We’ve got lots of carpenter bees — visiting the Cleveland Sage in our front yard, and now laying eggs above. About a year ago I saw sawdust below an old parrot perch sitting outside and over the next few months got to witness an adult carpenter bee drilling into the wood prior to laying eggs. Then I even caught a newbie below one of the holes as it adjusted to making its way into the natural world. We have other old wood posts where they appear to have nested – and I was glad to offer them nesting sites on our property. They are also very active in pollinating our flowers.
However, you hear so many negative things about them so I asked a couple bee experts — Robbin Thorp, Professor Emeritus from UC-Davis and Professor Keith Delaplane from U. of Georgia — for their views.
The takeaway: While the eastern carpenter bees are more problematic, the western ones are not and have a role as pollinators.
First, for background, large carpenter bees (genus Xylocopa) are wood-nesting generalist pollinators who forage wide range of food plants over a long season of activity, and tolerate high temperatures. More info:
3 California Species: According to Dr. Thorpe, the smallest is Xylocopa tabaniformis opifex, sometimes called the Foothill Carpenter Bee; the two largest are X. varipincta, the Valley Carpenter Bee; and X. californica, the California Carpenter Bee (which it appears we have). See photos below or BugGuide.net page for more photos and info.
Not Pests: Thorp says that for the most part western carpenter bees are not “pests” but he acknowledges that each person has their own definition of what is a pest.
Where they nest: X. tabaniformis nests primarily in untreated redwood lumber used in fences, arbors, patio furniture. “They have become very common in residential areas, since we provide them with so many home sites. As long as the redwood is not a supporting timber, the bees should not be a problem,” says Thorp.
X. varipuncta nests in dead limbs of trees rather than human structures. “The male of the species is a buff golden color with green eyes. We refer to it as the “teddy bear” bee.”
X. californica occurs primarily in the mountain foothill areas of northern and southern CA. It has bluish metalic tints to its body color and nests primarily in pithy stalks of yucca, sotol, and agave.
For more info and photos: See articles below by the UC Davis Department of Entomology, Communications Specialist, Kathy Keatly Garvey:
X. tabaniformis orpifex: GardenWeb article and blog article and
X. varipuncta or Valley Carpenter Bee: MasterGardener Article
“In truth I find them interesting and amusing, and our urban entomologists consider them more a nuisance…. Dr. Keith Delaplane, U of Georgia entomologist
Dr. Delaplane is familiar with the eastern carpenter bee – Xylocopa virginica – which is considered a pest because they bore conspicuous holes in carports and siding. They can alarm people with their aggressive territorial flight behavior but added, “In truth I find them interesting and amusing, and our urban entomologists consider them more a nuisance than a problem on par, say, with termites. In general their structural damage is comparatively minor. So, in my book a relatively minor pest human-wise,” he says.
While many varieties of carpenter bees are helpful pollinators, Delaplane said the eastern variety are notorious nectar thieves, piercing the flower laterally to suck out the nectar and bypassing pollination. “Here in Georgia the holes they make in blueberry flowers then incites honey bees to visit the holes, thus becoming secondary thieves. A student’s research (Nectar Robbing Carpenter Bees…) showed that this secondary robbery costs the plant the seed set but not necessarily fruit set (one would think the two go together, but not necessarily).”
Another research paper on pollination Large Carpenter Bees as Agriculture Pollinators
Eastern resources: http://www.ent.uga.edu/bees
Linda! Thank you for introducing me to the carpenter bee. I always thought any bee that wasn’t a wasp or a honey bee was a bumble bee.
good! I wasn’t sure either when I first saw them. Also, the males of some carpenter bees are fuzzy and tan so can look like bumblebees….
I have an old stump out back of my house in Los Angeles, where carpenter bees live. I often find some dead on the ground around the stump. I rescued one gold male that wasn’t completely dead, but had gotten soaked from my watering nearby. I put him in the sun to dry out on my patio table. Eventually he took off. But why are there so many dead adults around the stump? Do you know?
Thanks for your attention,
Hi Lindy, I’ve queried a couple biology experts and got one reply so far saying “there was no reason for them to die en masse like that it should be some kind of insecticide that they are getting into or being exposed to.” Perhaps neighbors are using insecticide?
