFA Pollinator Health program to explore the potential to use sunflower pollen and plantings as a strategy to improve bee health, and to understand the mechanisms underlying this effect.

Recent work by former graduate student George LoCascio includes documenting that multiple varieties, natural populations, congeners and even the distant relative goldenrod (Solidago) all have pollen that reduces C. bombi infection (LoCascio et al. 2019a), and that timing and dose affect the outcome of infection (LoCascio et al 2019b). Furthermore, farms with more sunflowers have commercial bumble bees with less infection and greater reproduction – so sunflowers benefit the common eastern bumble bees in natural settings (Malfi et al 2023). We’ve found little evidence that mechanisms are mediated by pollen chemistry (Adler et al 2020). Former graduate student Alison Fowler found few changes to bee immune function (Fowler et al. in 2022). Surprisingly, the effect is less strong in B. bimaculatus and B. vagans and nonexistent in B. griseocollis, suggesting a phylogenetic signal (Fowler et al. in 2022). Work in progress includes continuing to assess potential chemical and mechanical mechanisms, understanding the role of diet on the gut microbiome, and assessing the extent of the ‘medicinal’ effect across more bee and pathogen species. We have lots of idea for future directions!

Collaborators include Becky Irwin (NCSU), Quinn McFrederick (UC Riverside), Jay Evans (USDA), Phil Stevenson and Hauke Koch (Kew Gardens and University of Greenwich, UK), Ben Sadd (Illinois State University) and Kathy Bayliss (U Illinois). Current and recent members of the Adler lab involved in this work include postdoc Rosemary Malfi, graduate students Alison Fowler and Carolina Muñoz, and independent undergraduate research by Patrick Anderson, Lily Coppinger, Pheobe Deneen, Stephanie Lopez, Rachel Yost, Justin Roch and Cameron Lamphere.

In addition, Lynn Adler is the lead PI on a new NSF Integrative Biology grant, “Integrating molecular, cellular, organismal and community scales to understand how plants structure pollinator-pathogen dynamics.” Our goal is to understand how sunflower and other pollens affect pathogens and infection outcomes and pathogen dynamics at levels from molecular to landscape. We are collaborating with molecular biologist Megan Povelones (Villanova University), biochemists Phil Stevenson and Hauke Koch (Kew Gardens and University of Greenwich, UK), theorist Chris Myers (Cornell), and ecologists Laura Figueroa (UMass Amherst), Becky Irwin (NCSU), and Shalene Jha (U Texas Austin). We are also working with Enrique Suárez (UMass Amherst School of Ed) to develop inclusive STEM after-school programs for middle-school girls in conjunction with Eureka!

We have several exciting new results  and experiments in progress. Stay tuned for updates!