Biochemical Soul Musings on Nature, Science, Evolution, Biology, and Education

The Carpenter Bee and Her Mate

Today I witnessed (and was an integral part of) one of the strangest and coolest insect-related events I've been privy to.

My wife and I are trying to get our home fixed up to be put on the market.  One of the things we will be doing is repainting our front porch. Unfortunately, our porch is riddled with holes under the edge (that are invisible because of their positions). The holes themselves aren't a major problem, though appraisers certainly take note of them.

You see, the holes are caused by the Eastern Carpenter Bee (Xylocopa virginica). We live in the woods and hundreds of them buzz around me daily. They're actually pretty cute and are quite important pollinators. The trouble comes when woodpeckers, mostly Red-bellied Woodpecker (Melanerpes carolinus), take note of them and destroy the wood to get at the tasty bees and their offspring within the bees' tunnels.

So this morning, after watching a bee exit the hole (I initially thought it was a male but now I know it was a female), I promptly sealed the hole with putty thinking the problem was solved.  I felt a little bit bad that all the bee's excavation work had been for nothing - but what could I do? Holes in my house structure are not a good thing.

Two hours passed.

I stepped out onto my porch and saw the bee again. This time however, she was frantically chewing at the wood above the bore tunnel (the entrances are always on the underside of the wood). In fact, she had already dug a hole large enough to stick her head through.

Then I noticed that there was another bee inside the burrow. I could see his little head staring upwards from the new hole (I now know that males have a characteristic white face).

I had sealed in the bee's mate!!

The bee kept sticking her head into the hole, followed by a strange buzzy chatter between the two bees. She kept trying to climb in but she hadn't made the hole big enough yet.

Eastern Carpenter Bee attempting a daring rescue

"Don't worry, Bjorn! I'll get you out!"

You must check out the video.

At this point I thought "Well, I sealed in her man, she thwarted my big-brained attempt at sealing the wood, and it's clear that she desperately wants back in - I might as well help a bee out."

So I grabbed my pliers, shooed her away from the hole, and widened it enough for her to fit through.  She immediately went straight inside, after which there was much buzzy rejoicing (at least that's my own anthropomorphic imagining of what all the buzzing meant).

I ripped the hole wider with pliers and in she went.

I didn't really expect a rescue with the both of them exiting into the sunset to find a new home. I fully expected them to resume normal life (though it was still a rescue). In fact, I decided that since I don't really need to seal the hole right now, and since the bee had shown an amazing dedication to her mate (or more likely, her brood), I'd let them get through their rites of spring.

My wife witnessed the whole thing and felt bad for the bee as well, so she was happy to let them keep their home a little while longer.

But as I said, I really don't know much about carpenter bees. So a little research was in order.  I found two excellent websites on carpenter bee life cycles and habits: One at Penn State and one at Ohio State. From these sites I learned a few details that made my plan a bit moot.

About the Eastern Carpenter Bee

First of all, unlike social bees such as bumblebees and honeybees, carpenter bees are much less social. A male and female pair up, the female excavates the burrow, and the male hovers around the burrow defending their territory.

The defense of the home is actually quite entertaining to watch. Every few minutes one (or sometimes several) bees will come near the nest. The diligent male immediately locks into a hurtling, writhing ball with the other males while making a loud ruckus, and chases them away.

This explains why I had only seen the one bee actually enter the nest. The female remains mostly inside the nest, though I must have happened to catch them while he was in and she was out.

Second, after the female excavates the entrance, she makes a 90 degree turn and continues the tunnel along the wood grain. After completing her tunnel, she deposits eggs (along with a food ball) one-by-one inside the burrow, sealing each "brood chamber"  behind her. The chambers are collectively termed a "gallery."

Unfortunately, much like other insects, cephalopods, and many other animals, the female dies shortly after laying her eggs. So she is a goner no matter what I do.

The eggs that she lays then take about seven weeks to reach adulthood. However, they don't emerge from the burrow until August! They collect pollen and store it inside the galleries, and hibernate inside throughout the winter. In the spring, they emerge again to begin their own life as mating adult bees.

One thing I am certain of is that I can't wait until August to seal the holes - and even if I did I would probably just be dooming the new adults to a cold wintry death.  So really, my entire altruistic idea is a moot point. I'm not really sure what I'm gonna do about them now.

Obviously, they are "just" insects. I'm certainly no St. Francis of Assissi¹ or Ko Hung². That being said, I don't generally enjoy killing anything unnecessarily. As I said before, we are surrounded by carpenter bees - our woods provide ample habitat - so I certainly won't be hurting the population.

Most people just shoot pesticides into the nests. I, however, refuse to use pesticides on my property (partly because we are on well water). I guess I could just try to seal it again, though I imagine they will find a way back in (or out).

What do you think I should do?

A couple of other points

Male carpenter bees cannot sting (males are distinguished by a white face - see image below).

Females can sting (but you basically have to handle them before they will).

Carpenter bees at my house buzz me constantly, hover in my face, land on me - but I have never once seen one act aggressive, even if I bat them to get out of my face. They are mainly just curious and very gentle creatures.

Male:

Eastern carpenter bee male showing large eyes, white face and mouthparts (image via Wikipedia)

Footnotes

1. "Not to hurt our humble brethren (the animals) is our first duty to them, but to stop there is not enough. We have a higher mission--to be of service to them whenever they require it... If you have men who will exclude any of God's creatures from the shelter of compassion and pity, you will have men who will deal likewise with their fellow men." - St. Francis of Assissi
2. "Respect the old and cherish the young. Even insects, grass and trees you must not hurt”. T’ai-shang kan-ying p’ien, a Confucian-Taoist treatise. Attributed to Ko Hung"