Mason bees are a solitary insect. This means that each nest is independent of others. However, it is most common to find several in close proximity of one another without conflict. Their territories can be quite extensive – over several acres – depending on local food and shelter. Mason bees will overwinter in prepupal and pupal stages. They are among the earliest if not the very first bee to begin pollinating. They are not too sensitive to bad weather and will readily work when most other bees will remain home in the comfort of their colonies. For this reason Mason Bees are highly desirable.
In case this is not what you’re looking for, we also have in depth articles on: BUMBLE BEES CARPENTER BEES DIGGER BEES HONEY BEES
MASON BEE BIOLOGY ^
As the weather warms, Mason Bees will begin to emerge and immediately start looking for nest locations. Nest sights will be cavities that are anywhere from 1 inch to several feet deep. Such cavities can be found anywhere and are generally preferred to be around 9/32 to 5/16 of an inch in diameter. Such cavities can be found in old tree stumps, rocks, the ground or even live trees. In fact, they will readily take advantage of old mud dauber and paper wasp nests! The size of these nests are just what most Mason bees like so in many ways, this is nature’s way of recycling! Once a suitable nest is located, queens will actively search for food – pollen – along with nest sealing material. During this time she will mate so fertile eggs will be produced as the nest is constructed.
Nests are constructed by first placing food in the chamber, next laying an egg on the food and lastly by sealing the egg and food with a type of plaster. This plaster is usually made from mud or some cellulose product like paper or old wasp nests. It can also be made from plant parts like leaves. Once sealed, the eggs will have all they need to develop and grow and one day they will emerge ready to continue the process. Since nests are dependent on a healthy supply of pollen, expect to have activity during any one growing season. For this reason northern territories may only have one generation active per year but southern regions could have several develop.
Mason Bees are generally passive and not very aggressive. However, they can sting and will do so if handled or aggravated. For this reason they are best left alone. However, the opportunity for nest sights which most any home or structure presents to Mason bees is so great that they can become a major nuisance if nesting is ignored. Furthermore, they can cause damage to both homes and plants which is unsightly and unacceptable.
MASON BEES ARE ACTUALLY QUITE BENEFICIAL ^
In fact, they are so desirable that many gardeners and farmers actively install MASON BEE HOUSES on and around their property. Hang them up virtually anywhere and either species will readily take advantage of the ideal nest sites they provide. Nesting bees will work the landscape in and around your property insuring healthy pollination. With Honey Bee populations declining, the installation of these homes can have a big impact on local plants. Furthermore, making such houses readily available will undoubtedly help reduce nesting activity on your house! If you have either Mason Bees nesting on your home or causing destruction to one of your favorite plants, you may not be too interested in providing them a house in which to live. However, it is very possible that such installations could dramatically reduce nesting on your home and should therefore be considered. The reason for this is simple. Either species requires a special type cavity in which to nest. They will actively seek such cavities but when none can be found their quest for nest sights can become a problem.
MASON BEE NESTS ^
Mason Bees will readily nest on any structure which presents a prime location. One of the more common locations they like to use are the weep holes found around windows and doors. Such weep holes are common on brick homes but are used more today then ever as a way to help keep moisture from rotting the structure. Furthermore, builders will commonly use tubing in these weep holes which Mason bees love! They will readily find such tubing and quickly nest in it. When sealed, the tubing will cease to function causing moisture and water problems for the building. Mason bees will also create their own nests when none are easily found. Either will chew through wood, mortar and stucco and though such chewing is usually not going to hurt the structural integrity of the building, it will certainly be unsightly.
Cedar and Masonite sided homes are not immune to this behavior and virtually any overhang will attract them to soffits and fascia boards. Holes in such areas are usually shallow and small but will certainly be both annoying and aggravating. Mason Bees have learned that most any home has an abundant supply of nest locations and taking advantage of them seems to be at an all time high. It appears that once a house has activity it will get more and more every year. This probably happens because if a structure has something unique about it which Mason Bees like, the young of the original nests will return to it attracted by the same features.
