Blue
Orchard Bees
What are they?
Blue Orchard Bees
(BOBs) are native North American bees. They range throughout most of the United
States and southern Canada. They are also called orchard mason bees
and scientists know them as Osmia lignaria. They are beautiful insects, about
1.3 cm (0.5 in.) long and blue-black with a metallic sheen. Unfortunately, they
are sometimes mistaken for large flies. (Look closelythey have 2 pair
of wings and are not interested in garbage!) The females are somewhat larger
than the males and the males have a white, hairy face. Like all bees, mason
bees collect flower pollen as a protein source for their young and get their
energy from flower nectar. In shopping for their "groceries", they
carry pollen from flower to flower, achieving pollination.
A number of things set BOBs apart from other bees:
Solitary but
Like Company
They are loners--each female bee builds a nest by herself cell by cell, lays
eggs, seals the nest, and then repeats the process. She receives no help from
other bees, so there is no colony or hive as in honey bees or bumble
bees. But despite this, BOBs are attracted to each otherthey like to build
their nests together in aggregations.
Build with Bricks
Like the wisest little pig, BOBs build their nests with bricks (sort of). Each
egg chamber in the nest is sealed with a partition of ordinary mud. The entire
nest is also sealed with a hardened mud capping. This is why they are called
mason bees.
"Instant
Bees"
Mason bees develop as larvae through the summer and turn into adults in the
fall. Then they rest during the winter, ready to emerge at the first sign of
blossoms in the spring.
Perfect Pollinators
many varieties of apples, cherries, plums, peaches, and similar stone and pome
fruits. Because they specialize on these plants, they are exceptionally good
at pollinating them. They will forage on other flowers as well. They are adapted
to a cool climate and can fly in chilly, even drizzly weather. Thus, they can
be busy pollinating when honey bees remain inside the hive. Individually, a
female mason bee is several times as efficient as a honey bee worker in pollinating
fruit trees. These features make BOBs the perfect pollinator for those who have
a small number of trees or bushes but may not want to manage honey bee hives.
Safe
As with other solitary bees, BOBs are gentle and shy. The female has a stinger
(actually it is an egg guide), but she uses it only when in serious danger,
as when she is purposely caught in the hand. Mason bees do not attack to defend
their nest or arouse each other in alarm but simply flee when disturbed. Therefore,
they are totally safe, even around children and pets.
Keeping Blue
Orchard Bees
Female mason bees make their nests in hollow cavities. In nature, these are
found under the bark of trees or in the emergence holes of tree-eating grubs.
They adapt well to man-made environments and frequently nest under shingles
and siding. Mason bees can be attracted to your yardthey may already be
in your neighborhood, especially if you have a garden with fruit trees or berries.
To make mason bees a permanent part of your home orchard, simply provide them
with nest holes and make sure they have plenty of flowers to feed on. The ideal
nest hole is 8 mm (5/16 in.) in diameter and 7.5 to 15 cm (3 to 6 in.) deep.
The bees will nest in a wide variety of such cavities: straws and holes drilled
in boards are commonly used. But to produce happy and healthy bees and to avoid
disease build-up, you should give the bees quality housing. This means a dark,
closed-bottom cavity with smooth, porous walls that can be renewed each year.
Mason bees are a fascinating wild creature that can be easily encouraged to
colonize the backyard garden environment, to the benefit of the gardener, orchardist,
homeowner, and nature lover.
Problems
Blue Orchard Bees have problems, just like all creatures. They have certain
requirements in nest placement, preferring a warm, dry, situation. They must
have adequate flowers to raise their brood. And finally, they are subject to
diseases, parasites, and predators. These include fungal diseases of the developing
bees, various types of mites which compete with the larval bees for food or
eat the bee larvae, a variety of parasitic wasps, spiders, and larger predatory
animals like woodpeckers, crows, and squirrels.
Entomo-Logic
Straw Systemthe Best You Can Do for Your Blue Orchard Bees
Bare wood holes are acceptable to mason bees, but over time they become fouled
with debris, germs, and parasites. If not cleaned, the hole subsequently loses
its attractiveness to the bees as a nest cavity. Mason bees tend to go
away from such nest boxes after the first year or two. Diseases and parasites
may build up in unhygienic nest boxes. The best nest system for orchard bees
is a smooth wood hole with a porous insert or liner that can be replaced each
season. This is the Entomo-Logic Straw System. The concept of straw inserts
was developed by USDA scientists. We have perfected the system and offer custom-made
straw inserts and carefully crafted wood boxes. The boxes are easy to maintainsimply
remove the filled nests in the fall and replace them with clean inserts for
the next spring. The new bees in their nests can be stored safely until it is
time for them to begin the nesting cycle and pollinate. Then, simply place the
nests near the nest boxes and allow the bees to emerge and re-nest in the new
inserts.
Frequently Asked Questions
Q
Where do I put the nest box?
A The ideal place is on the south
or east side of a structure (house, garage, shed, etc.) under the eaves. The
box should be protected from rain and wind and should receive morning sunshine.
Put the box up high out of the reach of pets and children. On a 2nd or 3rd story
is fine if you have a balcony or deck. The bees will find flowers to pollinate
up to 200 m (600 ft.) yards away, although the closer they are to their food
plants, the better. DO NOT put the box in the open or under a tree unless there
is no suitable structure for a long distance. Sometimes hanging the box on a
fence works.
