energetic stress as a potential cause of colony collapse disorder

1. Energetic stress as a potential cause of colony collapse disorder Christopher Mayack Department of Biology, Colorado State University Presented on March 25th 2009

3. Colony Collapse Disorder (CCD) Not the first time � since 1800�s (Underwood 2008) Parasites � N. ceranae (Higes et al. 2008) Pesticides - neonicotinoids (Aliouane et al. 2009) Nutrition - carbohydrates (Mayack and Naug 2009)

4. Nosema apis and Nosema ceranae Widespread microsporidian gut parasite of the honeybee N. ceranae recently jumped hosts from Apis cerana

5. Nosema apis and N. cerenae pathology Symptoms caused by lack of protein absorption Symptoms dysentery reduction in hypopharengeal gland accelerated age polyetheism cuts honeybee life-span in half foraging in poor weather conditions

6. Nosema infection and its relation to hunger

7. What is Risk-sensitivity Theory? Foraging animals have to make decisions Charnov�s classical Optimal Foraging Theory Homogenous food patches were assumed

8. Empirical evidence for risk-sensitivity theory Fish, mammals, and insects do not follow Charnov�s (1976b) model They exhibit risk-sensitive foraging

9. Energy-budget Rule Positive energy budget Risk-averse Negative energy budget Risk-prone

10. Risk-sensitive foraging in bumble bees Switched from risk-averse to risk-prone with energy budget manipulation Different food storage in comparison to honeybees Energy reserves � based on colony food stores

11. Risk-sensitive foraging in honeybees Studies have shown honeybees are risk-indifferent store food communicate the location of food sources colony needs versus individual needs

12. Connecting the dots: overview

13. Study Objectives Nosema causes an increase in hunger, appetite, and lowers survival Demonstrate that hungry bees exhibit risk-prone behavior Dissociate individual hunger from social hunger

14. Hypothesis 1 Nosema ceranae causes an increase in hunger, appetite, and lowers survival.

15. Summer of 2008 Monitored colonies for infection at two field sites Collected foragers Assayed infection with a hemacytometer

16. Setup of all three experiments

17. Measuring appetite Proboscis Extension Response (PER) Responsiveness test 0.1, 0.3, 1, 3, 10, 30% sucrose solution

18. Do infected foragers havea larger appetite?

19. Measuring the hunger levelof foragers Data recorded at 6 hour intervals for 24 hours Amount of 30% sucrose solution consumed over 24 hours

20. Are infected foragers hungrier than non-infected ones?

21. Monitoring survival of infected and uninfected foragers Data recorded at 6 hour intervals for 24 hours Feed each honeybee given amounts of 30 % sucrose solution in 5 �l, 10 �l, 20 �l, 30 �l amounts Survival and body temperature were recorded

22. Can infected foragers surviveas well as uninfected foragers?

23. Should hungry individuals be risk-prone?

24. Summary of results � Project 1 N. ceranae increases appetite and hunger in infected honeybees N. ceranae decreases survival rate of infected individuals Infected hungry individuals on a negative energy budget are likely to exhibit risk-prone behavior

25. Demonstrating risk-prone behavior � Project 2 set up

26. What we plan on seeing�

27. Dissociate individual hunger from social hunger� Project 3

28. Recording the artificial flower visits within one foraging bout After forager is trained to the bee-board Color preference will be recorded

29. Are hungry individualsin a satiated colony risk-prone?

30. Take Home Messages Nosema infection causes energetic stress in honeybees Energetically stressed honeybees prefer the risky, variable food source At risk of Starvation Hypothermia

31. Future Directions See if this risk-prone behavior is occurring out in the field Find ways to prevent forager starvation or hypothermia

32. Fingers are pointing to Nosema ceranae Higes et al. (2008, 2009) demonstrated collapse with Nosema ceranae Has found dead foragers out away from the hive that are highly infected No evidence of pesticides

33. Collaborative Project Proposal 1. Prevent Hypothermia

34. Overall Plan � Lets Work Together I would like to start Fall of 2009 For funding I am applying to a project Apis m. grant I am hoping to get 30 or more volunteer beekeepers

35. Set up, Materials, and Logistics Around 2 infected colonies from each volunteer To screen for infected colonies we can use one of the teaching lab rooms at Colorado State University I will train you on how to screen your hives for Nosema, this will take one day in the Fall of 2009

36. Monitoring colony populations Using a metal grid sample the bottom box 10 frames of bees, both sides Bees that take up a half square or more will count as 1 square. If weather does not permit for opening a hive I do not expect to collect data for these months

37. Details on the two treatments

38. Projected Results

39. Concluding Thoughts This would provide beekeepers a cheap feasible alternative to fumagillin Nosema may become resistant to fumagillin Increased hunger due to infection is a general mechanism and this may not only apply to Nosema, but to other infections as well

