THE DANGERS OF HORNET (AND WASP) TRAPS – by Glyn Davies.
We’ve come to treat wasp traps as almost a vital accessory to any apiary. It’s quite common to find Beekeepers who express their hatred of wasps in very strong terms. Some take pride in killing spring foraging queen wasps claiming to have saved thousands appearing in the autumn and their extreme aggravation for people and bees until the first winter frosts. There is a range of contradictory opinion of course. Valid claims of their ecological importance are emphasised for many important ecological reasons. And the usefulness and positioning of wasp traps is also contentious, but the native status of wasps (for most species anyway) and the European Hornet, is not disputed.
So when the alien bee-predating Vespa velutina threatened, it was a knee jerk reaction to consider trapping around the apiary as an obvious solution. But problems emerged immediately. What bait? Keeping rain out? How and where to hang it? And what about wrongly captured natives? So a trap was designed to hopefully eliminate these concerns. Varied ideas contributed to the trap features and the picture here is typical of the DIY versions that appeared across the country. In February 2017 I led a workshop at the Holsworthy to make up over 30 of similar design. I really thought we had a good plan. But the summer usage of the traps revealed serious flaws and problems, and the confirmation of uselessness, for me, was to hear of the discovery of a Vespa velutina attack just a few miles from Holsworthy.
And just what were the problems and lessons that emerged?
- Carbohydrate or protein? Timing and recipe are not settled; Early and regular replacement of both bait types when they rapidly decomposed was needed.
- Native, beneficial insects were trapped in hundreds, many died.
- Flooding of bait area by rain making it useless.
- Good DIY skills needed for even reasonable trap efficacy and managing practical difficulties of construction.
- Hornets predate hives of bees from late summer but feed on other important insects earlier.
- Queens after hibernation seek carbohydrate early and protein later. When to change over bait?
- First hornet nests are built in low, sheltered sites, later, larger nests are higher in tall trees.
- Monitoring baits can be anywhere not just near apiaries.
- Overwintering queens seek sheltered, dark sites and caravans and motorhomes travelling through France in the Autumn offer plenty of cosy places.
Now these are practical problems. These traps are expected to be common nationwide immediately. The two sightings so far at Tetbury in 2016 and Woolacombe in 2017, over 100 miles apart indicates that the next sighting could be anywhere in UK. So everywhere and everyone has to be prepared. So let’s get real. Beekeepers are the country’s hornet vigilantes.
- We need a simple system to discover the hornet’s presence.
- We need to ensure no harm comes to non-target insects.
- We need to have local expertise in identification.
- We need to have skills to identify the nest location.
- We need to know how to get professional extermination.
These following proposals are based on our own experiences in Devon and discussion with leading Beekeepers from Jersey, already invaded and managing the hornet challenge.
Early in the year, say through March to early April emerging queens need carbohydrates for energy to search for a first nesting spot. It will not be far from where they hibernated. Rich early nectiferous flowers attract them. Jersey folk found Camellias with single-type flowers are favoured. Asian plants of course. Later in the year, May to June, the worker hornets need and collect loads of protein to feed their growing grubs, Apparently the workers get sugars from their maturing carnivorous larvae as a sort of excreted reward and incentive for further protein foraging. So here is a plan of action which can be taken easily all over the country involving beekeepers and non-beekeepers.
March. Set out small dishes of sugary bait where they are easily and regularly observed. Window sill, bird table, garden ornament etc. Observe visitors.
May/June change bait to protein. Eg bits of fish finger or cat food To keep birds away a mesh such as chicken wire will be needed.
If an Asian Hornet is suspected, contact a local coordinator, most likely from the nearby bee club who will have publicised details around the area.
Keep bait topped up. The suspect hornet will return regularly.
The coordinator on arrival will confirm Asian Hornet. Then one has to be stunned or captured and reported to NBU or NNSS. No traps needed, no danger to beneficial insects. The hornet nest will not be going away. No need to rush. Keep bait topped up. Contacted experts will be able to track the hornet flight and the nest will be found and destroyed.
This system will depend on every local bee club training several coordinators and widely publishing contact details.
DON’T PANIC CAPTAIN MANNERING(sic), DON’T PANIC!
A year ago I really believed what we were told about the Asian Hornet. If it’s here, the queens will wake up in the Spring, and search for carbohydrate nourishment immediately, then go searching for prey as a typical carnivore should. Catch’em before they reach the stay-at-home stage and you’ve effectively killed the whole colony of hornets.
