A hornet in the garden

Four days ago in the meadow I spotted something large and yellow out of the corner of my eye but it flew off before I could see what it was.  Armed with a camera I stood waiting for another view and after a few further brief glimpses I got a couple of blurry photos to confirm it was a European Hornet queen (Vespa crabro).

The hornet was flying around the trees, looking as though it was searching for a nest site rather than hunting.  Yesterday I was standing by the pond in the meadow when the hornet flew down for a drink.  One thing I have learnt is always to carry a camera in the meadow so this time I was ready for it.

An hour later it was back for more water.  Hornets collect water to use with chewed dead wood to make the papier-mâché they use to build their nests so I am very hopeful this one has a nest nearby, perhaps even in the garden.  If it sticks around you can expect more photos here.

Hornets are present in most of England and Wales but are rare in the north.  I was pleased to find that this is the most northerly confirmed British record.  This image shows records in iRecord with mine in red.

I am about 2km north of Gosforth Nature Reserve where hornets were present in 2018 but haven't been seen since early the following year.  Here are a couple of my favourite photos from then.

A new generation

This was a most exciting find.  At the City Nature Challenge Bioblitz at Gosforth Park Nature Reserve on Saturday our visitors were encouraged to find things for identification and recording and one little girl found this!

It is a queen hornet (Vespa crabro) just emerging from hibernation.  Last year was the first time hornets have ever been documented this far north, almost 100km north of the previous limit of their range.  This is the first evidence that any has survived and shows there is a good chance they may establish locally.  We now have to hope this queen will successfully found a new nest and that there are others.  To encourage them we have built and installed a hornet nest box in the reserve so let's hope one of them likes it and moves in.

If we do see more you can be sure to read about it here.

End of year favourites - Hymenoptera

This is my last post of the year and the last review of the year.  The warm summer we had was a good one for bees and wasps and was especially memorable for the appearance of European hornets in our local nature reserve.  The image above has been the cover photo of the UK Bees, Wasps and Ants Facebook page for the past couple of months.

A new bumblebee that was high on my wish list was the bilberry bumblebee (Bombus monticola).  I found this one (♀) in Harwood Forest.

Emerging from my bee house on exactly the same date as last year (4th May), a red mason bee (Osmia bicornis ♂).

A nice surprise at my local pond, a tawny mining bee (Andrena fulva ♀).

A perennial favourite, the hairy-footed flower bee (Anthophora plumipes ♂).

I found an aggregation of orange-tailed mining bees (Andrena haemorrhoa) in the local nature reserve.  This is a female.

And chocolate mining bees (Andrena scotica ♀) in the house!

This cuckoo bee, Nomada marshamella, is a cleptoparasite of Andrena scotica but was seen at Ovingham, not at home.

A new bee in the garden, a male blue mason bee (Osmia caerulescens).  I haven't yet seen a female - perhaps next year.

And the highlight of the year - the European hornets (Vespa crabro) in my local nature reserve.  I do hope they return next year.

The outliers

European hornets are long established in the south of the country and, like many insects, their range is spreading northwards.  The 10 km blue squares on this map from iRecord show all UK records for Vespa crabro this year.  The wiggly blue box delineates our local vice-county, South Northumberland (VC 67).  Note that the rectangular blue symbols in Scotland and Ireland are motorway numbers - they have no hornets.

Our hornets are shown in two blue boxes at the top because data were entered by two people (the other being the vice-county recorder for moths) at points 50 m apart in the reserve and, by chance, the two points are in different 1 km squares which are in different 10 km squares!  Hence two blue boxes.

As you can see from the first map, our hornets are way outside the previous recorded range (90 km from the nearest data point in Yorkshire).  When I entered the record of our local hornets, with a photo, I got this response, although the record has since been accepted.

It is intriguing to consider where the hornets came from.  It is possible that they have been around for a while and no-one noticed although that seems unlikely as they are pretty obvious, being large, yellow and noisy.  iRecord data go back 10 years and contain only one other record for the county, 40 km farther north in Harwood Forest in 2015.  That record has no supporting photo and from the details provided it seems unlikely to be correct.

A second possibility is that the foundress queen for "our" nest flew the 90 km from Yorkshire, possibly wind-assisted.  I don't know how far European hornet queens are prepared to fly but I have read that Asian hornet queens (Vespa velutina) in France can spread at up to 60 km a year.

The third possibility is that the queen that founded our local colony hitched a lift during hibernation.  There is a large bakery and food factory just across the road which presumably imports a lot of material on pallets, etc.  We know that the Asian hornet arrived in France from China in a consignment of pottery in 2003 or 2004 so maybe our European hornet hitchhiked from the south in a similar way.

If these hornets are true outliers there is some concern about how they might fare in subsequent years.  Depending on how the queen of this colony was mated (and most queens mate only once) there is a fairly high chance that most or all of her offspring are full siblings. This means that matings of the males and new queens raise the prospect of inbreeding weakening later generations. Male hornets, like all other male wasps and bees, are haploid, that is they have a single set of chromosomes.  All females (workers and queens) are diploid, with a double set.  If my calculations are correct, theoretically sibling mating will lead to 25% of the next generation having two identical copies of the sex-determination gene so rather than being female workers they become diploid males, meaning that they are a drain on resources, and thus weaken the colony without contributing to the genetic line or the workforce.  The proportion of diploid males increases to 33% in each of the following two generations (the maths is quite complicated so I haven't gone any further than that).  In theory this would be bad news but the European population of Asian hornets is all thought to have come from a single foundress queen and it doesn't seem to have done them much harm, even though they do produce quite a lot of diploid males.

Up close and personal

The hornets are still around but in smaller numbers.  I now think the nest must be a bit farther away in the woods than we first thought.  The most hornets visiting the maple syrup at one time was eight, whereas there are probably a couple of hundred in the nest.

We have still only seen two males but I think some of the larger females must be new queens.  These are probably all workers.

Workers were still hunting just over a week ago, which meant they were still feeding larvae, and as the pupation time is around 15 days new hornets will still be emerging next week.  However, if they don't visit the maple syrup or the ivy flowers in the warden's garden it will be very difficult to tell what is going on.  Let's hope we see a few more.

At last

At last.  This is what we have been waiting for for the past couple of weeks -  a male hornet.  This one turned up to the maple syrup feeder - the first male I have ever seen.

He has very long dark antennae.  Males have 13 segments in their antennae whereas females have 12 but these look more than a twelfth longer.  You can also see he has seven abdominal segments (females have six).

I first saw him crawling around under the dish below the feeder and it seemed take him a long time to work out where the food was - the females take about five seconds!

This male was wary of approaching the maple syrup when workers were present.  Several times they drove him off, perhaps a normal reaction to encourage males to disperse to other colonies.

Down at the water hole

I hope you don't mind some more hornet photos.  You may have guessed that these are my favourite insects at present and they are such fun to watch. Their colours are amazing and I love the slightly clumsy noisy way they fly.  If I am in the way as they approach they fly around me trying to judge if I could be something to eat or if I might eat them.  When they decide on neither of these they whizz down to the food.  I have used a piece of stone this time to give a more appealing background than the plastic dish.

When they line up like this they remind me of lions at a water hole - perhaps lions wearing dark glasses.

The key again is maple syrup.

These flies were chancing their luck but they stayed just out of reach and they have faster reflexes than the hornets.