Hive Mind: threats to honey bees

The hall was packed. The March evening meeting of Cardiff, Vale and Valleys Beekeepers Association was listening carefully to Edmund, a Seasonal Bee Inspector (yes it’s a real thing) as he briefed us on the Asian hornet, how to identify the blighter and how the National Bee Unit responds to positive reports of sightings. After answering numerous questions it was over to me. I thanked him for his talk and explained the next part of the session: making monitoring traps.

There was silence.

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What are the threats to honey bees?

Beekeepers learn about these so we can best help our bees should the need arise; the threats (mostly) fall into three types:

1. Pests
2. Diseases
3. Pests and diseases that could arrive here

Now I’m not going to give you chapter and verse on all of these and nor is this intended as a definitive list: I realise I have a range of readers so will highlight a few for new beekeepers and won’t go into the gory details for non-beekeepers. There’ll be plenty of links if you want to know more and the National Bee Unit has the full list. If you don’t feel like you need to know all of this right now just skip onto the last section.

There are other threats such as climate change, weather, pesticide use and availability of forage; I’ll write about these another time.

 

Pests

Asian Hornet

 

 

 

First picture: Asian hornet, Gilles San Martin/Flickr, CC BY-SA 2.0.
Second picture: European hornet, PiccoloNamek/Wikipedia, CC BY-SA 3.0.

This aforementioned blighter (first picture) has only recently reached France, with incursions into the UK in the last few years. It “hawks” (hovers) in front of the hive picking off the incoming bees, dismembering them and taking the abdomen back to the nest to feed the larvae. Nice. It can decimate colonies and is likely to become a big problem if it establishes here. Beekeepers and the public alike can have a role in identifying and reporting it but please don’t confuse it with our beautiful native European hornet (right picture). Basically if you see one and think “Arrgh! That’s a *&^%?@# HUGE wasp!” it’s probably our native hornet and not an issue.

Varroa mite and Deformed Wing Virus

 

Left: Varroa mites, US Department of Agriculture/Flickr, CC BY-2.0.
Right: Varroa on the back of a honey bee for scale, 12019/Pixabay, CC0.

The dramatically named Varroa destructor is a natural parasite of the Asian honey bee, who has developed defences against it. It affects the brood and adult bees, needing the brood to complete its lifecycle. Varroa infestations are linked to higher incidences of viruses, particularly Deformed Wing Virus,  weakening the colony until it dies.

More nasties

Wax moths and wasps may also cause issues although the colonies can recover if the problem is spotted in time.

 

Diseases

Brood diseases

European and American foulbrood are both notifiable diseases: you must tell the Bee Inspectors. They can help with European foulbrood and a colony may recover but unfortunately the only remedy for American foulbrood is destruction to save other bees in the area. Support from the Bee Inspectors when notifiable diseases are in the area and useful husbandry alerts are two important reasons for beekeepers to register their hives on BeeBase.

Sacbrood and chalkbrood affect the larvae, causing them to die and look like they’re in a sack or been turned to chalk respectively. They can indicate other problems such as a queen who’s running out of sperm.

Adult bee diseases

Nosema is bee dysentery caused by fungi. Often happens in the spring if the bees are stuck in the hive due to bad weather. Acarine are tiny mites that live in the trachea (breathing tubes); the adult bees die off so there aren’t enough to look after the brood.

 

Pests and diseases on the horizon

Small hive beetle is, funnily enough, a small beetle that lives in a hive. Unfortunately it eats everything in a hive bar the frames and the adult bees and will destroy the colony. Currently it’s got as far as Italy. Tropilaelaps is such a lovely word (trop-ee-lay-laps) for a little bugger, a mite that feeds on the brood.

 

A false sense of security

We are an island nation and subconsciously think our encircling seas will protect us from many things, including invading pests and diseases of honey bees. Unfortunately the opposite is true as so many of our goods are imported there are many potential entry points to the UK; factor in the tourist industry and the international trade in honey bees and we have a serious problem. It’s simply not feasible or cheap to check all incoming consignments for threats, particularly when you think about having to look for threats to other species too (including us). Obviously the answer isn’t to stop all tourism and imports so what can we do?

The Sentinel Apiary network

This is a network of apiaries (pdf) across England and Wales near entry points such as ports, airports and lorry depots. They are managed in such a way that the beekeepers look for any incoming problems: it’s an early warning system.

How can non-beekeepers help?

Planting. It sounds trite but the best chance we can give all pollinators is to make sure they’re healthy by growing plants that provide a variety of food sources throughout the year.

Vigilance. Obviously non-beekeepers can’t help check for bee diseases but they can and do play an important role in spotting the Asian hornet — the latest incursion was identified and reported by a member of the public.

 

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For about five seconds I wondered if we’d made a terrible mistake. A member suggested this session and the Committee thought it was a great idea, providing the instructions and materials to build the traps — after all it benefits all members to know as soon as possible when this blighter arrives in the area. Suddenly the buzz of conversation started, the hall was full of movement, and it all turned a bit Blue Peter. I was hugely relieved, proud and impressed at the way everyone piled in and helped each other; it went down so well it’ll probably become an annual feature of our calendar. Though it’s such a shame we need to do it.

 

What the bees taught me this time

• Know what healthy bees and brood look like, then you can identify when something isn’t right.
• Reminded me what diseases affect honey bees, what causes them and what to do about them.
• Reminded me how important it is to assess varroa levels and treat if necessary.

 

Cover photo: Asian hornet, Gilles San Martin/Flickr, CC BY-SA 2.0.