Flower Microbiomes and Bee Visitation Patterns

ISEF Category: Microbiology

Subcategory: Environmental Microbiology  ·  Difficulty: Intermediate  ·  Setup: School Lab  ·  Time: 1 to 2 Months

The Hook

A flower can be a tiny city. Its nectar feeds microbes, and those microbes can change how bees behave. If pesticides alter that community, the effect can ripple from a single blossom to an entire garden. You can test that link with sampling, culturing, and video data.

What Is It?

This project asks whether the tiny living community inside flower nectar changes along a pesticide-use gradient, and whether those changes connect to bee visits. Nectar is not sterile sugar water. It can hold yeasts, bacteria, and other microbes that grow, compete, and affect scent and sugar chemistry. Think of each flower like a shared lunch table. The mix of microbes at that table can change the meal.

You would compare flowers from places with different pesticide histories, such as a community garden and a conventional planting area. Then you would culture nectar microbes like yeasts and Lactobacillus, count colonies, and describe the types you recover. At the same time, you would record bee visitation with time-lapse video. That gives you two linked datasets, one for the microbe community and one for pollinator behavior.

Why This Is a Good Topic

This is a strong science fair topic because you can measure a real ecological relationship with tools a student can actually access. You are not just describing flowers, you are testing whether environmental management changes a microbial community and whether that community lines up with bee behavior. That connects to pollinator health, pesticide exposure, and urban ecology. You can learn field sampling, microbial culture, image-based observation, and basic statistics in one project.

Research Questions

• How does pesticide-use history affect the abundance of culturable nectar yeasts and Lactobacillus?
• What is the effect of garden type, community garden versus conventional planting, on nectar microbial diversity?
• Does higher nectar yeast abundance predict more bee visits per flower hour?
• To what extent does nectar microbial composition differ between flower species grown at the same site?
• Which environmental variable, pesticide-use history, flower species, or site type, best predicts bee visitation?
• How does nectar sugar concentration relate to the culturable microbe count in sampled flowers?

Basic Materials

• Sterile microcentrifuge tubes for nectar collection.
• Sterile swabs or capillary tubes for nectar sampling.
• Disposable gloves and ethanol spray for field hygiene.
• Portable cooler with ice packs for sample transport.
• Petri dishes, growth media, and inoculation tools for basic culture work.
• Incubator or warm school-lab space with controlled temperature.
• Compound microscope for viewing colonies or cell morphology.
• Digital camera or phone tripod for time-lapse video.
• Weather notebook or field data sheet.
• Sucrose refractometer or handheld Brix meter for nectar sugar measurements.

Advanced Materials

• Laminar flow hood for cleaner plating and transfers.
• Autoclave or pressure sterilizer for media preparation.
• Selective and differential media for yeast and lactic acid bacteria.
• Colony counter or imaging setup for plate quantification.
• qPCR access for microbe detection and confirmation.
• DNA extraction kit for culture-independent follow-up work.
• PCR thermocycler and gel electrophoresis setup.
• Microscope with phase contrast or fluorescence, if available.
• Environmental data logger for temperature, humidity, and light.
• High-resolution camera and fixed stand for standardized bee video.

Software & Tools

• ImageJ: Measures colony area, counts bees in frames, and helps standardize image analysis.
• Python: Organizes data, runs statistics, and makes plots for microbial counts and visitation rates.
• R: Fits models that test whether microbial patterns predict bee behavior.
• OBS Studio: Records fixed-camera time-lapse video from a stable setup.
• Google Sheets: Keeps field notes, plate counts, and sample metadata in one place.

Experiment Steps

1. Define your comparison groups, such as community garden and conventional sites, and decide which flower species you will sample at each site.
2. Choose one response variable for the microbes, such as colony count, colony type count, or a simple diversity index.
3. Plan how you will standardize nectar collection, video framing, and sampling timing so site differences do not blur the signal.
4. Build a data table that links each flower sample to its video record, flower species, site type, and pesticide-use history.
5. Select controls that separate site effects from flower-species effects, then plan a way to compare them statistically.
6. Decide how you will test whether microbe patterns predict bee visitation, using correlation, regression, or a mixed model.

Common Pitfalls

• Sampling different flower species at each site, which makes site effects impossible to separate from plant effects.
• Letting nectar samples sit too long before plating, which can change the live microbe mix.
• Counting every colony as a different organism without checking colony appearance, which inflates diversity estimates.
• Filming bee visits with changing camera distance or lighting, which makes visitation counts hard to compare.
• Treating one garden as proof of pesticide effects, which leaves you with a site comparison instead of a real gradient test.

What Makes This Competitive

A stronger project will go beyond a simple before-and-after comparison. You can improve it by sampling more than one flower species, recording real pesticide-use history, and separating site effects from plant effects in your analysis. A competitive entry also uses careful video scoring and a clear statistical test, not just a visual impression. If you add a culture-independent check, like DNA-based confirmation of the main microbes, your story becomes much stronger.

Project Variations

• Focus only on native flowers versus ornamental flowers to see whether plant type changes nectar microbiomes.
• Swap culturing for DNA-based barcoding of nectar microbes if your school lab has PCR access.
• Compare bee visitation on irrigated and non-irrigated sites to test whether water stress shifts nectar microbes and pollinator activity.

Learn More

• NIH PubMed: Search review articles on nectar microbes, pollinator health, and flower visitation patterns.
• NOAA Climate.gov: Use background climate data to think about temperature, humidity, and pollinator activity.
• USDA Agricultural Research Service: Find articles on pollinators, pesticide exposure, and crop ecology.
• Applied and Environmental Microbiology: Search for studies on environmental yeast and bacterial communities in nectar.
• University OpenCourseWare in ecology or microbiology: Use free lecture notes to review sampling design and basic microbial ecology.
• NASA Earthdata: Explore local environmental context, such as land use and habitat patterns, when comparing field sites.