Masonry and Mining bees are both solitary bees. Like all bees they are important pollinators of plants, but unlike honey bees and bumble bees they have no workers and have no collective nest. Mortar bees excavate chambers in soft mortar joints in brick walls (approximately 20mm deep) and Mining bees will excavate chambers in soft/sandy soil. Although they are solitary they do excavate their chambers close together and thus give the impression of being a colony and occupying the same habitat.

These solitary bees:

• are harmless (do not sting)
• are beneficial
• they do not pester people, and
• they do not damage buildings

They look much like honey bees but are generally a little hairier.

We get a lot of calls in late April and May for bee/wasp problems are in fact solitary bees. Solitary bees are however beneficial  insects and non aggressive and we will not, therefore offer an eradication service. Some customers call us when they see these solitary bees entering their homes trying to find somewhere quiet to die. They are often confused with honey bees causing concern about the possibilities of stings etc. If you find these bees entering your home, hanging around the windows and acting in a sleepy dopey way in the months of May and June then they are more than likely harmless solitary bees.

Life Cycle

The males and females are active from late April - mid June. On warm sunny days during this period they are busy constructing their chambers in mortar joints or soft/sandy soil. Despite popular belief mortar/masonry bees do not damage brickwork and mortar, and only take advantage of existing decay. They invariably choose areas that get a lot of sun and are frequently seen on South-facing elevations of buildings.

The bees lay their eggs in their chambers, which they also stock with pollen and nectar. The chamber is then sealed.

The eggs hatch out as a larvae. This feeds on the pollen and nectar left in the chamber. The larvae then pupates and subsequently hatch out as a bee and emerge from the chamber. The period of time from egg being laid to the bee emerging may take up to a year. The adult bees only live for a short period of time – approximately April – July and the parent bee will therefore have died before the offspring emerges.

Identification of mortar/masonry/mining bees

These bees are small bees with a similar shape to a wasp - they are frequently confused with wasps or honey bees. They are active during April, May, and early June with the peak of activity in May - too early to be wasps.

Mortar/masonry bees are invariably seen on sunny days and are active in sun facing elevations of buildings. Their activity appears a little confused as they hover over their territory looking for their egg laying chambers. They sometimes block airbricks and keyholes with mud used to construct egg chambers.

Mining bees are found on sun drenched areas of ground.  Holes in soil created by mining bees are approximately the diameter of a pencil and are distinguished by a heap of soil around the rim.

The bees pay no attention to people and are barely able to sting if handled.

If bees are reported active over a wide area, or tend to move with the sun, and are only seen on sunny days over a period of time, then they are probably solitary bees and not honey bees.

Treatment

Mortar bees are beneficial insects and do not sting. Furthermore, the spraying of insecticide is generally unsuccessful as:

• the bees are only found in sunny elevations and insecticides break down with UV light and
• the eggs etc are protected from the insecticide as they are sealed into their chambers.

Mortar bee activity can be discouraged by re-pointing areas of damaged mortar on walls and chimneys. Mining bee activity can be discouraged by watering and raking over the ground where their holes are evident.