An Analysis of Possible Causes of

Worldwide Honey bee (Apis

mellifera L.) DeclineJonathan Spence

The honey bee (Apis mellifera L.)• What is a honey bee? -A stinging insect that collects nectar and pollen - Most notable for it’s ability to make honey - Honey bee hive consist of workers, drones, and a queen. - Up to 60,000 honey bees in a single hive

Why are honey bees important?• Honey bees contribute 10-33 billion dollars annually to

the United States economy. • Honey bees are responsible for about 80% of total

pollinating insects of major crops. • Agriculture - Almonds, apples, avocados, blueberries, cranberries, cherries, kiwi fruit, macadamia nuts, asparagus, broccoli, carrots, cauliflower, celery, cucumbers, onions, legume seeds, pumpkins, squash, and sunflowers are 90%-100% dependent on honey bee pollination. • Important for ecosystem

History of Declines • From 1947-2005 a decrease from about 6 million hives

to 2.5 million

Figure 1. U.S. honey bee colonies, 1945–2005. Data compiled from USDA-NASS

Figure 2. Bar graph representing losses from 2006-2015 annually. Bar graph represents accepted annual loss, winter loss, and total annual loss. (Steinhauer et al. 2015)

• From 2006-2015 an average of 28.7% loss annually

• Highest annual loss seen in 2012/2013 of 45%

• 2014/2015 a loss of about 43% annual loss

• Personally lost 40% of hives in 2015/2016

• Above acceptable rate of about 15% annually

What could be causing honey bee declines?

Three potential reasons:1. Pesticides

2. Mites 3. Viruses

Pesticides • Pesticide- a substance used for killing/repelling insects • Honey bees can be exposed: - If present at time of application - By nectar and/or pollen • Honey bees bring pesticides back to hive

Pesticides found in hive• Mullin et al. (2010) found that on average there are: - Samples taken from 23 states and one Canadian province totaling 887 beehives sampled -60% of wax and pollen samples had at least one pesticide - An average of 7 pesticides found in pollen samples - Honey bees generally have lower pesticide levels

Affects of Pesticides on Honey Bees

• Han et al. (2010) conducted research to see how pesticides affect honey bees

• Placed honey bees in T-tube maze that was color coded and had sucrose on one side

- Blue used to test learning capability. - Attracted to smell of sucrose - Exposed for 7 days prior to test

• Only about 40% of pesticide exposed honey bees made the correct decision. N=80 per session • Decrease foraging efficiency could ultimately be the

cause of a decline in hive populations • Decrease in visual and smell learning capacities

Findings of Han et al. (2010)

Mites • Two types 1. Varroa mites (Varroa destructor)2. Tracheal mites (Acarapis woodi) -Ectoparsites - Same family as ticks -Can live off all honey bees

Varroa mite • Found worldwide • Known to be main cause of honey bee colony collapse

worldwide • Out of 400 colonies sampled in Ontario Canada 75%

were infested • Leading cause of colony deaths from samples taken in

Ontario Canada - more than 85%

Tracheal mite• Lives inside of honey bee until mature• Can affect honey bees ability to thermoregulate • Can cause flight muscles to deteriorate • Not as common • Can vector viruses

Viruses • sacbrood virus (SBV)• chronic bee paralysis virus (CBPV)• black queen cell virus (BQCV)• deformed wing virus (DWV)• acute bee paralysis virus (ABPV) • kashmir bee virus (KBV)

• No vaccines or medications are available for any of the honey bee viruses

Viruses• Most common viruses found - BQCV 30%- 85% - DWV 80%-91%

Honey bee with DWV

Healthy Honey bee

Overall Findings • Pesticides found in hives and can affect honey bees

ability to forage• Varroa mites found in more than 75% of hive samples

and are known to be the main cause of colony collapses.• Tracheal mites not as common but cause increased

winter losses by limiting the honey bees ability to thermoregulate • BQCV and DWV were the most prevalent viruses • Combination of all factors causing declines

What can be done?• Get involved! Get a honey bee hive • Educate beekeepers on what is causing honey bee

declines and what they can do to prevent losing colonies • Funding for beekeepers and those wanting to become

beekeepers - currently cost about $500.00 to get started in beekeeping. Only 1 hive• Limit use of pesticides, research pesticides that are less

harmful • Focus research on other honey bee species that could

better combat causes of honey bee declines.

Literature cited • Arena, M., and F. Sgolastra. 2014. A meta-analysis comparing the sensitivity of bees to pesticides. Ectoxicology 23:324-334.• Berenyi, O., T. Bakonyi, I. Derakhshifar, H. Koglberger, and N. Nowotny. 2006. Occurrence of six honeybee viruses in diseased Austrian apiaries.

Applied and Environmental Microbiology. 72:2414-2420. • Chen, Y.P., J.S. Pettis, M. Corona, W. Ping Chen, C. Jun Li, M. Spivak, P.K. Visscher, G. DeGrandi-Hoffman, H. Boncristiani, Y. Zhao, D.

vanEngelsdorp, K. Delaplane, L. Solter, F. Drummond, M. Kramer, W.I. Lipkin, G. Palacios, M.C. Hamilton, B. Smith, S. Kang Huang, H. Qing Zheng, J. Lian Li, X. Zhang, A. Fen Zhou, L. You Wu, J. Zhong Zhou, M.L. Lee, E.W. Teixeira, Z. Guo Li, and J.D. Evans. 2014. Israeli Acute Paralysis Virus: Epidemiology, Pathogenesis and Implications for Honey Bee Health. PLOS Pathogens 10: 1-15.

