Saturday, January 18, 2020

Native Bees

Osmia aglaia- a metalic carpenter bee
Looking for color on a dreary January day?  I would suggest a digital stroll through the USGS Native Bee Inventory and Monitoring Lab.  There is no charge and you won't even have to leave your screen.  I was introduced to this by Dr. Chris Barnhart who sent me a poster with 25 facts about native bees.

The European honeybee, Apis mellifera, gets all the press with its role in pollinating agricultural crops and of course the commercial production of honey.  Say "bees" and we immediately think of colony collapse disorder.  Bee keeping is also a major hobby.  After spreading across Europe and Africa 2-3 million years ago with the Pleistocene warming, they arrived in North America with the European settlers in the early 1600's.

The spread of A. Mellifera has been wonderful but it has caused us to overlook and undervalue all the 4,000 native bee species!  How does that compare to other species in North America?
  • 4x more than bird species
  • 6x more than butterflies
  • 10x more than mammals
Perdita portalis  - USGS Bee Inventory
There are currently 634 species in the genus PerditaSome Perdita sp. found in the southwest measure 0.1 inch, smaller than Washington's nose on a quarter.   Many are brightly colored with yellow and white and iridescent metallic shades.  Most collect pollen from only a few specific plants.  All Perdita cannot sting.

Eastern carpenter bee - Xylocopa micans

At the other end of the spectrum there are giant carpenter bees, Xylocopa, which are over an inch long. The Eastern carpenter bee pictured here (X. micans) is a good neighbor, sticking mostly to the wood found in nature including hollow plant stems.  You can provide them shelter with a variety of native bee houses which will also attract potter bees that seal up the cracks and hollows of their individual nests with mud mortar.

The common Eastern carpenter bee, X. virginica is an exception in the carpenter and potter bee families.  It has developed too much familiarity with civilization and sometimes bores into wood of all kinds such as trees, porches, fences, decks, and (Boo!) cedar siding of our houses.  Painting or staining wood siding and repairing cracks discourages them.

Here are some of the facts that you can see in the 25 Slides in this USGA Presentation.
  • Native bees don't make honey.....Boooo!
  • Many cannot sting you.....Yeah!
  • Carpenter bees have the largest insect eggs.
  • Vast majority nest in the ground.
  • Bees are vegetarian wasps!
  • 20% of species don't gather pollen - the cuckoo bees sneak their eggs into other bees' nests and let them raise their young!
  • Only 1% of our bees are non-native.
  • Males do not help in raising their young.  (My wife says, "So what is new about that?)
  • Over 35% collect pollen in only one plant species.
  • Most nest only a few meters from their flowers.
  • Many native bees pollinate our fruits and vegetables as well as all the other plants ignored by A. mellifera.
None of this is to demean the role of our beloved A. Mellifera, European honeybee.  We just need to recognize the role that all insects have in our world and the need to maintain native habitat to preserve these species.  All native lives matter.

To dive further into native bees I would suggest Bees in Your Backyard by Wilson and Carril.  
Want to "grow" some native bees in your yard?  Try 100 Plants to Feed the Bees.