Thursday, September 6, 2018

Bumbling Around

Bombus Sonorus aka Sonoran Bumblebee (gender unk.)

Bumbling Around In The Yarden

I must lead an insect sheltered life, not being aware that we had bumblebees in our area.  For some reason, I thought they were exclusive to colder climates.  However, I was recently educated in the possibility of two bumblebees that may be foraging in our yarden.  The choices were Bombus Morrison or Bombus Sonorus.  Bombus Sonorus is currently under dispute as being under the American Bumblebee umbrella Bombus pensylvanicus or an independent subspecies.  In any case, either bumblebee species is over 50% decline during the last 10 years.

Based on the banding, we have Bombus Sonorus.

Why Haven't I Seen These Before?
Bombus Sonorus aka Sonoran
Bumblebee (gender unk.)


Given the size of these bees, it is possible they were mistaken as carpenter bees (we have a lot of those), but never really noticed how fuzzy the butt was before.  Fuzzy butts are bumblebees and smooth butts are the carpenter bees. 

Since documenting the activities around the luffa gourds, more attention is being given to what is visiting these days and the Sonoran bumblebee is now on the list of luffa fauna.  Following achievement of awareness, the next question on my list is how can I attract more of these and what do they need for more stable sustenance throughout the year.

These questions are answered from understanding the life cycle of the Sonoran Bumblebee.

Bombus Sonorus aka Sonoran
Bumblebee (gender unk.)

Sonoran Bumblebee Life Cycle


The bees start emerging from the burrows during spring.  Bumblebees are excellent pollinators of tomatoes, eggplants, blueberries and cranberries as they sonicate (vibrate) the flowers to expel pollen and distribute from flower to flower. You know you have sonicating bees when you have high yields of tomatoes, eggplants, cranberries and/or blueberries.

The population of bumblebees are most visible during August.  Visibility slightly tapers off through the fall months due to the males breeding and dying off in a few weeks and the worker females not living much longer.  A strong colony will produce a large number of queens to perpetuate the species in fall.

Queen Sonoran Bumblebees make nests out of old rodent holes.  The belief is the insulated hairs from the rodents make for a nice, warm and dry environment needed to raise a 50-500 cell brood. (Lucky us, we have hybrid ground/roof rats around here and may actually have made space for them when getting rid of the rats).  Queens enter diapause (hibernation) in late fall and start producing young in spring after awakening. 


Is It A Boy Or A Girl?
Bombus Sonorus aka Sonoran
Bumblebee (gender unk.)

It is possible the photos we have are of a male.  Males do not have pollen collecting hairs on their hind legs and have longer antennae (however the antennae length is relative and we have nothing for comps).  

The legs don't seem to be saddled with pollen, so could be male.  We really don't know much about these yet.