New Bees in the Block and a Leafcutter.

New Bees
A few days ago I was delighted to see new bees exploring my bee house. Some are using the same sized holes as the mason bees and even some of the spare cardboard tubes and some have gone for slightly smaller holes that I drilled in a couple of logs. I watched them coming and going but not with any obvious leaf sections so I am wondering if this is another Osmia bee rather than a Megachile leafcutter. To my inexpert eye they look very similar!

     

The two photos show the same bee busy sealing up one of the drilled holes. She stands on the outside and works her way round the entrance sealing up the nest with chewed plant material.
She works from the rim inwards. It’s a slow process involving many trips backwards and forwards. Watching the bees returning to the bee house I am interested that sometimes they seem unable to locate the right nest.
One sniff seems to tell them if it is right or wrong, but rather than land and try another entrance they take off and seem to need to reorient themselves and zoom in again. Sometimes it has taken 6 attempts.

They enter head first with, I am assuming, pollen for the bee bread, then they back out do a neat turn and reverse in to, again I presume, lay an egg. They are active early, as soon as the first rays of sun hit the bee house, this morning it was 8am. But they move slowly, noticeably speeding up as they and the day gets warmer… but then so do I. 🙂

Leafcutter Cutting

Yesterday I was over by the lambs ear plant, looking to see if the woolcarders were about and happened to see a bee land on a nearby bindweed leaf. I have rather let things go here and “weeds” abound, the thinking is that something is better than nothing but now I find that this dreadful invasive plant has a use, because the bee rapidly cut a neat semicircle from the edge of the leaf and flew off.

They are fast…superfast. I ran to get my camera but the bee returned to her cutting twice before I could get a shot. I watched for about half an hour and she must have made 6 visits. She seemed quite choosy about which leaf, seeming to need a good starting point on the edge or to get into the perfect cutting position.

As she cuts, she rolls the leaf in half and  flies with the folded section held under her body. Once she cut a piece so large she needed to land and rest on another leaf before taking off again.  Despite being fairly near my bee house this bee was nesting somewhere else, she sailed over the hedge, up and away,


Here is my only reasonable photo of the bee in action.

And here the neatly cut bindweed leaves. The precise pattern is distinctive of leaf cutter bee activity. Other bee friendly weeds, field pansies and field poppy stems in the same shot.

There are many, much better photos of leafcutter bees in action on the internet and some short films…but it is nice to have my own record! I have not been entirely clear as to which leaves the leafcutters use. I know they like rose leaves, other books say “various” leaves.

But which ones and why? I wonder if they choose leaves which have chemical, possibly anti fungal properties. I wonder how they evolved this behaviour and I wonder at their industry and ingenuity. The wonderful French naturalist Jean-Henri Fabre who I have talked about before also pondered this. From “Bramble Bees and Others”

“the Osmiae make their partitions with mud or with a paste of chewed leaves; the Mason-bees build with cement; … the Megachiles made disks cut from leaves into urns; the Anthidia felt cotton into purses; the Resin-bees cement together little bits of gravel with gum; … Why all these different trades?”
Why indeed?

Close by the bindweed I have seen similar bees on the knapweed. You can see their funny and characteristic pollen collecting behaviour as they wriggle around the flower with uptilted abdomen transferring pollen to the stiff gingery hairs of the scopa. Again I am unsure of the species.

There is so much to learn and understand about bees and I am aware I am such a novice, but not knowing the exact species does not in any way detract from the sheer enjoyment of seeing them, hearing them and knowing you have provided a few of the right flowers.

Like the birds, bees come and go as they please. It’s the wildness of them all that I love so much.

More Megachile..The Lovely Leafcutter Bee again.

I have written before about these delightful bees in my post  “The Leafcutter Bee: Can  Opener of the Bee World” so no need to repeat myself, and I don’t have much time either.