Q
What do I do with the mason bees when they arrive?
A The bees will be diapausing (~hibernating)
in their cocoons in the nest tube when you receive them. Refrigerate them until
spring or keep at outdoor (cool to cold winter) temperatures. Then release them
near the nest box. See our leaflet "How to Care For and Use Entomo-Logic
Blue Orchard Bees" for more information.
Q
How do I set out the bees to pollinate?
A Three days to a week before bloom
begins, put the nest tubes or loose cocoons in your Entomo-Logic Ship/Release
box and attach to the bottom of the nest box. If you do not have a Ship/Release
box you can use a container such as a juice can or paper bag with a 9-mm (3/8-in.)
exit hole. Attach the container adjacent to the nest box so when the adult bees
emerge they can crawl up onto the box to sun bask and mate. DO NOT put the occupied
nest tubes in the nest boxput only fresh (empty) straw inserts in the
box for the new nests the emerging bees will make.
Q
What do I do with the filled nests?
A The developing larvae in their
straw-lined nests are very fragile. They will develop in summer over the course
of 2-3 months. You may either leave the nest box undisturbed during this time
or gently take it down and store it in a warm, safe place sheltered from vibrations
and predators. By the end of the mason bee flight season (around June 1st ),
you may notice deterioration of the nest plugs or many tiny parasitic wasps
around the box--these are good reasons to move the box to safety. By autumn
(usually September) the new generation of mason bees has matured into adults
in cocoons and can be handled safely. At this time or later, remove the filled
nests from the box, discard any empty or suspicious looking nests, and refrigerate
healthy nests until the following spring. The Entomo-Logic Ship/Release box
makes an ideal storage container. See our leaflet "How to Use the Straw
Insert System" for more info.
Q
Do BOBs sting?
A As with all bees, the female
blue orchard bee has a stinger, actually an egg guide, which she may use to
defend herself. However, because they are solitary and extremely shy, mason
bees will not sting unless handled directly. Since they are also wary and fast,
it is unlikely you will ever be stung by a mason bee. The sting is somewhat
less painful than that of a honey bee. Because the sting shaft has no barbs,
the female mason bee survives after stinging and can sting again. Male BOBs
have no stinger.
Q
Will BOBs pollinate my avocado-orange-lemon-macadamia-loquat-etc. tree?
A The orchard mason bee, Osmia
lignaria, has a strong preference for the pollen of cherries, apples, plums,
pears, and many other pome and stone fruits and berries in the family Rosaceae.
This is what makes them very efficient pollinators of these fruits. The bees
will seek out and concentrate on such flowers. But they are also known to collect
pollen from many other plants. (Pollen is the only source of protein for the
developing bee larvae.) The bees will visit an even wider variety of flowers
for nectar, their energy source. Some of their favorite nectar flowers include
rosemary, garden kale, and Phacelia, but other species may be visited. Obviously,
the bees can only visit flowers that bloom during their flight season, which
lasts about 2 months. We can not guarantee that the bees will visit the flowers
of your favorite plant but suggest you try them out. Keep in mind that other
wild bees that take up residence in the nest box may also pollinate the target
crop (see below).
Q
What else lives in the nest boxes?
A Depending on where you live,
the nest tubes may be used by other species of Osmia (other mason
bees), leafcutting bees, potter wasps (beneficial caterpillar hunters), or by
other species. Most insects that nest in the boxes are beneficial except the
parasites that live on them. Mason bees are usually the first to colonize the
box but are often followed by leafcutting bees if the box is left hanging and
there are uncolonized holes.
Q
Will BOBs live in my area?
A The Blue Orchard Bee, Osmia lignaria,
is native to most of North America except the desert southwest and parts of
the southeastern Gulf states. The species thrives in temperate climates (cold
to cool winters) and in mountainous regions. They are an adaptable species and
may be abundant in suburban areas and around farms near wild habitat.
Q
Do BOBs have mites?
A Mason bees are becoming popular
partly because of the problems honey bees are having with two parasitic mites,
the internal tracheal mite and the external varroa mite. These mites are specific
to honey bees and have no effect on mason bees. However, mason bees have many
pests, parasites, and diseases of their own, including some mites. Proper management
of your bees using the straw insert system to give the bees fresh nest material
each year is the best way to discourage build-up of these destructive organisms.
Pollen Mites a.k.a. hairy-footed mites can be controlled
with extra management procedures (contact us for up-to-date information on this.)
Q
How do the bees get out of the nest?
A Male eggs are laid toward the
nest entrance, so they emerge first. They jostle and arouse each other and come
out in succession. Females follow several days later. If one bee dies, those
below chew their way through it.
Q
How do I get the honey out?
A Sorry! Mason bees dont
make honey! They collect nectar from flowers but they burn it up immediately
in their nest-building and brood-rearing activities. Because they are inactive
during the winter, they do not need to put in winter energy stores, as do honey
bees, who are active all year. But mason bees are excellent pollinatorsthey
make FRUIT
ENJOY!
More detailed answers to these and many other questions may be found in the
illustrated, information-packed booklet:
How to Mange the Blue Orchard Bee
by USDA bee researchers Dr. Jordi Bosch and Dr. William Kemp.
Order it through our retailer, Raintree Nursery (see reverse)
©Entomo-Logic 2003
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Graphics female BOB, BOB on flower, larvae
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