Asian Hornets – are they on their way here?

We are incredibly proud of our little apiary here at Hunters Lodge.  Our bees are tended to with great love and care.

In turn, they reward us with the most delicious honey.

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Now I say we, but in truth, it’s Eamonn who puts in all the work with the bees.  If he is too busy to attend local beekeeping meetings, he catches up with all the latest “bee talk” through “An Beachaire, The Irish Beekeeper”, a monthly journal issued to members by FIBKA (Federation of Irish Beekeeper’s Associations).  Each month it is packed with news and advice.  The September issue arrived bringing news of the Asian hornet.  Now, I hadn’t heard of this particular hornet, but it is something that every Irish beekeeper needs to become familiar with.

The article was written by Mary Montaut, Hon. Editor of “An Beachaire, The Irish Beekeeper”, and I contacted her for permission to share her article with you.

Even if you are not a beekeeper, you will find this interesting.

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 “The Editor would like to pass on some vital information about the Asian Hornet (Vespa velutina) to all our readers, because this highly predatory insect has the potential to become a serious threat to our own bees.  There is a native hornet in the UK, Vespa crabo, but Ireland has no native hornets, though we do have plenty of its close relative, the wasps (Vespula spp.).  The Asian Hornet is an unlucky import into Europe, where it arrived accidentally along with goods from China in 2004.  It was first spotted in France, and has since spread to Spain, Portugal and Italy, and there are some recent reports of possible sightings in Belgium.  Its arrival in the UK is considered to be very likely, and it would only be a short hop over to Ireland.

The Asian Hornet is a very distinctive-looking insect.  Whereas the European hornets have yellow bands on their abdomen (like big wasps), the Asian Hornets are mostly dark brown or blackish with just one orange or yellow band near the stinger.  The queens are about 30mm long, and the workers about 25mm, and their legs are yellow.  It is sometimes known as the Yellow-Legged Hornet.  In the UK, beekeepers are requested to report any suspected sightings of this insect.  I feel that it would be an excellent precaution for us as well, to report any such sightings to the Dept. of Agriculture and also to Biodiversity Ireland.  It is likely that beekeepers would be among the first to notice, if this invasive insect does unluckily arrive here.

Asian Hornets have already devastated honey bee colonies on the continent.  They attack the colony by first picking off individual bees as they return to the hive.  The bees may decide that discretion is the better part of valour, and remain within the hive instead of foraging.  When the colony is weakened, the group of  hornets will attack and devour the bees and the remaining stores.   Asian Honey Bees (Apis cerana) have evolved alongside the hornets, and they defend themselves in two ways: firstly by evading the hunting hornets by extremely rapid flight into and out of the hive; and secondly the guard bees are able to ‘ball’ the hornet if it enters the hive, and suffocate it.  They also perform a ‘shimmering’ exercise with their wings to warn the colony.  But European honey bees have no such defences, and tend to slow down when they spot a predatory hornet prowling near the colony, making them easy prey.   There is some evidence from beekeepers in Japan who have Apis mellifera colonies that their colonies are learning to ‘ball’ the invaders, creating intense heat within the ball of bees and killing the hornet this way.  We are familiar enough with our bees’ reaction to an alien queen being to ‘ball’ her – this new defensive behaviour seems to be a development from that.  But so far, bees in Europe have not learned to defend themselves against this new threat.

A trap called the ApiShield is being marketed by Vita (Europe) which should be most helpful if this invader arrives here.  It is a modified base for the hive, with a decoy entrance into a trap, as well as a normal entry for the bees.  It works because the invaders choose to enter by the decoy entry rather than face the guard bees.  Apparently it is also useful to deal with wasps, wax moths and robber bees.  It works by  ‘teaching’ the colony to use the front entry, and then opening decoy entries at the side which fool the predators and trap them below the real floor.  It seems most ingenious.

I expect that you are placing wasp traps around your hives to protect them.  The simplest trap is made by cutting off the top quarter of a plastic drink bottle, inserting it back into the body of the bottle upside down to form a funnel into the lower section, and supplying the trap thus formed with water and jam, to lure the wasps to their watery fate.  Although at this time of the year, beekeepers are rightly anxious to protect their colonies from wasps (Vespula vulgaris) which prey on them, it is important for us to realize that wasps serve many useful functions in the environment.  The Editor is particularly grateful to Tomas Murray of Biodiversity Ireland for the following notes about wasps:

‘With regards the role of the Vespinae or social wasps in Irish insect ecology, they’re typically seen as pests but are really fantastic pest controllers.  It is estimated that just one species, Vespula vulgaris, consumes between 2-91 million kg of insects per year (their populations vary a lot across years), that’s the equivalent weight of 1-16% of the human population on the island of Ireland.  Ireland has 6 species of social wasp, so the potential insect biomass consumed per year by this group alone is staggering.  Their prey typically includes flies, moth and butterfly larvae, and spiders, strongly suggesting that they play a crucial role in structuring invertebrate communities as a top predators across Ireland.  It is only at the end of their colony’s lifecycle when the number of wasp larvae, and the sweet exudate they produce, declines that they become a pest to the general public and beekeepers alike.

However, given their importance, we still know very little about the distribution and abundance of social wasps in Ireland. Therefore, a national, citizen-science led monitoring scheme will develop a baseline for their populations sizes and communities across Ireland.  An added impetus to developing a monitoring scheme is the imminent threat of an invasive species, the Asian Hornet Vespa velutina. The Hornet originally arrived in 2004 near Agen in France and, as of last year, has now spread to Le Harve (750 km north), with reports of nests being destroyed in Spain (2011), Portugal (2012) and Italy (2013), and male hornets observed flying in Belgium (2011, 2012).  Initial reports of its foraging behaviour indicate that one- to two-thirds of it diet consists of bees, indicating it is a more voracious predator of honeybees compared to the native European Hornet Vespa crabro (which is not in Ireland).  Should this invasive hornet enter and establish in Ireland, it would have potentially dramatic consequences for changing the structure of our insect communities and adding further negative pressure on our already beleaguered honeybee populations.’

Whether you’re a beekeeper or not, it’s good to be aware and as soon as I get my hands on a picture of an Asian hornet, I will share it with you.

Back soon

Fiona

* Many thanks to Mary Montaut of “An Beachaire, The Irish Beekeeper” for her assistance with this article.  If you are interested in learning more about beekeeping, visit irishbeekeeping.ie

You’ll find my take on Irish Apples in the Oct/Nov edition of Irish Country magazine.

For more of my “back to basics” tips, check out the current edition of the UK’s Home Farmer 

I’m delighted to be MC for the night in Ballon, Co Carlow on October 10th for their harvest food festival – do come say hello!

“Food from an Irish Garden” is available in bookstores nationwide.

3 thoughts on “Asian Hornets – are they on their way here?

  1. Our 7yo daughter loves thick honey and because of your blog post, she is considering bee-keeping as a way of making her own jars of honey. Thanks!

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