Welcome to the Nieh Lab

Bee health

Bee health and conservation is an issue that affects many bee species, including native bees. What can you do? Learn about how to identify bee species, create bee-friendly gardens and habitats, and follow practices that help bees and other insect pollinators. This zip file contains multiple resources, including identification guides, that have been consolidated from the Xerces society website. Much of the information in this file is local and focused on Southern California, but the Xerces society and other groups have information for many different regions in the USA.

Our lab is actively studying the effects parasites and pesticides on honey bee health, two factors that are thought to play a roles in honey bee declines. The microsporidian parasite, Nosema, poses a major problem for honey bee health and is associated with poor honey bee health. Currently, we are studying the effect of Nosema ceranae at different doses on the growth, development, and adult behaviors of honey bee larvae. In the video below, you will see an example of the behavior of honey bee larvae recorded inside an incubator. If you look closely on the right side, you will see movements of the larvae, which have been sped up. We plan to use this setup to study the effects of Nosema infection on honey bee larval behavior and nurse bee behavior


Nosema ceranae spores (green ovals) photographed on a hemocytometer under a light microscope at 400x. The inset photo shows a honey bee larvae in comb.

Our research on pesticides focuses on the effects of neonicotinoid pesticides. We are interested in (1) how bees are exposed to neonicotinoids, (2) how these compounds affect their willingness to forage, and (3) how it affects their navigation and learning

Relatively little is know about the effects of pesticides on bees apart from the European honey bee. Part of research therefore focuses on other species, including economically and ecologically important Asian honey bee species (Tan, K., Chen, W., Dong, S., Liu, X., Wang, Y., and Nieh. J.C. (2014) Imidacloprid alters foraging and increases risky behavior in bees. PLOS One. 9(7): e102725.).

Imidacloprid affects the sucrose response threshold of honey bees and how bees are able to resist this pesticide. Natural nectar sources vary in their concentration of sugars. Each forager has a minimum threshold, the lowest concentration of sugar that she will feed upon. In the lab, harnessed foragers are given a sequence of increasing sucrose concentrations and the lowest sucrose concentration that will elicit feeding (proboscis extension) is the sucrose response threshold. Thus far, our experiments reveal that sublethal doses of imidacloprid can elevate this response threshold. As a result, bees become like “picky eaters,” only feeding on higher sucrose concentrations than control bees. If such bees forage less and reject more natural nectar sources, less food would flow into the nest. Tested 24 hrs after treatment, pesticide-treated foragers accepted all offered sucrose concentrations but waggle danced (recruited) significantly less than controls. Overall, these changes may reduce food flow into the colony (Eiri and Nieh, 2012).

Related news

The following news articles have been published in the media based upon Eiri and Nieh (2012) and a UCSD press release issued for this paper. We provide them below, but wish to note that the most accurate interpretation of Nieh and Eiri (2012) is obtained from the paper itself. Statements and claims made in these news articles have not been verified by D. Eiri or J. Nieh.

Mongabay.com (2012) (pdf archive file) After damning research, France proposes banning pesticide linked to bee collapse.

NSF (2012) (pdf archive file) Crop pesticide's impact on honey bees (NSF news).

wired.com (2012) (pdf archive file) Pesticides make honeybees picky eaters and reluctant dancers (Wired UK).

MailOnline (2012) (pdf archive file) Pesticide kills bee colonies by turning insects into ‘picky eaters’ who crave sweeter nectar - and ignore nearby food.

redorbit.com (2012) (pdf archive file) Pesticide Turns Bees Into Picky Eaters - Science News.

sciencedaily.com (2012) (pdf archive file) Commonly used pesticide turns honey bees into ‘picky eaters'.

westernfarmpress.com (2012) (pdf archive file) Pesticide affects honey bee feeding habits.

beyondpesticides.org (2012) (pdf archive file) Beyond Pesticides Daily News Blog » Blog Archive » Research Shows Imidacloprid Depresses Honey Bee Feeding and Communication.

enewspf.com (2012) (pdf archive file) Research Shows Imidacloprid Depresses Honey Bee Feeding and Communication.

esciencenews.com (2012) (pdf archive file) Commonly used pesticide turns honey bees into ‘picky eaters’.

phys.org (2012) (pdf archive file) Commonly used pesticide turns honey bees into ‘picky eaters’.

wildlifenews.co.uk (2012) (pdf archive file) Common pesticide gives bees a sweet-tooth.

scientias.nl (2012) (pdf archive file) Bestrijdingsmiddel maakt honingbij tot een kieskeurige eter.

tech.money.pl (2012) (pdf archive file) Pestycyd sprawia, że pszczoły stają się wybredne.

tw.news.yahoo.com (2012) (pdf archive file) Pesticides make bees 'picky eaters' (Chinese language publication).

What's next?

Interestingly, winter foragers are more resistant to the effects of imidacloprid than summer foragers. This may be related the presence of elevated levels of the egg precursor protein vitellogenin, which is significantly higher in winter than summer bees and which is associated with bee longevity, health, and immunity. Lee BenVau is currently investigating this phenomenon.

We will also continue to investigate the behavioral effects of pathogens and pesticides, using flight mills to determine how these stressors affect honey bee flight, essential for colony food collection and for mating of virgin queens.

Learn more about the study of Trophic Interactions and Animal Behavior at UCSD.

Information for San Diegans

Are you a beekeeper with questions about local bees? The San Diego Beekeeping Society has great information for you. This group meets regularly and welcomes new members.

Do you have a swarm or a colony that you would like humanely removed rather than exterminated? This site has a list of people who can help you out.

Would you like to learn more about honey bee disease and parasites? This Penn State site has a document, A field guide to honey bees and their maladies that has great information and detailed photos.

Useful Links

Global declines in multiple bee species have been much in the news. Bees are important pollinators of agricultural crops as a keystone pollinators in multiple ecosystems. Much attention has been given in the press to Colony Collapse Disorder, which has led to declines in the honey bee population. However, this is part of a larger overall decline in pollinators. The following links provide useful information and other resources if you are interested in learning more about these problems. Find out what you can do to help pollinators.

Questions about Colony Collapse Disorder? the Mid-Atlantic Apiculture Research and Extension Consortium website has some of the best information about Colony Collapse Disorder, including documents from the US Working Group on Colony Collapse Disorder.

How can you help protect and promote pollinators? The Pollinator Partnership has highly useful information and brochures on how you can promote healthy habitats for bees. Their "Useful Resources" links is a particulately good place to look for more information.

What about native bees? The Xerces Society has excellent information about native bees such as bumble bees. These native species are also declining.

Help support research on honey bee declines

Please visit our online donation website. Thank you for your support!


Please note: The copyright of these articles (with the exception of Open Access articles) is with their respective publishers. By downloading an article, you agree to limit the use of the pdf file to printing of single copies for personal research and study. You may not modify the files in any way, or to use them for commercial purposes.

Eiri D, Nieh JC (2012) A nicotinic acetylcholine receptor agonist affects honey bee sucrose responsiveness and decreases waggle dancing. Journal of Experimental Biology. 215:2022-2029.