MASON BEE DAMAGE ^
Mason Bee nests on the home can become a problem but the damage they do to the structure is usually only superficial. However, in the yard, their damage can be quite real and have major impact on targeted plants. Mason bee damage is done when they remove leaves from plants by cutting away small sections. In fact, it is very common for them to find a shrub or plant and within a week, do significant damage to the foliage. When damage happens rapidly, the plant may never recover. Remember, leaves play an important role for any plant. Without them they are not able to create food and eat. Leaves which are damaged by one or two bees will probably just look odd. The bees will typically cut away circular sections which are about 9/32 to 5/16 of an inch in diameter. This removal generally happens on the outside edge of a few leaves. If there are a lot of bees active, certain leaves will begin to suffer huge tissue loss and die; some will fall victim to plant disease or other insects. If enough leaves fall off, the plant could die.
MASON BEE SPRAY ^
Plants which are targeted by Mason Bees usually have some characteristic or feature they want. For this reason a few sections of leaves removed turns into a few more and soon a lot more. Damage will happen quickly since these bees work around the clock.
If you find activity that is damaging a prized plant, we have two options that can be employed to keep them away.
MASON BEE REPELLENT ^
The first is a repellent. This treatment won’t hurt them but merely “warn” them the plant is not safe to approach and they’ll stay away. Commonly mixed with paint or stain, NBS is made with essential plant oils and insects will avoid where its been applied.
Add 3 oz of NBS to any standard PUMP SPRAYER and spray all plants you want to protect at least once ever two weeks. If this proves effective, stay with it. But if you find the bees coming back soon than every 2 weeks, you may have to switch to the Prothor listed below. Its water based and won’t “hurt” or injure any plant.
For a few plants in a 1/4 acre or less, our PUMP SPRAYER will do the job.
For large yards, our HOSE END SPRAYER is best suited. Add 15 oz to the sprayer, fill with water and apply over 10,000 sq/ft of turf/plants.
BEST MASON BEE SPRAY ^
For a more permanent solution, PROTHOR is the better option. It works as a “stealthy” non detectable spray and when applied to turf, plants your homes siding or anywhere bees are active, they will move through it not knowing its present. Within a few days they’ll pick up a lethal dose and die.
Mason bees are smart and will figure out what is happening so ultimately they will stay away from treated areas. Prothor is odorless, uses the same active found in Advantage Pet Treatments for fleas and ticks so its very safe for use in yards where pets and children are active since you’ll be applying it at a dose far weaker compared to Advantage.
To treat with Prothor, add 2.5 oz to our hose end (seen above) and add water to the 5 gallon mark. Apply the entire amount over 5,000 sq/ft of turf/plants/homes once a week till all activity ceases.
Due to the life cycle of this bee and the fact that they are very territorial, its very common for areas you treat to be free of bees one day but then have new ones move in a few days later to take advantage of the newly available area. This pattern can play out all summer if you have a lot of them in the region. For this reason, its imperative you spray on a regular basis and once a week seems to be enough for most any problem. At some point in time, you should diminish the local population enough so one day you’ll be able to reduce the frequency of treatments needed.
For pump sprayer applications, add 1 oz per gallon and spray the entire amount over 1,000 sq/ft.
Mason Bees are a common nuisance around and on the home. Since they are strong pollinators, placing a Mason Bee House out can serve you in two ways. First, by keeping the bees close by you will help insure healthy pollination of local plants and second, by making good housing available the local bees will be less likely to live on your home.
If you have prized plants being damaged by the Mason Bee, treat them with Prothor. Structures and other objects you wish to protect besides plants should be sprayed with Prothor too if they’re using the home for nests. Once you start repelling them the local activity will be forced to find harborage elsewhere and will learn to stay off treated surfaces. This is very important if you are having a problem with them infesting weep holes. Within a season or two of local treatments, nesting on the structure should be easy to control and if houses were placed out, you can still take advantage of the Mason Bees ability to pollinate.
CONTACT US ^
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