The Mighty Mason Bee

Mason bees

The mason bees are here! 

I am happy to report that the first mason bees have been observed emerging from their winter domiciles around the area! I understand that for most readers this might not be the most exciting statement, however let me tell you why mason bees are such fascinating and important native bees. That way, you too can rejoice as you see similar species emerging in the landscape around you this spring and summer.

Might Mason BeesDocile and easy to keep

In the US and Canada there are over 130 species of mason bee, however only 30 are native to the east coast. Mason bees frequently make their nests in hollow reeds, tubes, or holes in dead standing trees. They do not excavate nests themselves, instead preferring to use cavities that have already been made. It is easy to provide man-made housing for them if there are no dead trees in your area. This is one of the reasons that mason bees have been used in commercial pollination to great effect.

Every female is a queen 

Like the majority of our native bees, mason bees are solitary, which means they do not live in a nest or share labor to support a single fertile queen. Instead, each female is a queen in her own right and provisions a series of rooms, commonly called cells, with the food her young will need. An egg is then laid on the food and the cell is sealed. She repeats thisMight Mason Bees process until the nest is filled. These cells are sealed with different materials depending on the species of bee. Mason bees, in accordance to their name, use mixtures of clay, mud, sand, and small rocks to seal their cells. Like other bee species, mason bees are able to determine the sex of their offspring and lay females towards the back of the nest with males on the outside. This allows males to emerge first and be prepared for mating as soon as the females are ready, however it also ensures that any predators attacking the nest would eat males first. The scientific name for mason bees, Osmia, refers to the fact that they use specific scents to mark the entrance to their nests. This helps them to find their home while nesting near groups of other bees.


Little pollination machines

Mason bees are great to have around for several reasons. These animals are spring’s true pollination juggernauts. They areMight Mason Bees active in very cold temperatures that make honey bees retreat to their warm hives. Mason bees are also incredible pollinators compared to honey bees. This is due to the fact that they do not carry the pollen they collect in tidy baskets, known as corbicula, like honey bees or bumble bees. Instead, they prefer to dive right into blooms and cover as much of their body in pollen as possible. This ‘messier’ approach actually leads to more pollen falling off of the bee and pollinating the plants visited. This can be seen best in apple and cherry trees, where each mason bee can do the work of 300 honey bees.

Native vs. invasive 

Might Mason BeesNot all mason bees are native, however. There are currently over 20 known introduced species of bee in the states, including the honey bee. I have noticed the Japanese horned-face bee to be very common in this area. This solitary wood-nesting species was brought into the states in the 70s by the USDA in order to assist with crop pollination. Unfortunately, someone didn’t get the memo that we have plenty of excellent pollinators here already. It is unclear what ultimate effects these introduced species will have on our native populations, however they could very well be playing a role in the decline of our native blue orchard mason bees.


This article was originally published by The Sylva Herald.


  1. furtdsolinopv on August 9, 2018 at 4:50 pm

    You made several fine points there. I did a search on the issue and found nearly all people will have the same opinion with your blog.

    • sprigglys on August 9, 2018 at 9:31 pm

      Thank you so much for your kind words!

  2. Dale on January 2, 2019 at 3:07 am

    I am very interested in mason bees to help pollinate my small orchard and have been looking for a source somewhere close to my southe as mi location. would you happen to know of a source near my location. thanks, dale

    • sprigglys on January 8, 2019 at 4:12 pm

      Awesome to hear that you are interested in using these amazing bees! There are several questions that need to be answered before you move forward. First off, what do you grow in your orchard? This will determine which bees will be around when you need pollination. If you haven’t already, put up some wood nesting native bee housing ASAP in and around your orchard. This will help you determine the bees that are already in your area. Do not put them anywhere where they will come into contact with ANY sprays. As always use pesticides as a very last resort, carefully according to labels, and at minimum dosages that are effective. The best source for bees is the environment around you. There are most likely hundreds if not thousands of native bees already pollinating your orchards, you just need to help foster higher populations of them by providing housing, insect buffers to keep populations fed and away from any sprays, and other techniques. I do not recommend buying mason bees unless you are absolutely certain there are no other mason bees around, which is only very rarely the case. The mason bees available for sale could be non-native species that could end up harming the ones that have already been helping for years!

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