Why Jaws of Worker Honeybees Differ From Queen Bees

First off, the “jaws” of honeybees are really called mandibles.  “Mandibles” is a lot to get in a header, and they do act as jaws.  The mandibles open side to side rather than up and down like our jaws.  The queen’s mandibles and the drones’ mandibles are pretty similar, to each other and other arthropods (a phylum that includes insects, spiders, crustaceans).

However the mandibles of worker honeybees are a little bit different.

(An aside : this link will explain how Phylum fits with other biological classifications)

The Basic Difference:

Queens and drones have pointed mandibles that have notches at the end.  Worker bees have smooth spoon-shaped mandibles.

Why The Difference:

Honeybees are in the order of Hymenoptera (which is under the arthropod phylum), which includes bees, wasps, ants, sawflies and more.  For the majority of these insects, mandibles are for cutting and biting.  Honeybee queens and drones follow this traditional pattern.

Worker bees don’t need to cut and bite as much as they need to mold wax.  So they evolved a different set of mandibles.  They still open from side to side, but their smooth spoon-tipped mandibles are perfect for molding wax into shape.  Amazingly (to me) these smooth jaws can still cut away wood, uncap worker and drone cells, and give a pretty good bite.

Interestingly I searched all over the web and in books for this information.  Current sources kept saying queens and workers have different mandibles.  It was only when I came across “The Anatomy of the Honey Bee”,    written in 1910 (!),  by Robert E. Snodgrass , that I found why queens and workers have different mandibles..  Sometimes you just can’t beat those older sources.

Of Queens And Drones:

Queens have bigger mandibles than drones, who have the smallest mandibles in the hive.   Both queens and drones have a notch just below the tip of the mandible just like most bees, ants, wasps, and other insects of the hymenoptera order.

It seems that queens use these notches for cutting their way out of their very dense queen cells.  I figure (this is a guess) that they come in pretty handy in a queen versus queen fight as well.  Plus the queens and drones have no need to push and mold wax, so no need for spoon-shaped mandibles.

Drones probably have notches because most insects in their order have notched mandibles…no evolutionary need to change.

Other Interesting Mandible Stuff:

Mandibular Pheromone Glands

The queen has these, workers do not.  These glands produce the pheromone that tells the hive : we’ve got a good (or failing) queen.  The same pheromone attracts drones for mating.  Once mated, queen steps up production of this pheromone, which takes us back to “we have a good queen here”.   All that and so much more, which is for another blog post.

For this post, I was simply fixated on the question of “why are a queen’s mandibles notched, and a workers are not”.

Why the Fixation on Honeybees’ Mandibles Physical Design:

Beekeeper Pat Ray and some of his queen cells

Pat holding queen cells he grafted

This blog topic was inspired by a really wonderful presentation by beekeeper Pat Ray  at the Skagit Valley Beekeeper’s  meeting last week. Pat’s presentation covered both the biology of the honeybee and “a year in the bee yard”.  Brilliant, talented beekeeper Jody Gerts (scroll down to find her), gave Pat a number of PowerPoint images to use.  When he got to the one about how queens differ from workers, there was this line about queen mandibles being notched while workers are smooth.

Pat admitted he didn’t know what that was about.  It doesn’t affect beekeeping, but it got us wondering.

A Word about Pat Ray

A beekeeper and his dog

Pat and his dog

Pat’s a 4th generation beekeeper (that’s his “pup” who is a constant companion in the beeyards) with whom I had the great pleasure to work with on and off for two years.  He knowledge about beekeeping is amazing, and, better yet, he’s very willing to share that knowledge with beekeepers new to the world of bees or folks who have years of experience under their bee suits.  I could go on about all I learned from him, but I think the most telling moment was when I turned up to help him and Bruce Bowen  make splits.  Bruce had a partial suit on.  Pat was standing there in shirtsleeves, no veil.  Me?  I was in a full bee suit.  “You’re going to laugh,” I said a bit self-consciously as I put on my suit.  “No,” Pat said.  “When working bees you’ve got to wear whatever makes you comfortable. If you’re comfortable, the bees are comfortable.”   Care for others and for the bees – that says a lot about Pat Ray.