Ingenious traps were designed incorporating several great ideas of simplicity and structure to improve their efficacy and convenience. Public and beekeepers’ concerns were raised, many associations organised trap-making sessions to hang them around apiaries to protect our bees from the alien invaders. Hundreds were made and baited with a variety of attractive ingredients.
“Look at the wasps we caught and hornets, (English ones). Dirty Flies too, hundreds of ‘em.
We’ll show ‘em whose in charge. We’ll show ‘em . Don’t panic Captain Mannering(sic). Don’t panic!”……. .And then the problems emerged.
Why is changing your mind considered a sign of weakness? Surely as we learn more, gain experience and understanding, opinions have to be amended. Is it a British trait or just a human one that condemns people who make mistakes. More can be learned from one thing that goes wrong than a hundred that go right.
So let’s take a slow, calm look at the situation. What were the mistakes in the design and use of the traps ? What has been learned in the past year about the Asian Hornet that we didn’t know before? And crucially, are there any weaknesses in the Vespa velutina life history that could be exploited in the battle? Scientifically we don’t know what impact the establishment of will have on our native species of wasps, hornets and other indigenous insect species. As the picture shows there is clear evidence for the harmful effect of bottle traps. There is also anecdotal evidence from France that native butterflies and wasps have shown a recent correlated decline in numbers but this has not been clearly shown as a direct consequence.
The design of the recommended trap seemed to cover everything. It is cheap to make although fiddly with several lengths of wire to be threaded through awkward and not easily aligned holes. A roof to keep rain out although it just runs down the sides to flood the bait unless protected.
The entrance hole in the funnel either kept the queen hornet out if too small but let everything in if larger.
Releasing non-target insects everyday became a tricky chore and likely to be neglected causing death by dangerous trapping. Protein bait rapidly decomposed in spring and summer sunshine. This made maintenance unpleasant and traps only attractive to bluebottles. Then for me, the final worthlessness was running a trap-making workshop in Holsworthy, distributing 20+ extra kits there, North Devon branch running a similar workshop and then Asian Hornets found attacking a hive in October a few miles away.
So what have we learned about V velutina last year?
It only raids hive bees from about August, before then it feeds on a variety of invertebrates especially other insects.
- It probably arrived on a caravan, motor home, car or truck that passed through France late summer and as a mated Queen on arrival in England, selected a cosy spot to hibernate in the vehicle or locally. Where better than Devon or even Tetbury?
- It searches for a good nectar source when first out of hibernation.
- It returns to a food source regularly and frequently once found.
- It’s not aggressive away from the nest.
- It flies fast and as straight as possible from food to nest.
- Diet changes to animal protein as soon as larvae are present.
- The nest is usually just a few hundred meters from the foraging site.
- Workers like to forage on fresh plant sap.
The next arrival of V velutina can be anywhere in UK not necessarily near beehives or previous
Many of these observations have been communicated to us by Jersey Beekeepers who have worked diligently to control the hornet there. So the informed attack on the Asian Hornet we make on the mainland should be revised and for the protection of beneficial and ecologically important insects could be like this system below which is based on the Jersey approach.
- Select about six small plates or dishes.
- Select a covered site such as a bird table, or window sill that can be viewed regularly everyday.
- Decide on a sweet bait for use during March.
- Decide on a meaty bait for use during the rest of the season. This will have to be protected from birds perhaps with chicken wire.
- If a suspicious hornet-like visitor is noticed contact the nearest AHAT.
- Keep the bait topped up. Then your suspicious beast will return regularly.
- Without involving AHAT, take a photo of the insect at the bait; capture it in a clip queen cage or try swatting it, very smartly, with a badminton racquet. The evidence must be sent for official confirmation. AHAT can provide details.
- If not killed or captured or is one of many workers then AHAT must be contacted so that tracking the nest can start.
The extermination of the nest must be done by trained people – Professionals in the early years. This system protects the very important beneficial insects that risk being needlessly killed in thousands by nationwide baited traps searching out optimistically just one or two hornet queens or nests that could be anywhere in UK or even absent.
A Quote from the website ‘Wildlife in France.’ .
“Please don’t use traps as they will also attract and kill
our native species of Hornet and Social Wasps
which are already suffering enough and in decline.”