I have made a rather slow start to this next lot of bees.
But you can, and should, go and watch two wonderful short films by the BBC Natural History Unit of these amazing bees chewing round holes in rose leaves and transporting the huge pieces back to their nests where they form them into leafy cocoons for their little ones.The speed is quite astonishing.
The films, complete with cooing wood pigeon soundtrack, are on the excellent site Arkive  http://www.arkive.org/megachile-leaf-cutter-bee/megachile-centuncularis/video-09.html.

Leafcutter bees don’t rely only on rose leaves but use also birch, ash, beech and many other leaves. (I have read that the serrated edge is significant but am not sure about it, but I can see how it might give them a good starting point).

Megachile concinna in Jamaica uses bougainvillea bracts and in the USA Megachile umatillensis uses evening primrose petals, how pretty!

There are several species in the UK but the most commonly seen are, Megachile centuncularis (the one I am painting), and Megachile willughbiella.

The Slow Megachile Painting Slow decisions… Day one… Tuesday

This particular painting has taken me an agonisingly long time.. mainly because I kept changing my mind. Sometimes I know exactly what I want to do, but now I have to consider the paintings as a set and make sure I get a variety of poses and compositions etc. My very first thumbnails done back in Feb were a good guide but I have already altered one or two.

image

First British Bee Thumbnails

I knew I wanted to include the rose leaves with the cut out circles because Megachile centuncularis is also known as the “rose leaf cutter bee” due to her partiality to roses.
So I made more thumbnails and initially chose to work on one with the bee flying away from the rose, mainly because I really wanted a more front face view.  But, if she were flying away from the leaves, she should really be carrying a piece of leaf.

thumbnails    

I pondered all this, spent half a day going down this route and then I decided against it. The bees carry the leaves clasped between their jaws and held with their legs which does to be honest, look rather strange, especially if this is your first encounter with a leafcutter bee.

So I changed the view to her flying towards the rose in eager anticipation of a bit of leaf chewing…I had tried the wings in different positions too but liked the anticipation of the forward position, they are almost like welcoming open arms.

   

I am a bit sad to lose the engaging front view eye contact .. but it makes more sense.  Also,  as I did with the Leu Gardens exhibition I will be having explanatory notes to accompany the work, so I think I will include a drawing of her carrying the leaf there. But it has taken me a day to get this far.

Slow painting… Day two… Wednesday …

At the side of the board is one of my boxes of bees with a little leafcutter under the magnifying glass. It’s a really pretty bee with such personality. Like all of them they take a full day to draw out and paint. So much work for something so small!

desk and megachile      

Slow drawing…. Day three…  Thursday

I really thought today was going to be easy because all I have to do is draw the rose.. I went and found some rose leaves nearby, looked at my Leu photos for a nice single rose and then just couldn’t decide how to  arrange them together.

I tried what seemed like a million different variations of flower angles and leaf arrangements.. these are just two which I was quite happy with, Up a bit…. down a bit …

   

But  I eventually realised that I was uneasy with the scale.. so enlarged the rose a bit and then felt a lot happier but its now 1.30pm. sigh ..

My biggest problem at this stage is trying to keep everything clean.
With graphite pencils you do have to keep washing your hands and I try to remember  to work with paper under my hand.  Hazards are everywhere and cups of tea are usually balanced precariously next to me!

However it’s almost finished, perhaps I’ll add a couple more leaves at the bottom but it’s 5.30..enough for today or rather for the last 3 days!  I am glad I turned the flower head up, its more optimistic and less watchful on the part of the flower.

While she is turning her head to the sky the little bee can come and help herself to some more leaf curls. Hmm… that smacks a bit of whimsy doesn’t it,  a word I dislike intensely… blame it on hours of solitary confinement:

Little Miss Leafcutter off for some Leafcurls  🙂

leafcutter bee bg

Watercolour and graphite on Arches HP  approx 8 x 8 inches

The Leafcutter Bee: The Can Opener of the Bee World. Megachile sp.

If you happen to notice some beautifully cut, circular holes in your rose leaves you may well have some Megachile bees in your garden.

