All about Pollinators Series: Carpenters ​- BIG ​and ​little ​!

Welcome to prime time “World of Pollinators”! July , August and September are such active months – flowers are celebrating with their riotous blooms of bright colors and lucious aromas, and the pollinators are taking full advantage! Have you noticed an increase in the activity- that lovely summer song of buzzing bees, the swooshing of wings and the chirping of crickets cicadas and katydids ( OK , that last group aren’t necessarily pollinators, but they are part of the chorus!)

As promised, I’d like to talk about Carpenter Bees- the big ones and the little ones , although they are not related! Carpenter bees ( Zylocopa virginica) that we see (fluffy yellow in the front and shiny black in the back) are known mostly for their size- about an inch- and their nesting habits – which can make them not very popular. You see they make their nests in rotting wood or human-made structures like lawn furniture, fences or even the siding on buildings. The females will chew out a perfectly round hole about the size of the tip of your little finger and go straight in, then turn 90 degrees to follow the grain of the wood making a nest tunnel. Since adult Carpenter bees overwinter as adults and come out early spring, mating occurs usually in April and it is after this that the females construct the nest. She puts nectar and pollen in the tunnel, lays an egg and closes each section with some of the saw dust. It is the mother that feeds her young, cares for the nest and does the foraging. The other females guard the nest as do the males and they winter over huddled together until emerging, mating and going off to find new nesting sites. Because of the effort required to make the nest tunnel many are reused.

One may think that because of this behavior Carpenter bees may not be worth it, but, as such large bodied bees who are generalists ( they will go to many different flowers) their pollinating activities are more beneficial than their nesting habits. So, when you are out looking at bees- remember- they are the big yellow and black ones with a “shiny hiney” – easy to spot, and the males (which can’t sting) are also easy to ID- they have a white or yellow spot right in the middle of their forehead! During my visit to the Butterfly Garden this week I was able to see Phlox merrily being visited by primarily lady Carpenter bees, and one or two boys. If you see one, that white spot is quite noticeable!

At the opposite end of the size spectrum we have Small Carpenter bees- or Ceratina! They are all black and less than a half inch long. Girls have an hour-glass shape and may have a small white or cream line or spot on their face. The males are also black but the white or cream area on their face is like an upside-down “T”. They have earned their “Carpenter” name because the females make their nests in “cavities” – in the pith-filled (soft paper like) center of the stems of dead plants/flowers. They enter the open end of the stem that preferably is standing upright and chews out the pith center. She will then put nectar and pollen in the tunnel, lay her egg and use that stem pith to wall off that brood cell before going onto the next one. When finished, she will perche at the entrance to guard her nest. Small carpenter bees overwinter as adults and emerge in the spring. Because of this nesting habit consider leaving the dead stalks of your
perennial plants alone in the fall and only cut them to 15” above the ground in the spring – the new stalks will hide the old and you’ve provided a home to these cavity nesting bees!

Because of their small size, Small Carpenter bees ‘ even though generalist forages , tend to go to flowers with smaller florets. In the fall you may see them on Goldenrod and Asters, but look carefully – they are small (but mighty!)

So- lots to look for this week, but fairly easy to identify, and the names are easy to remember – it”s where they build their homes, and how they do it!

Have a wonderful week – keep alert to those sights, sounds and think about what/who you are seeing and hearing – write it down or take a picture- or draw one! Make up a storey- so many ways to enjoy these magical gifts of Nature!

By Mary Brennan – Holden Volunteer, Volunteer Pollinator Specialist