Solitary Bees
Getting and Releasing Your Solitary Bees
Where and When to Get Solitary Bees
You can buy mason or leafcutter cocoons online. Mason bee cocoons are shipped in late winter / early spring when cool temperatures will keep them from hatching during shipment. If you can choose a delivery date, try to time it about two weeks before your fruit trees or berry bushes bloom. Leafcutter bee cocoons are usually shipped later in the summer. Time their arrival so that daytime temperatures are 75-89°F.
You can also attract solitary bees to your yard with lots of blooms and some well-placed nesting tubes, but these could be any species of solitary bee and not necessarily mason or leafcutter bees.
You could also get cocoons from a friend or neighbor! You can expect your number of mason bees to roughly double from year to year. Those that keep mason bees will eventually have more cocoons than they know what to do with, and may be more than happy to gift or sell them to you! On the other hand, leafcutter bees like to disperse, so you may actually see a decrease in numbers from one year to the next.
Mason Bee Cocoons
20 cocoons for a 200 square foot patio with flowers and 2 fruit trees.
100 cocoons for a 1/4 acre yard with flower beds and 8 fruit trees.
Leafcutter Bee Cocoons
40 cocoons for a 200 square foot patio with flowers and vegetables.
200 cocoons for a 1/4 acre yard with flower and vegetable beds.
Releasing Mason Bees
Have your bee house and nesting materials ready, as well as a source of clay mud available. After your cocoons arrive, store them in the refrigerator. If any of your bees have emerged, place them in a dark paper bag (still in the refrigerator) with a cotton ball soaked in a 1:1 sugar-water solution.
Once daytime temperatures are consistently above 55°F and there are open fruit blossoms or dandelions, you can start to release your cocoons and any hatched adults. Nighttime freezing temperatures are not a problem. Avoid releasing when there will be a 4+ day stretch of rain since the bees will not be able to fly or find food.
You may want to stagger your cocoon release by only putting out ⅓ or ½ of your cocoons at a time. This way you can extend your bee and pollination season. Make sure you’re releasing both males (small cocoons) and females (large cocoons).
Cut a hole in a small cardboard box, placing your cocoons inside, and pin it inside the attic of your bee house. This gives the bees a safe place to hatch. The smells from the cocoons also encourage the bees to return there to nest. Do NOT put individual cocoons into individual nesting holes. When the bees emerge, they will select their own nesting tube.
It can take days to weeks for bees to emerge, depending on outdoor temperatures. You may notice meconium (bee poop that looks like splattered paint) on the outside of your bee house. At first, it might seem like your bees have flown away and made their home elsewhere. This may be the case if they’re unable to find food or mud, but often it can take 1-2 weeks for bees to explore the area and mate before they come back to claim a nesting hole.
If you are staggering your bee release, put out more cocoons every few weeks. Store in the refrigerator in the meantime. Release your last cocoons no later than mid-May.
Releasing Leafcutter Bees
Have your bee house and nesting materials ready, as well as a source of preferred leaves (rose, lilac, hosta, dahlia, peas, beans, strawberries). After your cocoons arrive, they will need to be released as soon as possible. LEAFCUTTER COCOONS CAN’T BE STORED IN THE REFRIGERATOR like mason bee cocoons.
If temperatures are 75-89°F: Cut a hole in a small cardboard box, place leafcutter bee cocoons inside, and pin it inside the attic of your bee house. This gives the bees a safe place to hatch. Your bees should emerge in 1-10 days. Do NOT put individual cocoons into individual nesting holes.
If temperatures are >90°F: Cocoons will need to be kept indoors and released as they emerge. Intact cocoons can’t survive temperatures over 90°F.
If temperatures are <75°F: Release the bees anyway, but expect the bees to take longer (up to three weeks) to emerge.
It can take days to weeks for bees to emerge, depending on outdoor temperatures. At first, it might seem like your bees have flown away and made their home elsewhere. This may be the case if they’re unable to find food or preferred leaves, but often it can take 1-2 weeks for bees to explore the area and mate before they come back to claim a nesting hole.
If you had leafcutter bees last summer and have stored cocoons over the winter, this will be addressed later on in Incubating Leafcutter Bee Cocoons and (Circling Back to) Releasing Leafcutter Bees and Cocoons.