Another reply on above q by UC Riverside’s Sean Prager (who has studied carpenter bees. A lek is a mating area where males compete for females): “It is difficult to know for sure without seeing the adults, and without knowing for sure which species. I assume that these are Xylocopa varipuncta since they are more commonly in cities and have golden males. There are a couple of possible reasons for the dead adults. If they are mostly males, it is likely they are losers from mating. This species has a dispersed lek mating system. And so, you will get a lot of males around a seemingly worthless landmark. So, if it is mostly males, these may have been those that lost the confrontations. Usually these leks occur where there is no real resource (like a nest or flowers). If there are also females, this could be from a couple of things. Although, females of that species are not well studied and this is a little guess. In many carpenter bees, females try to get through multiple seasons and then die in the nest. If another female tries to use that nest, either because she inherited it or found it unused, then she will
Today we noticed the Valley Carpenter Bees nesting in our half dead Weeping Willow tree about 30 feet from our house. Lots of fuzzy golden males as well as the black ones…..they are huge compared to our local honey bees….which we don’t have a lot of.
My husband is allergic to bee stings. Should he be worried about them swarming or stinging without provocation?
How do we get them to relocate? Will they eventually move on…….? It seems they have found the perfect nesting site, but a little close for comfort.
I’m allergic to bee stings too and have never had trouble with any bees. Carpenter bees may nest together but they’re solitary – so won’t swarm. I would enjoy them- they’ll move on…don’t know if they reuse the nest site, it would be a new population so perhaps not…
As weird as it may sound Ive had several interactions with these bees that seemed that they were as curious about me as i was about them. They would land relatively close, facing me and seemed to stare, take off, return and stare again, all very none threatening. Has anyone had similar experiences or can tell me about there intelligence?
Hi Carmen, thx for your comment. I’ve found the males very skittish during mating season but other times have had similar behavior in carpenter bees in not being afraid of me at all.
Hi I live in the uk…in the north east dales area…I found what I thought was a black bee crawling on my living room carpet….I rescued it and took it outside where it jumped on a dandelion…I put sugared water nearby incase it was exhausted…but on googling I’m still not sure but think it’s a carpenter bee…are these rare in my part of the world? I’ve never seen one before.
Hi Chris, according to wikipedia! there are carpenter bees world-wide, tho I can’t say for sure what’s in the UK. But if the US has thousands of species of native bees, you have a large variety too.
Do they sting you?
No they’re calm bees and don’t have stingers, and are not known to bite. Here’s one answer from an entomologist – http://www.askabiologist.org.uk/answers/viewtopic.php?id=5300
I was staining my fence this past week and sat on a bucket with so many of these carpenter bees buzzing around me. I stopped and got my camera, sat down and started shooting many pictures. They seem to never stop but only a second or so. I’ve had them hover facing me and then charge. I’ve felt their wind from their wings when they get close. I did manage to get some beautiful pictures of them. I don’t mind a few holes just to be able to observe these large bees up close.
Hi Paul, how great – they do buzz around so quickly – they must have a short mating season…? If you want to send any photos I’ll post them on this post with your name… thx, Linda
We have a nest in a log with the usual pile of saw dust below it. Now there are small dark (black?) rod like deposits on top of the saw dust…perhaps 10 mm long and 2 mm wide, very small…what might they be?
Don’t know… haven’t seen those unless it’s maybe poop?! Xerces Society is a great organization and website on native bees/wasps — https://xerces.org/pollinator-conservation/native-bees/#
I live in the San Francisco bay area and this is the second year that a golden carpenter bee has visited my bare Gravenstein Apple tree. It hangs out and never lands. Last year I got a couple of pics, but there’s too much folliage for me to get close this year. I was thrilled because it’s only one bee, not a pair. Is it possible that they come because they remember the place? There are no blossoms or anything to feed on, why would it return?
Don’t know but I read where males live a year but females can live longer – was it a female? There’s likely good habitat nearby!
I have been seeing a huge golden bee slowly flying by, several times now. When I read about these “teddy bear male carpenter bees” I only find references in California. Are they here in cape cod, Massachusetts? Thank you.Vicki Solomon
Hi Vicki – could they be a type of bumblebee – this website — https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/bumblebees.shtml talks about 49 species in the U.S.? I don’t really know the range of carpenter bees but I sometimes I get the two confused. Thanks for writing and good luck!
Hi I live in California and we have a very cute carpenter bee living in the wood we use as target practice for throwing knives and axes. We’ve decided to let her stay this year however we intend to seal up the hole after to detere her from coming back next year. as we have decided not to throw knives/ axes while shes still in there because we don’t want to accidentally hurt her. My question is how do we know when all the babies have left so we don’t seal them in on accident?
sorry I missed your q – I’ll also email you – I have read where a carpenter bee’s lifecycle from egg to adult is 7 weeks while another site from California – http://ipm.ucanr.edu/PMG/PESTNOTES/pn7417.html – says 3 months and they emerge in late summer, so considerably longer. You are being very kind to wait but it might be a long wait. Good luck!