Page 36 - ALG Issue 4 2017

General
Red Mason Bee
Beekeeping without the sting!
Red mason bees are a univoltine (single brooded) spring ying solitary bee, active from April to mid-June and occasionally a little later. They are approachable and docile little bees which are not given to stinging and so are safe around children and pets. Like all bees it is only the females that carry a sting and it has been said that the only way a female red mason will sting you is if you catch her and roll her between your ngers! Because of their docile nature they are the perfect pollination partners on allotments and in gardens.
Red mason bees are hugely bene cial to our gardens and
crops as they are excellent pollinators of fruit trees, raspberries, strawberries and early vegetables together with a wide range of wild owers. A single female red mason bee can do the pollination work of 120 honeybees and may in the future be commercially reared to pollinate fruit orchards in the U.K. Like all cavity nesting solitary bees, red masons collect pollen on the underside of the abdomen on rows of stiff hairs called a scopa. During each ower visit a little of the collected pollen falls off and so many more owers are pollinated than is the case with honey bees for instance. This is what makes solitary bees a true gardener’s friend.
Life cycle of the red mason bee (Osmia bicornis) - Male red mason bees emerge around two weeks before the females. When the females emerge, they are mated by the waiting males and immediately set to work establishing a nest. Red mason bees use mud to build a linear row of chambers that they provision with a mixture of pollen and nectar into which an egg is laid and the cell
is then sealed and work begins on the next one. It takes a female red mason bee between 1 -1.5 days to build and provision one cell. The eggs hatch after about a week and the resulting larvae eat the pollen and nectar in the cell. After around 56 days the larvae spins a cocoon and remains in this state within the cocoon for a further 48 days before metamorphosis into an adult bee takes place. The bees then remain quiescent within their cocoons until emergence time the following spring. The sole function of the male is to mate with as
A mating pair of red mason bees
Red Mason bee
many females as possible, drink copious amounts of nectar and eat pollen (well, boys will be boys!) The males die off after about 6 weeks and the last females are active until mid to late June when they too perish. No red mason bee ever lives to see its own offspring.
Male (unfertilised) eggs are laid in the cells at the entrance end of the nest (left) and these are the rst to hatch out in the spring. The end cell is always left empty and sealed with a thicker wall of mud than used in cells containing the eggs. This is a form of protection from predators and other species of bees and wasps which might otherwise nest in the vestibular cell and make it impossible for the red masons to emerge from the nest in spring, thus causing them to starve to death. The cocoons consist of two layers, an inner silky lining and a surprisingly tough outer layer. The cocoons are white when spun but soon revert to the familiar brown colour shown here. On hatching, the bees secrete a substance that softens the outer layer of the cocoons to aid emergence.
Attracting red mason bees to our gardens and allotments is quite a straightforward task. They need just three things, owers, a supply of mud and somewhere to nest. Bees look for a nesting site along
a linear edge as provided by a hedge or fence. Bee nesters work well as long as the tubes are at least 160mm long and of suitable diameter; 6 to10 mm is ideal. As well as red masons, a range of different diameter tubes attracts other cavity nesting bees such as orange vented and blue mason bees followed by leafcutter bees later in the year. The nesters should be sited preferably facing south in a sunny but sheltered position at about eye level if you want to watch the comings and goings during the season. I always build my own as some of the ones for sale on the open market are of dubious quality and during the winter all of the cocoons and tubes are removed and cleaned ready for the following spring. I have a fact sheet all about this process and would be happy to send it out to anyone who wishes to know more. Contact me at ronrock@phonecoop.coop for your copy.
Ron Rock
Ron is a volunteer with the British Bumblebee Conservation Trust https://bumblebeeconservation.org/ , writes on their blog and runs events.
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