This study investigated pathogen transmission between pollinator species by collecting and screening 563 bee and wasp samples from 16 sites in North Central Florida. They tested for 13 pathogens, including viruses, bacteria, and microsporidia. They found that 60% of samples were associated with at least one pathogen, with 38% containing two pathogens. The most common pathogens were European foulbrood (21% of samples) and Nosema ceranae (18% of samples). Certain species had higher pathogen associations, such as the southeastern blueberry bee Habropoda laboriosa and European foulbrood. The results suggest pathogens can be transmitted horizontally between pollinator species while sharing flowers. Future work aims to determine

1. Ashlyn E. Wedde, Jason Graham, James D. Ellis
University of Florida
Department of Entomology & Nematology

2. Pollinators suffer from a myriad of pathogens
 Bacterial, fungal, and viral
Spread
 throughout a colony
 often to nearby colonies
 Pathogens = Colony losses

3. We rely on pollinator bee species for nearly 1/3 of our
entire food supply!

4. Durrer and Schmid-Hempel 1994
Sharing flowers
leads to horizontal
pathogen transmission

5.  Do pathogens spread across pollinator species?
Non-Apis bees and wasps (Hymenoptera) encounter
pathogens associated with honey bees while visiting
flowers

6.  WHO? Hymenopteran species (15)
 WHAT? Bees and wasps were collected from the
forage landscape and screened for pathogens
 WHERE? North central Florida sites (16)
 WHEN? Collections in 2012
 WHY? Bees & wasps encounter pathogens while
visiting flowers
 Are pathogens transmitted across pollinator species?
 HOW? Using molecular techniques to assess the
presence pathogens (13)

7. 16northcentralFloridasites

8.  Viruses:
 Acute Bee Paralysis
(ABPV)
 Black Queen Cell
 (BQCV)
 Chronic Bee Paralysis
 (CBPV)
 Deformed Wing (DWV)
 Israeli Acute Paralysis
(IAPV)
 Kashmir Bee (KBV)
 Sacbrood (SBV)
Other Pathogens:
 American Foulbrood
 European Foulbrood
 Chalkbrood
 Nosema apis
 Nosema bombi
 Nosema ceranae

9.  563 adult bee and wasp samples collected
 40%, n=227 samples were not affected by any
pathogens screened
 337 or 60% were associated with one or more of
the pathogens
 95 of those being honey bees
 About 38% (n=215) of the samples were
associated with 2 different pathogens

10. Co-infection Prevalence
Total samples
collected (n=563)
A. mellifera samples
(n=120)
Non-Apis samples
(n=443)
One pathogen 38% 215 33% 40 40% 175
Two
pathogens
15% 86 28% 34 12% 52
Three
pathogens
5% 28 13% 16 3% 12
Four
pathogens
1% 8 4% 5 1% 3
Five
pathogens
0% 0 0% 0 0% 0
Total positive
screens
60% 337 79% 95 55% 242

11. 0%
5%
10%
15%
20%
25%

12.  Pathogen frequency
varied
 sites
 different bee & wasp
species
 Hymenopteran
species had various
levels of association
with several
pathogens

13. Viruses associated by species

14. Pathogens associated by species

16.  Habropoda laboriosa, southeastern blueberry bee
 Bombus spp., bumble bee
 Camposomeris plumipes, scoliid wasp

18. Other pathogens
associated by species

21. Major species
associated with European foulbrood
 Habropoda laboriosa, southeastern blueberry bee
 Bombus spp., bumble bee
 Apis mellifera, honey bee

23.  European foulbrood (21%, n=121)
 65% (n=39) of the Habropoda laboriosa collected were
associated with European foulbrood
 N. ceranae (18%, n=100)
 Polistes dominula had the highest association with N.
ceranae, 55.6% (n=5) of collected individuals were
associated with N. ceranae
 DWV (16%, n=89)
 Over half Apis mellifera collected (51.3%, n=61) were
associated with DWV

24. Pathogen Species
Sites
(N)
Pathogen
Chalkbrood Ms, Hp, Dh, Vs, As 11
European Foulbrood Hl, Mq, As, Mc 2 ABPV, SbV
Nosema bombi Bs
Nosema ceranae
Bs, Cp, Hl, As, Am,
Vs, Mc, Mq
10
Black Queen Cell Virus Am 4 DWV, SbV
Deformed Wing Virus Am, Hp 3 BQCV
Israeli Acute Paralysis Virus Am 3 KBV
Prob > |t|, alpha > 0.05 for significance

25.  Vertical- passed to
offspring
 Horizontal-passed
between bees
 often within a colony
 Pollen
 Nectar
 Pests
 Mites, beetles
Foragers
(Chen et al., 2006)

26.  Horizontal transmission occurs in natural
populations
 Infections cross species
 Direction of transmission still unclear

27. Future Work
Are pathogens vertically transmitted?
 Virus Replication
 Viral Loads

28. Acknowledgemnts
Acknowledgments
Dr. Jamie Ellis
Dr. Jason Graham
Dr. Dan Schmehl
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Contact me: awedde@ufl.edu –Ashlyn Weddewww.UFhoneybee.com