replacing old equipment

 

 

I prepared new deep boxes to replace boxes in use since 2007.  To assist bees in finding their hive, I added a unique painted pattern to the front of the box using an adhesive stencil.    Jürgen Tautz discussed hive marking in The Buzz about Bees - unique pattern are a better bee orientation aid than a unique color.

To enhance the propolis envelope, I made parallel 1/8 inch (3.2 mm) wide shallow grooves seen in the photo.  Last year, I showed that shallow grooves in medium box walls improved the propolis envelope.  This year, I made similar grooves with these deep boxes.  On old 2007 boxes, propolis was concentrated on frame rests, other right angle corners and box abutments - only a thin layer of propolis was found on its smooth box walls.

enhancing propolis envelope

I described the honey bee health benefits of a propolis envelope in an earlier post. 

• lowered immune response expression
• less bacterial growth in brood food
• lower number of chalk brood mummies
• reduced severity of American Foulbrood

In March of this year, I added a box where I created side-by-side patches of shallow grooves with a dremel tool and router bit. After honey harvesting, I removed this box and analyzed the interior wall for propolis.  I cropped the photo so exactly 11 grooves in each patch are included in the comparison of: 

• 1/4 inch (6.4 mm) wide shallow grooves (on the left)
• no grooves (seen between two patches)
  
• 1/8 inch (3.2 mm) wide shallow grooves (on the right)

In the first photo, propolis appears as a red film which is distributed everywhere, but groove edges have a thicker red film. In the second photo, I used SimpleCV to mask out areas of thin propolis film.   In the third photo, I used SimpleCV to draw regions of thick propolis and compared 3 regions:

• 61.5% of thick propolis area was associated with 1/4 inch (6.4 mm) wide shallow grooves (on the left)
• 0.5% of thick propolis area was associated with no grooves (seen between two patches) - look at the bottom of the photos for thick propolis in the no groove region
  
• 38.0% of thick propolis area was associated with 1/8 inch (3.2 mm) wide shallow grooves (on the right)

I'm not suggesting 1/4 inch wide shallow grooves is the best option.  More narrow 1/8 inch grooves pack into the same length of box wall than wider 1/4 inch grooves.   There's no significant propolis advantage of either groove width except to say grooves outperform doing nothing with regards to enhancing a propolis envelope. 

an experiment, enhancing the propolis envelope

Seeley's new book, The Lives of Bees, describes propolis research by Marla Spivak and others at the University of Minnesota.   In the wild, honey bees coat their tree cavity surfaces with propolis - with an especially thick layer of propolis at their nest entrance. In experiments with man-made 5 frame hives, hives with a propolis envelope have better health:

• lowered immune response expression
• less bacterial growth in brood food
• lower number of chalk brood mummies
• reduced severity of American Foulbrood

Having seen the experiment where plastic propolis trap material (with 7 mm gaps) is stapled to hive box walls, I'm inspired to modify my own hive.   Shown are medium box walls where bees added a thin layer of red propolis from previous years.  I created side-by-side patches of shallow 1/8 inch (3.2 mm) and 1/4 inch (6.4 mm) gaps to box walls using a Dremel tool.   Whether bees create a thicker layer of propolis is left to be seen during this 2020 season - stay tuned.