Species Highlight: Carpenter Bees

At UC Berkeley’s Urban Bee Lab, we often take our specimens to different events to educate the public and gain interest on both bees and our mission. The bees that seem to stick-out the most at these events are the large, male fuzzy-bodied Xylocopa, a genus of carpenter bee. While some people find the carpenter bee undeniably cute, others are alarmed to know that such a large bee could exist. While controversial, the carpenter bee is an important and eye-catching part of California’s ecosystems. 

The carpenter bee, of the family Apidae, defies many of the assumptions people have regarding bees. To most, bees are flying insects with stingers, living in hives and making honey; while this is true for some species, these are mostly clichés we have gained from the common honeybee. Carpenter bees, like the majority of bee species, are solitary. This means that they do not belong to a hive–in fact, carpenter bees do not live in a hive at all. As their name implies, carpenter bees burrow inside older, softened wood or pithy stems using their mandibles; so, if you have some old furniture laying outside, it may be home to a carpenter bee. 

Another common comment we receive when tabling is, “Wow, I wouldn’t want to get stung by that”. Understandably so; however—to ease the minds of many—being stung by a carpenter bee is quite rare. Female carpenter bees rarely sting, unless provoked. Male carpenter bees, on the other hand, do not have the ability to sting, in fact, this is true for all male bees. Their inability to sting, accompanied by their engaging look, makes male carpenter bees great insects for environmental education. In fact, the male valley carpenter bee (Xylocopa varipuncta) is often referred to as the “teddy-bear bee” due to its golden color and enthralling fuzziness; despite this nickname, we still would not recommend cuddling any bees. 

Even with my previous descriptions, not all carpenter bees are large and velvety. They can range anywhere from 3 mm to 10 cm in length. For reference, carpenter bees of the genus Ceratina are often less than one centimeter long, while the Xylocopa latipes can grow up to ten centimeters. Furthermore, carpenter bees come in a variety of colors including black, yellow, and green. The Xylocopa aerata is a carpenter bee of a beautiful emerald green color with a gold luster—similar to that of a June beetle. 

When it comes to pollinating, carpenter bees are generalists, meaning they are not picky with the flowers they pollinate. This makes carpenter bees good pollinators of many plants in urban environments and wildlands. Their ability to pollinate is also dependent on their tongue and body size; some carpenter bees, like the Xylocopa latipes discussed earlier, are unable to reach the inside of certain flowers. Being the opportunists they are, carpenter bees with shorter tongues or larger bodies will commonly resort to nectar robbing. Nectar robbing occurs when an insect, in this case the carpenter bee, uses its mandibles to make a small incision in the base of a flower, thus giving it an opening to collect nectar. While most bees are attracted to yellow, blue, and white flowers, carpenter bees will often rob the nectar of red flowers. At the Urban Bee Lab garden, we have seen that carpenter bees are particularly attracted to red salvias as a source of nectar. After the nectar is stolen, it is common for secondary robbers to use the same incision as the primary robber—honey bees are known secondary robbers. 

When it comes to carpenter bees, their presence is undeniably controversial. They are often seen as pests due to their tendency to burrow into wooden structures. Pest control; however, does not have to be fatal, as pesticides often do far more harm to the area than good. Afterall, bees—and 
many other insects—are a crucial part of our ecosystem and food chain. Introducing pesticides into the environment will not only harm the bees, but also other beneficial species. So, if you happen to find a carpenter bee burrowing in your home, think twice before doing it any harm. There are many non-fatal methods of removing carpenter bees, the most easy and ethical include the use of artificial wasp nests (available on Amazon), relocation, and plugging the burrows with steel wool. There are also more crafty methods, like building your own bee hotel (it's like a birdhouse, but for bees!). We will include helpful links and articles regarding carpenter bee removal below: 

1. Artificial Wasp Nests for Purchase 
https://www.amazon.com/DECYOOL-Hanging-Deterrent-Hornets-Jackets/dp/B088CVZR8V/ref =asc_df_B088CVZR8V/?tag=hyprod-20&linkCode=df0&hvadid=459707536545&hvpos=&hvn etw=g&hvrand=13294011571963622054&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl= &hvlocint=&hvlocphy=9032083&hvtargid=pla-942641387660&psc=1 

2. Bee Hotel Tutorial 
https://www.foxleas.com/make-a-bee-hotel.asp#:~:text=All%20you%20need%20is%20a,these% 20tunnels%20as%20nest%20sites. 

3. Carpenter Bee Removal Methods 
https://www.popsci.com/diy/get-rid-of-carpenter-bees/ 

4. Information Regarding Carpenter Bees and Other Bees Found in California Gardens https://anrcatalog.ucanr.edu/Details.aspx?itemNo=3552-2 

​5. More Information on California’s Bees and Flowers 
https://www.amazon.com/California-Bees-Blooms-Gardeners-Naturalists/dp/1597142948