There will be no great damage to your plants and what some may find unsightly, I think is rather attractive.

Also, when you know that the female Megachile is just using the leaves to wrap her little ones in, you would hardly begrudge her a leaf or two, would you?

To help her this little bee is equipped with very strong chewing mandibles which she uses to bite through the leaves. It only takes one or two seconds for her to complete this operation.

Here is a sequence of photos by different photgraphers from the excellent photographic site Arkive: Images of Life on Earth, and the text is from “Bees of the World” by Christopher O’Toole and Anthony Raw.

Round-notches-cut-from-rose-leaves-by-megachile-leaf-cutter-bees

“Just before the leaf fragment becomes completely detached the female vibrates her wings rapidly so she is already in flight as soon as the leaf is free.
She then flies a short distance and lands on the ground, a stone or a tree trunk while she adjusts her load. If the leaf fragment is longer than broad she uses her feet to fold it lengthways, so she straddles the leaf with its convex surface towards her. She flies back to the nest carrying the leaf in this way.”

 

Megachile-leaf-cutter-bee-transporting-leaf-in-flight

There she makes beautifully crafted overlapping nest pockets, a kind of natural origami pot with which she lines her nest.

She sticks the leaf fragment together by crimping the edges of the leaves so that sap oozes out and this possibly with salivary glue acts as an adhesive.”

Megachile-leaf-cutter-bee-nest-of-sticked-and-rolled-leaves

I am fascinated by the shape. These individual cells must fit into each other so the bee must know to taper them.
Here is a very nice description from an article by Louise Kulzer from the website;

Bugs of the Month” by Scarabs: The Bug Society, here

Actually, it’s a bit more elaborate than just lining the nest burrow. Leaf-cutter bees construct several cells from the leaf pieces they collect. The cells are positioned end to end in a long burrow.
Several circular leaf pieces form the bottom, then oblong pieces are placed along the sides to form a “thimble.” This thimble is then provisioned with nectar and pollen, and an egg is laid in it.

Then the bee cuts more circular pieces to close the cell. Once the cell is closed, the bee starts another cell above the first, until the whole cavity is filled. Like all solitary bees, the female leaves the nest after it is closed. The grubs fend for themselves on the nectar and pollen.

The adult leaf-cutter bee is smaller than a honey bee, dark, often hairy, with a prominent pollen basket below. Females are workaholics, and are a delight to watch because, being so intent on cutting leaves, they usually ignore a nearby observer!
The leaf sections are cut with the mandibles, and the bee forms an arc with her head along the leaf edge to make the circular shape. (They remind me a little of an electric can opener, only with much more personality.)

The facts
CLASS: Insecta
ORDER: Hymenoptera, Bees, wasps, ants and sawflies.
SUPERFAMILY: Apoidea. Bees and some wasps.
FAMILY: Megachilidae
GENUS: Megachile

The Megachilae are a huge genus of bee with well over 500 species. The most important North America species is the Alfalfa leafcutter bee Megachile rotundata which is used for alfalfa pollination.
A monster member of this family is Megachile pluto. A female can reach 1.5 inches long.

Stavenn_Megachile_pluto

photo by Stavenn from Wikipedia here.

My bee is Megachile brevis a delightfully smart and perky little bee. The body shape is unusual in that there is a definite upward tilt rather than the more downward curved body shape of other bees.
These bees, like all of the female Megachile species carry dry pollen under their abdomen in the stiff bristly hairs called the “scopa” which in other bees is located on the legs.
I have Sam Droege and Anna to thank again for their help.

There was only one way I wanted to draw this bee. She had to show her stripes and pointed abdomen and the pollen basket, so a side view to show the tilted body shape too.

megachile sketch

A friend of mine described her yesterday as “very sassy”!

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Bee number 15: The Leafcutter Bee, Megachile brevis


megachile leafcutter bee

Watercolour on Arches HP, Image size 3.5 inches.