41. References Aliouane, Y., et al., 2009. Subchronic exposure of honeybees to sublethal doses of pesticides: effects on behavior. Environmental Toxicology and Chemistry. 28, 113-122. Barnard, C. J. & Brown, C. A. J. 1985. Risk sensitive foraging in common shrews (Sorex araneus L.). Behavioral Ecological and Sociobiology, 16, 161-164. Caraco, T., Martindale, S. & Whittam, T. S. 1980. An empirical demonstration of risk sensitive foraging preferences. Animal Behaviour, 28, 820-830. Cartar, R. V. 1991. A Test of Risk-Sensitive Foraging in Wild Bumble Bees. Ecology, 72, 888-895. Charnov, E. L. 1976a. Optimal foraging: Attack strategy of a mantid. American Naturalist, 110, 141-151. Charnov, E. L. 1976b. Optimal foraging: The marginal value theorem. Theoretical Population Biology, 9, 129-136. von Frisch, K. 1967. The Dance Language and Orientation of Bees. Cambridge, Massachusetts: Belknap Press. Hassanein, M. H. 1953. The influence of infection with Nosema Apis on the activities and longevity of the worker honeybee. Analytical Application of Biology, 40, 418-423. Higes, M., et al., 2009. Honeybee colony collapse due to Nosema ceranae in professional apiaries. Environmental Microbiology Reports. In Press. Higes, M., et al., 2008. How natural infection by Nosema ceranae causes honeybee colony collapse. Environmental Microbiology. 10, 2659-2669. Kacelnik, A. & Bateson, M. 1997. Risk-sensitivity: crossroads for theories of decision-making. Trends in Cognitive Sciences, 1, 304-309. Liu, T. P. 1984. Ultrastructure of the midgut of the worker honey bee Apis mellifera heavily infected with Nosema apis. Journal of Invertebrate Pathology, 44, 282-291.

42. References cont. Malone, L. A. & Gatehouse (nee Edmonds), H. S. 1998. Effects of Nosema apis infection on honey bee (Apis mellifera) digestive proteolytic enzyme activity. Journal of Invertebrate Pathology, 71, 169-174. Mattila, H. R. & Otis, G. W. 2006. Effects of Pollen Availability and Nosema Infection During the Spring on Division of Labor and Survival of Worker Honey Bees (Hymenoptera: Apidae). Environmental Entomology, 35, 708-717. Mayack, C., Naug, D., 2009. Energetic stress in the honeybee Apis mellifera from Nosema ceranae infection. Journal of Invertebrate Pathology. In Press. Moffet, J. O. & Lawson, F. A. 1975. Effect of Nosema-Infection on O2 Consumption by Honey Bees. Journal of Economic Entomology, 68, 627-629. Page Jr., R. E., Erber, J. & Fondrk, M. K. 1998. The effect of genotype on response thresholds to sucrose and foraging behavior of honey bees (Apis mellifera L.). Journal of Comparative Physiology A, 182, 489-500. Real, L. A. 1981. Uncertainty and pollinator-plant interactions: the foraging behavior of bees and wasps on artificial flowers. Ecology, 62, 20-26. Shafir, S., Wiegmann, D. D., Smith, B. H. & Real, L. A. 1999. Risk-sensitive foraging: choice behavious of honeybees in response to variability in volume of reward. Animal Behaviour, 57, 1055-1061. Shafir, S., Menda, G. & Smith, B. H. 2005. Caste-specific differences in risk sensitivity in honeybees, Apis mellifera. Animal Behaviour, 69, 859-868. Stephens, D. W. & Krebs, J. R. 1986. Foraging Theory. Princeton: Princeton University Press. Underwood, R., VanEngelsdorp, D., 2008. Colony Collapse Disorder: Have We Seen This Before? Bee Culture. In Press. White, G. F. 1919. Nosema disease. Bulletin of the U.S. Department of Agriculture, 1-59. Young, R. J., Clayton, H. & Barnard, C. J. 1990. Risk sensitive foraging in bitterlings, Rhodeus sericus: Effects of food requirement and breeding site quality. Animal Behaviour, 40, 288-297.

43. Picture Websites & References mainstusa.blogspot.com Higes et al. 2009 Springer Life Sciences www.geocities.com bumbleboosters.unl.edu www.foxnews.com chat.carleton.ca http://1.bp.blogspot.com/_uic7-mrnqss/SHFwXObRIzI/AAAAAAAAAFA/9NrjMLxA5UI/s400/DSC00634.JPG http://s3.amazonaws.com/pixmac-preview/businessmans-hand-pointing-finger-1.jpg http://laurablood.files.wordpress.com/2008/05/honey-bee.jpg