A good spring for Osmia cornuta

A good spring for Osmia cornuta

My bee houses have been rewarding me with lots of activity from the Osmia cornuta in the past weeks.  I’m sure they don’t need any help to find hollow nesting places but when they choose my hollow bamboo canes or drilled-out wood I have the pleasure of watching their antics.

The first I know that some bees have hatched is the frantic activity of the males.  This 17 second video gives you an idea of what it looks like.

I admire the tenacity of the males who guard the holes against all comers.  You can get the idea in this 16 second video.

The male can be easily recognised by the little tuft of white hair on his head.  They are around several weeks before the females eventually hatch and then the excitement really mounts.

The mating is not an elegant affair and this pair managed to get stuck in the tube in a sort of impasse where neither was prepared to cede defeat.

I noticed this mating pair under the box and I was surprised by the females stoic non-resistance.  That was until I saw the photograph on the computer and noticed that the male had a firm grip on her wings and back legs.

The male eventually decided to dismount and release her.

The female is a very attractive bee and is larger than the male, which is not uncommon in bees.  She lays her eggs in hollow stems or crevices and supplies the future larvae with pollen for nourishment.  She pushes the pollen firmly in place with the help of two little horns on her head.

The horns are under the antennae and as the horns are black they are difficult to see amongst the black hairs of her head.  They are best seen in a photograph.

Once the females have emerged they begin their frantic search for the perfect hole.  Despite the abundance of choice from our point of view the females have a need to explore.

Eventually one will meet her high requirements and the egg laying and pollen collection will begin.

Pollen collecting is a serious business even if putting it in place can get a bit messy.

Isn’t nature wonderful ???

Isn’t nature wonderful ???

O.cornuta emerges 19.3.15

The first male Osmia cornuta emerged on the 19 March.  Since then he has had to put up with dull, rainy days and colder than normal temperatures.  I know that the females emerge a few weeks later but he seems completely unaware of this and faithfully visits the holes where I presume he can smell the females, still comfortably tucked up in their cocoons.

IMG_8809.male O.cornuta resting (1)

The males also play out the waiting game sitting in any of the empty holes of the bee hotel, hoping for the sun to come out or better still for the females to emerge.

Anthophora aestivalis...

It’s not just the Osmia males that are in waiting but the Anthophora are waiting too.  (I think this may be an A. aestivalis because I’ve seen its legs and it is not a plumipes.)

2 male o. cornuta (1)

But with all that waiting I think some of them must get a bit confused.

2 male o. cornuta (2)

The male in the hole is desperately trying to explain he is not a female.

2 male o. cornuta (3)

Giving up in desperation he retreats.

2 male o. cornuta (4)

Then gathers his strength to be more assertive and push his way past.

O.cornuta female

Strangely, while all this, “Shuff off, I’m not a female” was going on, I noticed a black head emerging slowly from a hole not far beneath them.  It did make me wonder that if I had noticed and they had been waiting for it to happen for two weeks that they might have been a bit quicker on the uptake.

O.cornuta fem with male

Eventually, without me having to shout, “She’s behind you!”, one of them spotted her.

O.cornuta female emerges

The first Osmia cornuta female of the season emerged!

O.cornuta mating with 3

Having had two weeks to prepare for the big event, I was a bit disappointed with what followed.  I just couldn’t see this position as efficient for increasing the population of solitary bees.  They tried the threesome, never the less, until the top one gave up.

O.cornuta male waiting on side lines

The second male moved off to watch the proceedings from the side lines.

O.cornuta getting suck in the hole

I felt the female was getting pretty fed up and then she made a clever manoeuvre towards a free hole.

O.cornuta getting suck in the hole (1)

This did not deter the determined male who hung on regardless.

O.cornuta getting suck in the hole (2)

The female managed to squash both of them into a stalemate, whereupon the male gave up.

O.cornuta female shakes free

Having shaken off her admirer the female emerged onto the surface of the log to take stock of her position.

O.cornuta female warns off male

A male tried to take advantage of her but was warned off with a defensive position and mandibles wide open in warning.

O.cornuta female grooms

With a few butt wiggles and a quick groom the female took off.  She will soon enough be mated and I am sure return to start her own nests.

The males that I have seen patrolling the bee hotel with impatience will have to get their technique improved if they hope to pass their genes to the future generation.  So far I would rate them at 10/10 for winter survival, spring survival and persistence but they are going to have to do better at their next attempt at copulating.