November : “Bumble Bees & Goldenrod”

This month we highlight our native bumble bees and goldenrod.  Goldenrod is just one of the native flowers that bumble bees visit.  Since it is a late summer blooming plant, it allows these pollinators to forage well into autumn when other flowers have stopped blooming.  For more information on goldenrod, https://www.fs.usda.gov/wildflowers/plant-of-the-week/solidago_altissima.shtml

Bumble bees are tiny super heroes.  

  1. Flight-Not only can bumble bees fly, they can fly backwards and hover!  They flap their wings 200 times per second allowing them to move in many wind conditions including turbulence, even though their bodies are large relative to their wings.

Scientists are researching bee flight to learn how to create better drones. https://physics.aps.org/articles/v9/6

  1. Sight– They can see ultraviolet light, which the human eye cannot see. They have five eyes- 3 small, single lens eyes that help navigate and orient them in the landscape, and 2 large, compound eyes comprised of thousands of lenses. It allows them to see colors from orange-yellow to ultraviolet.  Bees cannot see red. Therefore, flowers that depend on bees as pollinators are usually yellow, purple, or blue. Additionally, bee pollinated flowers often have special UV patterns that are vividly apparent to bees, but that humans can’t detect. https://www.blm.gov/or/resources/recreation/tablerock/files/pollination_partners.pdf 
  1. Buzz– By shivering its thoracic muscles (the muscles controlling their wings), the bumble bee can keep warm enough (30 C/ 86 F) to forage in cool or wet conditions. This means they can forage longer in spring and fall than other pollinators. Bumble bees also use buzzing to actually loosen and attract pollen from a flower.  This is called “buzz pollination.”  Some flowering plants hold their pollen tightly in their anthers (the part of the plant that produces pollen.  See September’s blog post.) Bumble bees can shiver, or contract, their thoracic muscles while holding on to the anther with their legs and mouth.  This shakes the pollen out and it lands on the hairy body of the bee.  The bee will “comb” lots of that pollen into a sac on her legs to bring back to the nest, but some will remain and will fall off on the next flower.  Bumble bees are designed for pollination!  (https://www.xerces.org/publications/identification-and-monitoring-guides/bumble-bees-of-eastern-united-states)

Watch this short video on buzz pollination:

https://www.youtube.com/watch?v=J7q9Kn1rhRc

So, right here in our community, super heroes are at work pollinating our native plants, shrubs, trees, and food crops.  There are 14 species of bumble bee here in Pennsylvania (https://extension.psu.edu/common-social-bees-and-wasps-of-pennsylvania-behavior-lifecycle-and-management) and 49 in the United States. They can be separated into 3 different classes related to tongue length- short, medium, and long.  The different length tongues allow the bees to forage on flowers of different shapes and sizes. (https://www.fs.usda.gov/wildflowers/pollinators/pollinator-of-the-month/bumblebees.shtml) 

New scientific research is discovering that tongues of bees are getting shorter to be able to cope with fewer flower species surviving climate change. (smithsonianmag.com, science.org “Warming World has Shrunk Bee tongues.” washingtonpost.com)  

Our bumble bees are so amazing, yet we are losing them.  According to the Penn State Extension website, numbers of bumble bees in Pennsylvania are in steep decline.  “An endangered species, the rusty patched bumble bee (Bombus affinis), was last recorded in 2006. Other species of bumble bees that are currently threatened or declining are the American bumble bee (Bombus pensylvanicus) and yellow bumble bee (Bombus fervidus), both last recorded in 2018, and the yellow-banded bumble bee (Bombus terricola) most recently detected in 2009.”  Reasons for the decline include pesticide use, habitat loss and fragmentation, pathogen spillover from managed bees, and climate change.  

https://extension.psu.edu/bees-in-pennsylvania-diversity-ecology-and-importance

You can help!  Plant several species of native flowering plants from spring blooming to fall blooming.  Make sure your flowers were not grown with neonicitinoid pesticides (Ask your nursery.) Eliminate pesticide use in your yard.  Allow ground nesting sites for bumble bees.  

Click on the link to put your name in a drawing for a picture book on bees:   https://forms.gle/4b9jQkvZkj9T3t2n6

Next month we will highlight the Red Admiral butterfly!  Did you know that the Red Admiral flies during the day AND at night?  (Bumble bees can only fly during the day.)

For further reading on bumble bees:

https://xerces.org/publications/identification-and-monitoring-guides/bumble-bees-of-eastern-united-states

https://extension.psu.edu/conserving-wild-bees-in-pennsylvania

https://extension.psu.edu/what-can-we-do-to-encourage-native-bees

https://www.washingtonpost.com/news/energy-environment/wp/2015/09/24/climate-change-is-having-a-surprising-effect-on-bumble-bees-their-tongues-are-shrinking/

https://www.smithsonianmag.com/science-nature/bee-tongues-are-getting-shorter-temperatures-warm-180956738/

https://www.science.org/content/article/warming-world-has-shrunk-bee-tongues

https://www.biorxiv.org/content/10.1101/2021.03.17.435598v3.full

https://www.pbs.org/wnet/nature/blog/bumblebee-fact-sheet/

https://www.livescience.com/american-bumblebee-endangered

https://www.usgs.gov/centers/eesc/quick-background-mid-atlantic-regions-native-bees

https://www.bumblebeeconservation.org/bee-faqs/buzz-pollination

For tips on how to create nesting places for pollinators:

https://xerces.org/publications/fact-sheets/nesting-overwintering-habitat

https://xerces.org/leave-the-leaves