The answer: When it is a moth.
True bumblebees are all over my bluebeard shrub (Caryopteris ‘Blue Mist’) and all over any late blooming flower in the garden, honeysuckle, lantana, butterfly bush, wild ginger, asters, etc. If you’re weeding nearby or just admiring the insects, you might spot one ‘bee’ that is not like the others. The black and yellow colors seem right but this odd bumblebee will hover over the flower while it feeds unlike the other bumblebees that bump and collide and crawl over blooms to feed.
This odd-looking bee is not a bee at all. It’s a Bumblebee Moth, a Snowberry Clearwing Moth, Hemaris diffinis, and it is a pretty darn good bumblebee mimic. You’ll see it flitting around the garden feeding during the day just like the bees. Any predators should recognize the familiar yellow and black warning pattern and steer clear of the potential sting. Except this little yellow and black moth is completely harmless. It’s simply a moth.
The caterpillar of the moth is pale green on the back with darker green along the sides. There are numerous flecks on the body and a horn of bright yellow at the base with a black tip on the top. Although related to the tobacco hornworm, this bumblebee moth caterpillar will eat the snowberry, honeysuckle, and cranberry viburnum…. NOT your tomato plants! Be kind to these caterpillars.
Interestingly, the snowberry plant, Symphoricarpus albus, that gave the insect its name is a hardy deciduous plant in the honeysuckle family that was brought back to the east with the Lewis & Clark expedition. When it reached Thomas Jefferson, he was enthusiastic about the plant with the lovely pink blooms followed by large pure white fruit, and penned “some of the most beautiful berries I have ever seen.” It’s deer resistant, great for cut flowers, likes shade and these little bumblebee moths like it. That’s all the persuasion I need. I think I must have a few snowberry plants in this garden next spring…. perhaps in the shade of the new secret garden!
Ann Hohenberger, the Garden Club of Gloucester