Cellophane Bee

2009 May 9

Wednesday afternoon was warm and sunny, for just about the first time since last fall. S_ was working out in the yard, and called me outside, saying “There’s a swarm of bees in the driveway!” And so there was. There were about 100 of these guys, circling around the light-colored, sandy parts of the driveway and flying at an altitude of about 1 to 4 inches. I tried photographing them as they flew, but they were too quick for me. It took quite a few tries, but I eventually caught one in a jar:


While trying to catch one, I noticed an interesting thing: every now and then slightly larger, slightly yellower bees would fly up, land on the ground, and immediately be pounced on by one or more of the ones flying in circles. They would wrestle for a few seconds, and then the larger one would fly off. The smaller ones would then continue circling until another larger one came by.

I wasn’t able to catch one of the bigger ones, but I’m pretty sure that what was going on was that our driveway had turned into a mating congregation area. The smaller ones patrolling the area were the males, and the larger ones were the females. I think they were using the light-colored soil as a landmark so that the females would know where to find the males, and the males were just hanging around waiting for them to show up.

One of the features of bees (as opposed to wasps) is that bees are pretty fuzzy. This one had white fuzz covering his entire thorax, and even going over his head.



There are dozens of species of solitary bee like this one, but Eric Eaton was able to identify it as one of the cellophane bees, genus Colletes, based on the wing vein pattern. The name “cellophane bee” comes from the ability of the females to secrete a waterproof film (that looks similar to cellophane)[1] that they use to line their egg burrows. Each female bee digs her own burrow with individual cells, and stocks the burrows with pollen and nectar, lays eggs, and seals them up. The larvae then grow up during the rest of the summer, overwinter as pupae, and pop out early in the spring.

While I was out trying to catch a specimen, Sam kept calling out “Careful, Dad! Don’t get stung!” There was not much possibilty of that, though, because most of the bees were patrolling males, and male bees don’t have stingers (stingers are modified ovipositors, so only the females have them). It was slightly possible to get stung by one of the females, but they weren’t all that numerous, and like other solitary bees and wasps they aren’t inclined to sting unless their lives are at immediate risk.

[1] If Wikipedia is to be believed, the film is actually polyester. This sounds fishy to me, I wasn’t aware that polyester could be produced biologically, and the few other sites that I’m seeing that quote this little factoid obviously got it from the wikipedia page. Some type of cellophane does sound intrinsically more likely, seeing as how cellophane is derived from cellulose, and the bees would be able to get cellulose easily enough. I’m not sure where they would get the dimethyl terephthalate and ethylene glycol to make polyester, though.

7 Responses
  1. May 10, 2009

    I hear that bees are very industrious. Maybe they used that industry to manufacture the polyester.


    I didn’t know that about the stingers. The hair on the bee makes it look like a stereotypical Arkansas grandpa.

    Another marvelous post and set of photos. Bravo!

  2. May 10, 2009

    Great photos and great information!

  3. May 11, 2009

    Thanks! I suppose if I want to answer the cellophane/polyester question conclusively, I’ll need to rummage about in the scientific literature and see if anyone published an actual chemical analysis of the film the bees secrete.

  4. May 11, 2009

    Hey, that was easy! Here we go:
    (From “Science”, 27 April 1979: Vol. 204. no. 4391, pp. 415 – 417)

    Natural Polyesters: Dufour’s Gland Macrocyclic Lactones Form Brood Cell Laminesters in Colletes Bees

    Bees in the genus Colletes make their brood cells in the ground and coat them with a highly resistant, waterproof, transparent membrane. This membrane is a polyester constructed mainly from 18-hydroxyoctadecanoic acid and 20-hydroxy-eicosanoic acid, which are stored as their corresponding lactones in the Dufour’s gland of the bee. When lining the cells, the bee secretes its glandular content, and the membrane is apparently a product of polycondensation reaction of its contents. This appears to be the first report of a naturally occurring linear polyester. The term laminester (lamina sime layer + ester) for this class of compounds is proposed.

    So! On the one hand, it really is polyester (although using a different chemistry than what we humans use), so I guess Wikipedia was right. On the other hand, this sounds like the first case where an organism was found to secrete a polyester film, so I was justified in being a bit sceptical of it all.

  5. May 16, 2009

    Yes, but is it stain resistant? If the bees spill mustard in their hive, will the stains come out?

  6. May 16, 2009

    Yes, but is it stain resistant? If the bees spill mustard in their hive, will the stains come out?

    And do the bees ever use this ability to make tiny little leisure suits?

    If not, they should.

  7. Dani permalink
    July 17, 2016

    Thanks for the great information. I am sad that the bee died though.

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