Our house in Poitou-Charentes is made of stones held together with mud. It is tradional and over the years it has gradually cracked and settled and had various materials added to it in order to prevent it from returning from whence it came.
The mud mortar is in some places quite soft and provides homes for much wildlife. Little bees and wasps make holes and lay eggs along with a food source inside and some time later the next generation of bees or wasps appear. This is all well and good but it does not help the integrity of the building.
There is a very good blog called A French garden which is about a garden in France – there’s a surprise – but amongst other subjects related to a garden in France there are quite a few references to bees, all sorts of bees including a type which are solitary and make or use little tunnels to lay their eggs in and which are known as Mason bees.
To visit the site click http://afrenchgarden.wordpress.com/2013/03/08/mason-bees/ Have a look at the page on Mason bees but then have a good look at all the other stuff- there is a lot of interesting material here and not just on bees.
The manufacturers of bird boxes, some years ago, hit on the idea of making boxes for insects, particularly bees. These are to put it simply a bundle of bamboo canes pushed into a nice box and then sold to armchair nature lovers. In the French garden blog you will see the sort of box I am referring to, only the ones in this particular French garden have been made by Mr French garden at a cost no doubt significantly lower than the ones you can purchase from the advertisers in the RSPB magazine. Also Mr and Mrs French garden will have no doubt gained a considerable amount more satisfaction from their DIY efforts than if they had bought one ready made.
Yesterday I was clearing up a bit in the garden, my French garden, and came across some sticks which were hollow, like bamboo, which came from an Empress Tree (Paulonia) and so I decided to construct a primitive bee hotel. It is really more of a bee hostel than hotel, certainly not the 4 star accommodation that’s on offer in the French garden residence. It is just a bundle of sticks tied together with string and I stuffed it under the tiles of an outbuilding.
Flushed with enthusiasm I then decided to try another approach which was to drill lots of holes in an old oak log which sort of doubles up as a bird table. I used two different sized drill bits so any homeless bee or wasp has a choice of a large or medium hole.
After all this exertion! I then sat back to read a book about insects and see what creatures might make use of my holes.
There are a lot of creatures which make holes and lay eggs in them. It’s not just Mason Bees. Here is a summary.
Wood Wasps. These can be quite large and have what looks like a nasty sting. In fact it is not a sting but is an ovipositor which is for laying eggs. These creatures bore a hole in wood, lay an egg and the grub then feeds on the rotting wood.
Potter and Mason Wasps. These wasps either make a little chamber out of mud and saliva, similar to termites but on a less grand scale, or they excavate a hole, into which they place caterpillars and then lay an egg. The grub feeds on the caterpillar. There are variations on the theme. Some species paralyse the caterpillars so that the grubs can feed on ‘fresh meat’ and one species continually tops up the food supply by bringing regular supplies of caterpillars.
Sand wasps and Digger wasps.These vary considerably in shape, size and habits and there are over 100 different types in the UK. However they are all solitary, all make a hole for laying an egg in and all provide paralysed insects for the grub to feed on. They normally make their holes in the ground especially if it is sandy so they are probably not responsible for holes in my walls.
Mining Bees. Again this is a huge group with over 100 species in the UK alone. They are similar to the wasps in that they make a hole for their eggs but they may lay several eggs in one hole. Each egg is in a separate chamber and the big difference to the wasps is that the bees provide food in the form of pollen and nectar or honey. This group is split into several different types. Some collect pollen in baskets on their hind legs like the normal honey bee, others do not have baskets and so collect the pollen on their bellies and another group cannot collect pollen at all and so they have to rely on other bees to do this for them. These are called Cuckoo bees.
Finally there are some parasitic wasps and one which we get a lot is called a Ruby-tail wasp (Chrysis ignita) This is bright coloured red and blue. It is small and totally manic. It lays its eggs in the hole of another wasp or bee and its grub is parasitic on the grub of the bee or wasp.
So there you have it. There are several hundred different insects that make holes and getting to grips with them is all a bit of a mine field! Get it….. mine field…. Mining bees. Finally though I would reiterate that a visit to the French garden blog will help you identify some of the more common ones.