Native bee species, such as the Maine blueberry bee, are important pollinators of both wild and cultivated plants. Unlike non-native honeybees which live together in hives, many native bee species are solitary. Each female needs her own nest site.

Female solitary bees lay their eggs in hollow plant stems, such as raspberry canes, or in the holes made by other insects in dead trees and fence posts. Because the population of solitary bees is limited by lack of natural nesting sites, placing nesting boxes built from wooden blocks around the garden can increase the numbers of gentle bees at work there.

Building bee nest boxes can be a fun winter project for the entire family. The boxes can then be placed in the garden in early spring, mid-March to late April. Solitary bees start searching for nest sites in May.

A single female may lay up to 35 eggs with each tunnel of the box containing up to 16 egg cells. Within each cell, the female bee lays a single egg on a loaf-shaped provision of nectar and pollen. She then seals the cell with a thin partition of masticated plant material or mud. For the Maine blueberry bee, it takes up to 20 trips to blueberry flowers to complete one cell.

The eggs hatch into larvae (grubs) that feed on the nectar-pollen provision. They then go through a nonfeeding pupal stage. By late fall, they have become adult bees that remain dormant through the winter, emerging the following spring.

Solitary bee nest boxes are easy to make. Adults and older children can do the sawing and drilling while the younger children can personalize each box with a drawing done in water-based paint or markers.

Materials

A 2-by-6 pine or spruce board cut into 5- or 6-inch lengths

Metal 3/4-inch strapping tape (also called plumber’s tape) cut into 3-inch pieces

Screws for attaching the plumber’s tape to the back of the box

Nails to attach boxes to tree trunks or stakes

Drill with 5/16-inch and 7/16-inch drill bits

Saw

Water-based paints or markers

Construction

Drill 12 to 14 holes in the front of each block. Make half of the holes 5/16-inch in diameter, the other half 7/16-inch. This mix of sizes will provide nesting sites for more than one species of solitary bee.

Each hole should be about 5 inches deep. Adult female bees will not nest in tunnels that are open at both ends, so be careful not to drill completely through the block.

Screw the piece of plumber’s tape 1-inch from the top on the center of the back of the block. The tape should extend two inches from the top of the wooden bee nesting block. Take care not to screw through a tunnel!

Let the children have fun decorating the sides of the box using water-based paint or markers.

Placement in the garden

Mount the bee nest 3 feet from the ground on either a stake or tree trunk. Angle the front of the box slightly downward to avoid flooding by rain. Bees seem to prefer boxes that face the morning sun.

The above bee nest box design was adapted from nest boxes made by Theresa Guethler of Bucksport. Many thanks to Theresa for her help with this article.