What’s Happening Right Now With The Bees:

They are in cluster.  Periodically a few stick their heads out and say “geeze it’s cold out there” and go back in).  Which means I get to spend hours at the library (the only WiFi location in this area) trying to sort out a mess, which occurred when I began to switch from one web host to another.  The PacificNorthwestHoney.com website went down. And I don’t really talk webtech.  So you can see why I’d far rather talk about the interesting evolutionary adaptation of worker bees’ mandibles.

(Another aside: if you’ve not visited Eric Tourneret’s Photography site, you are missing really amazing images)

That’s the news from Brookfield Farm Bees And Honey, in Maple Falls Washington what’s happening in your area bee-wise?

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About brookfieldfarmhoney

Brookfield Farm, a small off-grid apiary in Maple Falls, WA focuses on the beauty and bounties of Washington’s wilderness. I sell honey from our bees, whose naturally-treated, antibiotic-free hives are home to bees who fly Washington’s mountains and farmlands. Herbal salves and lip balms from Brookfield beeswax. Delicately infused honeys and vinegars. Varietal honeys from independent Washington beekeepers. Karen Edmundson Bean: beekeeper, photographer. Her love of the wilderness inspires her to discover new ways of bringing the wonders of nature to others. Brookfield Farm : the tastes, textures, sounds, and images of nature.
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7 Responses to Why Jaws of Worker Honeybees Differ From Queen Bees

  1. Emily Heath says:

    Fascinating post, thank you! This doesn’t get talked about much in bee books.

  2. ‘Whats happening in your area be wise’ you say? Well, here in southeast Idaho (Idaho Falls) the temperature has been in the minus side at night, as muck as 16 below, and reaching in to the lower teen during the day, unseasonably below normal. One day last week it did warm up to 38 degrees (briefly) and so I checked on the ‘girls’ to see what was happening. (being a new beekeeper, I have been worried about them and have done what I could to over winter them). I do hope they make it to spring as I have many fruit trees the can forage. Living in town, there are many other plants that are available to them.
    Thank you for writing this blog. I have been enjoying it and plan to be a regular reader.

    • Your area makes ours sound down-right tropical. I would think your bees would be in a solid cluster, and hopefully, no where near the top of the hive. What did you find? I’m glad you’ve enjoyed reading the blog.

  3. willowcreekhoney says:

    Interesting! Today, Jan. 20th, even at 14 degree F temperatures, The ‘girls’ were out for a flight. I assume a cleansing flight because there is bee poop all over the ground. Well, it’s just too cold for that and there are dead bees all over within 10 ft of the hive. I am hoping this is O.K. Not really much I can do about it any way. Bees are still ‘buzzing’ in the hive. Thought you would find this interesting.

    • That’s fascinating that they would come out at 14F! What kind of bees do you have?

      • willowcreekhoney says:

        They are Carniolian. I suspect that while the sun was shining, that perhaps they thought in was warmer than it was. Plus the fact they had been cooped up for over 2 weeks they really had to ‘go’. Today the weather broke reaching the 32 mark. Much more seasonable. I figure that if bees survive in Minnesota, they should survive here. (It is much warmer than weeks of 30+ below. I know because I used to live in eastern Montana. Gets real cold there too.)

        • I really like NWCarniolans too (and Russians, but Russians can be a bit touchy) – that makes sense that your bees would come out on a sunny, cold day.  They are “built” for cold weather: small winter clusters, queens cease laying when stores/forage get low… And they fly in temperatures that leave Italians dreaming of warmer climates – if bees did dream…. 

          On Thu, 24 Jan 2013 02:39:46 +0000, “Brookfield Farm Bees & Honey Blog”

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