The temperatures have been swinging from freezing to near 80’s, the dogwoods have blossomed, the pine trees are spewing pollen over everything: spring here in Georgia. I know, spring doesn’t officially start for another week, and while the calendar doesn’t say so, it is officially spring to me. And with the onset of spring, I saw my first swarm.
(A single tree can release 40oz of pollen!)
Nope, not termites. Carpenter bees. Carpenter bees are cool insects, great pollinators, and for many people, they are scary and need to be controlled. Here are some facts about carpenter bees and what to do about them.
There are two groups of carpenter bees: the large carpenter bees and the small carpenter bees. The common ones we see in the US are the large or Xylocopa sp. There are actually 9 different species in North America and over 400 species world wide. The genus name, Xylocopa, comes from the Greek for “wood-cutter”. Pretty applicable name!
As with other "pests", there are plenty of DYI methods you can find online. Like most DIY methods, they are inefficient at best, damaging at worse. A Cornell study looked at the common carpenter bee traps and tested them to see if they were effective. They did catch carpenter bees. There were slightly more females than males captured and this is good because it is the female that is going to chew into the wood and cause the damage. While it was a small study, half of the bees they captured were from a single site that had extensive damage from years of carpenter bee activity. I guarantee there are hundreds swarming around my one plant this weekend so that’s not a lot of capture. Lastly, there was “abundant capture” of other insects, many of which were beneficial pollinators. So the DIY trap: probably not going to significantly reduce the population and it will take out other native pollinators.
A study done in Ontario Canada found as few as two brood cells in a nest and as many as 21. On average, about 38% were males which means more females to excavate nests.
Carpenter bees can be lazy… or maybe economical is a better term: they will reuse old nests. In fact, the same Canadian study showed over a five-year period that more nests were reused than newly constructed ones. This means that no new damage is incurred in a structure. It does mean you can treat old nests early in the spring to potentially prevent re-use.
Adults overwinter in their wooden homes, and males emerge before females. This means as soon as those first males are seen flying around, that’s the time to look at preventative measures. Look to seal, paint, or otherwise treat up any unsealed wood, look for past damage and seal and/or treat those spots.
They aren’t social (no sharing of brood care or overlapping generations). They aren’t completely solitary either. Two to three females are often present in one nest. In these cases, only one is laying eggs though.
Females can live for two years.
Despite what people may think, these bees are not aggressive or out to "get" people. While males may be patrolling areas and seem aggressive, often flying at people, they are harmless. Males can not sting, and females have rarely been recorded to sting. The key to keeping carpenter bee populations lower around structures (where people are) is to treat the wood by painting or sealing it in some way. The females will only chew into untreated wood. These bees are a great pollinator to have around and while structures should receive preventative treatments, the bees should not be treated.
Are you prepared for the swarm? For more on how we can help you with carpenter bees or any urban pest, contact us here!
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