Michael emailed me with a question on setting out new nests when the old nests are getting filled. He asked if adding a nest close to the others would disorientate the bees already nesting at the location.
I suggested that additional nests are best set out in the visual range and clustered close to the original nests.
Michael also noted that his bees headed for the tubes first. Yes mason bees prefer round holes, especially when the substrate is wood or carboard. Unfortunately the bees’ choice is not always the best for eaze of management.
Michael’s original question was:
If I need to set out more nesting sites for the Mason bees should I put them next to existing sites, or, put them a bit away from the one’s I originally set out? The reason I ask is that I am getting many more bees to nest so far this spring compared to last year but I do not want to mess up the bees visual cues to the old sites. I also know they like to be near each other. Your thoughts?
Michael’s follow up notes are:
As I mentioned before I was particularly surprised by what happened this spring when most of the O. lignaria emerged at once with a very low dispersal rate. This activity was in contrast to the last two springs where the dispersal rate was high and emergence rates were very sporadic.
In my nesting set-ups, which I have two of them around my house (see the BEFORE photo), I put 40 cocoons in the wooden house, and 20 cocoons in each of the tube units (80 total of O. lignaria). There was also 20 of your O. californica cocoons in the wooden nursery house.
I set out all of my bees on April 20 and to my astonishment, almost all of O. lignaria had emerged by April 22, and the first mud nests were made in the tubes on April 24.
The second surprise was that all of the bees decided to move to the tube units (reeds and paper filled tubes). This is where I was beginning to get concerned that I would not have enough nesting sites. We had a week of very good weather, and then we had four-five days of cool and damp weather which I then decided to put another tube unit below the existing two tube units (see AFTER photo).
During this cool period of weather, I noticed that all the O. lignaria bees were resting in the tubes, so I kept track of what bees were in what tubes and how far they had gotten along in building their mud nests. The good news is that when the good weather returned last weekend that all of the existing bees resumed their normal activity and were not deterred by the NEW unit below! It seems that putting a new nesting house nearby did not distort their visual cues (at least under my conditions).
Also, in taking the pictures of my nesting sites last weekend I noticed the O. californica I purchased from you were beginning to emerge.
I just managed to snap a photo of a O. californica male and female bee doing what a pair of bees are supposed to do .
It might also be my imagination but it appears that the O. californica seem a bit larger than the O. lignaria, and so far all the O. californica bees are headed for the tubes.
Maybe it is some kind of social communication or interaction, but who knows what the bees are really thinking!