Sunday 3 August 2014

Och aye the nooooo: Huge hornets in Scotland? | Bye bye British bees?

Giant versions of species are normally a staple of science fiction movies, be it a megashark, a giant octopus or a crocosaurus. However, an interesting story caught my eye the other day involving the potential sighting of a peculiar large creature.
Megashark attacking the Golden Gate Bridge. 
According to a story in The Independent, a large, deadly hornet may have been spotted in Scotland. And, this blog being what it is, the hornet in question is, of course, an invasive species. So what's actually been going on?

Well, the piece tells the story of workmen in Fife who have reported seeing a creature 'two to three inches long' buzzing around them. Understandably, confronted by this beast, one of the workmen dealt with it using the sophisticated piece of insect removal equipment known as a 'hammer'.
Just your standard piece of apparatus for insect annihilation...
The workmen believe that what they saw was Vespa velutina, or as it is more commonly known, the Asian Hornet.

However, Asian Hornets are only 3cm in size, which is considerably smaller than the dimensions of the bothersome buzzer reported by the Fife workmen.

Given this dimension disparity, and the fact that there have been no cases of Asian Hornets in the UK, it is believed that the workmen actually saw the larger Vespa Crabro, more commonly known as the European Hornet or Horntail.
Queens of Vespa Crabro (right) and the smaller Vespa velutina (left). Source (Monceau et al., 2014)
So, the sighting of Vespa velutina in our lands may well have been a false alarm. However, it is considered a matter of when, not if, the Asian Hornet makes it to Britain. And when it does, it could be an invasive species with a considerable sting in its tail.

Originally from China, the Asian Hornet was accidentally introduced to France in 2004. Since then it has caused the deaths of six people. The population of Asian Hornets has grown rapidly and spread to other European countries including Spain, Portugal and Belgium (Monceau et al., 2014).
Map highlighting the spread of the Asian Hornet from 2004-2010.
Though the deaths of six people is obviously a concern, a larger one may lie in the potential impact that the Asian Hornet could have on Britain's honeybees. Honeybees have been observed to constitute at least oa third of the Hornet's diet and one bee-keeper has reported losing 80% of his hives due to the Asian Hornet (Monceau et al., 2014).

With honeybees already facing a multitude of stresses, the introduction of this invasive to the UK would represent an unwelcome exacerbating factor. So what can be done?

Hello hornet, bye bye bees?
Well, first and foremost it is of utmost importance that the arrival of the Asian Hornet is recognized quickly. Eradication would only be feasible in the earliest stages of its arrival.

Established Hornet's nests are costly and risky to destroy, with the process only deemed a success if every individual is destroyed (Monceau et al., 2014), which itself is hard to actually prove.

A sizable Asian Hornet nest.
Other options include limiting the reproduction of the Hornet's and biological control. However, mating behaviour of the species is poorly understood and biological control using parasites could have negative impacts on other species (Monceau et al., 2014), making both of these suggestions far from ideal.

Clearly, the Asian Hornet could have a significant detrimental impact on Britain's apiculture. If you think you see one,  maybe follow the example from the Fife workmen, grab your nearest hammer and go to town. However, also make sure you report it to the Non Native Species Secretariat!

Over and out

The Invader Inspector