The Effects of Fungicides on Bumble Bee Colonies | HHMI BioInteractive Video

Summary

This video explores the hidden dangers of fungicides to native bee populations. Conservation photographer Clay Bolt investigates the relationship between bees and the fungi that help preserve their food supply. Through an experiment led by entomologist Shawn Steffan, it’s revealed that fungicides, when sprayed on flowers, can significantly harm bumblebee larvae, leading to colony decline. The study underscores the need for more research on the impact of different fungicides on bees and suggests that altering the timing of fungicide applications could help protect pollinators.

Takeaways

• 😀 Fungicides, commonly used on crops, may have harmful effects on native bees, particularly bumblebees.
• 😀 Native bee species in North America are facing declines, and researchers are exploring the causes, including the impact of fungicides.
• 😀 Fungicides are not typically designed to harm bees directly, but their effect on fungi, which are crucial to bee diets, is being studied.
• 😀 Microorganisms like yeasts in pollen help preserve it and are vital for bee larvae development.
• 😀 The relationship between bees and fungi is integral to the bees' health, as they depend on fungi to preserve their food provisions.
• 😀 Researcher Shawn Steffan is investigating how fungicides might harm the fungi that bees rely on by analyzing bee nests and their contents.
• 😀 Yeast is a major component of bumblebee larvae's diet, and some species may consume pollen that's more yeast than pollen by the time they finish feeding.
• 😀 Fungicides in the environment may disrupt these fungal populations, potentially harming bee larvae and impacting colony health.
• 😀 In controlled experiments, bumblebee colonies exposed to fungicides showed significant declines in population compared to control colonies.
• 😀 The harmful effect of fungicides on bees appears to be indirect, affecting larvae through changes to their food sources, rather than directly harming adult bees.
• 😀 Shawn Steffan emphasizes the need for further research to understand how different fungicides affect various bee species and to develop guidelines for safer pesticide use.

Q & A

What is the main focus of Shawn Steffan's research?

Shawn Steffan's research focuses on understanding how fungicides may harm native bee species, particularly by disrupting the fungi in their diet, which are essential for preserving pollen provisions for bee larvae.

Why are fungicides a potential threat to bees, according to the research?

Fungicides can harm the fungi, such as yeasts, present in the pollen that bees collect. These fungi play a crucial role in preserving the pollen for bee larvae, and without them, the larvae may suffer.

How do fungi help bees in their diet?

Fungi help preserve the pollen collected by bees by fermenting it, preventing spoilage over several days. This preserved pollen mixture is crucial for feeding bee larvae.

What was the hypothesis that Shawn Steffan aimed to test?

Shawn Steffan hypothesized that fungicides could harm the yeast and other fungi in the pollen provisions, which in turn would negatively affect the development of bee larvae.

How did Shawn Steffan conduct his experiment to test the effects of fungicides on bee colonies?

Shawn Steffan placed 10 bumblebee colonies into outdoor cages with flowers, half of which were treated with fungicides. He observed the effects on colony size after a month.

What were the results of Steffan's experiment with fungicide-treated flowers?

The colonies exposed to fungicide-treated flowers showed a significant decline in colony size, averaging only 12 bees per colony, compared to 43 bees per colony in the control group.

Why is it significant that the fungicides were not applied directly to the bees?

The significance lies in the fact that the fungicides did not affect the adult bees directly. Instead, the harm was indirect, affecting the fungi essential for bee larvae, leading to a decline in colony health.

What does the research suggest about fungicides and their impact on bees?

The research suggests that certain fungicides, when applied to flowers, can negatively affect bee larvae by disrupting their fungal food sources, posing a hidden risk to pollinators.

How does this research affect the understanding of fungicides' role in agriculture?

This research highlights that fungicides might have unintended consequences for pollinators, urging agricultural practices to consider the indirect effects of fungicides on bee populations.

What are some possible solutions for reducing the harmful impact of fungicides on bees?

One solution is to apply fungicides before or after the bloom, when bees are not foraging on the flowers, to reduce their exposure to fungicide residues.