Help Native Pollinators With a Bug Hotel
Spring is in the air, and with warmer temperatures comes the re-emergence of many of our native bees and pollinators. Of the nearly 600 species of native bees in North Carolina, nearly 30% nest in aboveground cavities or tunnels. These mostly solitary bees are not aggressive, and some are said to pollinate even faster than honeybees!
Within a short window of time (often just 4-6 weeks), many species of solitary bee will emerge, mate, and need to find a suitable spot to lay their eggs. For cavity and tunnel-nesting bees, this often means the remains of old twigs, reeds, and other plant parts. One easy way to provide habitat when pruning back the garden is to leave long, 8-24” stems above ground on plants with hollow or pithy stems. Some common examples include hibiscus, sumac, raspberries and blackberries, black-eyed susan and other species of Rudbeckia, elderberry, goldenrod, and bamboo. Brush piles can also make attractive habitat for pollinator and wildlife species beyond bees, including many beetles.
A fun (and kid friendly!) way to add solitary bee habitat is with the creation of your own bee hotel. While many pre-made options are available, bee hotels can easily be created with supplies from around the yard, and your new tenants will appreciate them just as much! The main goal for any bee or bug hotel is to provide a diversity of cavity sizes to suit different species (a range of 2-12 mm is recommended), all of a length of at least six to eight inches. Solitary bees such as mason bees lay each egg in an individual cell within the cavity, placing food in each cell for the future bee larva, and finally capping the cavity with mud. Many bees place female eggs at the back of the tunnel, so if tunnels are too short only male bees will emerge the following spring.
Cavities can be a collection of pithy or hollow stems from your own yard, small bamboo pieces, cardboard, or even ordered supplies. Paper and plastic straws, while tempting, are not recommended, as they can lead to mold and parasite problems. It’s important to provide an external cover to protect from predators like woodpeckers, whether that means arranging materials in a coffee can or even a large piece of bamboo or pvc. Cavities should also be closed and protected on one end, but open on the other for bees to access. A slight overhang on the open end can help protect against excess moisture. Collections of less than 100 cavities seem to be best for keeping bee parasites to a minimum.
Once you have completed your bee hotel, find a south or southeastern facing spot in your garden and mount the hotel three to six feet above the ground. Orienting the hotel properly will help the bees warm earlier in the day to be able to begin foraging. Be sure to also clear any vegetation from the front of the hotel so that it’s easy to for bees to access. With that, sit back, and start welcoming your new guests. You’ll be amazed to see the little holes start filling with mud, and can feel good knowing you’re helping our native bees and pollinators!
Excited to learn more about bee hotels and their inhabitants? Learn more from these excellent resources:
How to Operate a Successful Bee Hotel – This recent addition to the Plants, Pests, and Pathogens series by Dr. Elsa Youngsteadt and Meredith Favre of NC State University discusses what insects benefits from bee hotels (minute 14), and how to build your own (minute 44).
The Bees of North Carolina: an Identification Guide – Wonderful publication from NC State University that will help you figure out just who’s visiting your garden! Very detailed with beautiful pictures.
Building and Managing Bee Hotels for Wild Bees – Comprehensive resource on building bee hotels from Michigan State University Extension.
Give Mason Bees a Helping Hand: Build a House – Further resources from the Master Gardener℠ volunteers of Buncombe County.