• Christopher, A.M., M. Frazier, J.L. Frazier, S. Ashcraft, R. Simonds, D. vanEnglsdorp and J.S. Pettis. 2010. High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health. PLOSOne 5:1-19.

• Cornman, R.S., D.R. Tarpy, Y. Chen, L. Jeffreys, D. Lopez, J.S. Pettis, D. vanEngelsorp, and J.D. Evans.2012. Pathogen Webs in Collapsing Honey Bee Colonies. PLOSOne 7:1-15.

• Genersch, E. 2010. Honey bee pathology: current threats to honey bees and beekeeping. Appl Microbiol Biotechnol. 87:87-97. • Han, P., C.Y. Niu, C.L. Lei, J.J. Cui, and N. Desneux. 2010. Use of an innovative T-tube maze assay and the proboscis extension response assay to

assess sublethal effects of GM products and pesticides on learning capacity of the honey bee Apis mellifera L. Ecotoxicology 19:1612-1619. • Highfield. A.C., A.E. Nagar, L.C.M. Mackinder, M. Laure, J. Noel, M.J. Hall, S.J. Martin, and D.C. Schroeder. 2009. Deformed wing virus implicated

in overwintering honey bee colony losses. Applied and Environmental Microbiology. 75:7212-7220.• Johnson, R. 2010. Honey Bee Colony Collapse Disorder. Congressional Research Service 1-17.• Johnson, R.M., M.D Ellis, C.A. Mullin, and M. Frazier. 2010. Pesticides and honey bee toxicity- USA. Apidologie 41:312-331. • Kojima, Y., T. Toki, T. Morimoto, M. Yoshiyama, K. Kimura, and T. Kadowaki. 2011. Infestation of Japanese native honey bees by tracheal mite

and virus non-native European honey bees in Japan. Microb Ecol. 62:895-906.

• McMullan, J.B., and M.J. Brown. 2009. A qualitative model of mortality in honey bee (Apis melliffera) colonies infested with tracheal mites. Exp Appl Acarol. 47:225-234.

• Moore, P.A., M.E. Wilson, and J.A. 2015. Skinner. Honey bee viruses, the deadly varroa mite associates. Bee Health. 1-12. • Mullin, C.A., M. Frazier, J.L. Frazier, S. Ashcraft, R. Simonds, D. vanEngelsdorp, and J.S. Pettis. 2010. High levels of miticides and agrochemicals in

North America apiaries: Implications for honey bee health. PLOSone 5:1-19. • Pettis, J.S., D. vanEngelsddorp, J. Johnson, and G. Dively. 2012. Pesticide exposure in honey bees results in increased levels of the gut pathogen

Nosema. Naturwissenschaften 99:153-158. • Pettis, J.S., R. Rose, E.M. Lichtenberg, P. Chantawannakul, N. Buawangpong, W. Somana, P. Sukumalanand, and D. vanEngelsdorp. 2013. A Rapid

Survey Technique for Tropilaelaps Mite (Mesostigmata: Laelapidae) Detection. Apiculture and Social Insects 106: 1535-1544. • Rose, R., J. Pettis, K. Rennich, and D. vanEngelsdorp. A US national survey of honey-bee pests and diseases. (Journal, volume not specified) 1-4. • Rycke, P.H., J.J. Joubert, S.H. Hosseinian, and F.J. Jacobs. 2002. The possible role of Varroa destructor in the spreading of American foulbrood

among apiaries. Experimental and Applied Acarology. 27:313-318. • Singh, R., A.L. Levitt, E.G. Rajotte, E.C. Holmes, N. Ostiguy, D. vanEngelsdorp, W.I. Lipkin, C.W. dePamphilis, A. L. Toth, and D.L. Cox-Foster. RNA

Viruses in Hymenopteran Pollinators: Evidence of Inter-Taxa Virus Transmission via Pollen and Potential Impact on Non-Apis Hymenopteran Species. 2010. PLOS One 5:1-16.

• Steinhauer, N., K. Rennich, K. Lee, J. Pettis, D.R. Tarpy, J. Rangel, D. Caron, R. Sagili, J.A. Skinner, M.E. Wilson, J.T. Wilkes, K.S. Delaplane, R. Rose, and D. vanEngelsdorp. 2015. Colony loss 2014-2015: Preliminary results. Bee Informed Partnership. 1-5

• vanEngelsdorp, D., J.D. Evans, C. Saegerman, C. Mullin, E. Haubruge, B.K. Nguyen, M. Frazier, J. Frazier, D. Cox-Foster, Y. Chen, R. Underwood, D.R. Tarpy, and J.S. Pettis. 2009. Colony Collapse Disorder: A Descriptive Study. PLOS ONE 4:1-17.

• vanEngelsdorp, D., N. Speybroeck, J.D. Evans, B. Kim Nguyen, C. Mullin, M. Frazier, J. Frazier, D. Cox-Foster, Y. Chen, D.R. Tarpy, E. Haubruge, J.S. Pettis, and C. Saegerman. 2010. Weighing Risk Factors Associated With Bee Colony Collapse Disorder by Classification and Regression Tree Analysis. J. Econ. Entomol. 103:1517-1523.

Thanks to…• Dr. Pearson • Dr. Rockel• Dr. Soper Gorden • Mitchell Blackmon • Megan Maddox

Questions?