Blog – bees, beekeeping & other sticky subjects

Interview with a varroa mite

The varroa mite (Varroa destructor) is one of the greatest threats to honey bees and has caused colony losses across almost the entire world. Small and secretive, it hides on bees and in brood cells, mostly out of sight of the beekeeper. To control the mite, miticides have been used since the earliest days of its discovery, but the mite fights back.

Gabrielle Almecija of APINOV (Vita’s partner in France) and IRBI, University of Tours, France asked a varroa mite how they do it.
Here are the mite’s answers in an article from BeeCraft magazine.

The continuing effectivess of Apistan

Beekeepers often ask how effective Apistan is in combatting varroa a few decades after its introduction. The short answer is that it is still a very effective product in most areas and should continue to be so for a long time if it is used correctly.  Here’s a longer answer…

IPM is the key

To inhibit the development of varroa resistance to Apistan, the product should be used only once every 3 – 5 years and should be alternated with other products. This strategy of product rotation (Integrated Pest Management – IPM) has been promoted by Vita Bee Health for more than 20 years. It aids the control of mites and prolongs the life of the limited number of approved medications for varroa control.

Studies show continuing effectiveness

The results of independent and rigorous efficacy studies (summarised below) show that where product rotation is followed, Apistan efficacy can remain almost as high now as when the product was first launched, over 30 years ago. 

Summary of Recent Independent Efficacy Studies

Apistan: 92% efficacy (2020, FNOSAD*, France)

Apistan: 94.90% efficacy (2019, Veterinary Bee Inspector, Spain)

Apistan: 94% efficacy (2019, FNOSAD*, France)

Apistan, field study: 84% efficacy (c.f. Apiguard: 86%; Apivar: 79%; HopGuard: 64%) (Insects, 2018)

Apistan, lab study: 95.72% Varroa mortality (Insects, 2018)

Apistan: 96.92% efficacy (2018, Veterinary Bee Inspector, Spain)

Apistan: 89% efficacy (2018, FNOSAD*, France)

Apistan: 95.22% efficacy (2017, FNOSAD*, France)

* The National Federation of Departmental Apicultural Health Organizations

Vita’s ongoing monitoring

A technical programme of research and monitoring of varroa mite resistance to pyrethroids in general, including tau-fluvalinate and flumethrin (the active ingredient of Bayvarol), was set up and operated by Vita in Europe since the 1990s. We continue unofficial testing performed by beekeepers in different parts of the UK and elsewhere and results indicate that very many colonies have mite populations that can be controlled with Apistan.

How you can check that Apistan is still effective

As with any varroa-control product, we recommend monitoring mite levels before, during and after treatment. Apistan is a fast-acting miticide so comparison of daily mite fall before and 24 hours after inserting the strips into the colony will give an immediate indication of the effectiveness of the product.

Higher or lower?

Vita’s blogger has been out again with a radio-controlled (UAV) drone chasing honey bee drone congregation areas (DCAs)

At the site of the first documented DCA (by Gilbert White on Selborne Common, Hampshire), I’ve been successful in finding DSCAs just 4m or 5m above the ground but have often wondered what is happening higher up. So, a UAV drone acquisition seemed the way to provide the answer. And it did.

At the end of the honey bee drone season, a few drones showed up at 10m. Not very convincing, but it was the end of the season. The drone flew higher – up to 40m – but nothing could be seen from the ground, until the video was downloaded and there they were! Not many, but clearly some. How many might there be up there at the height of the honey bee drone season?

And are there really two distinct flying levels? Some research has said that Carniolan and Italian bees do indeed mate a at different heights. Roll on next season.

Where did the DCA go? Upwards!

Those who have followed the drone congregation area (DCA) hunts of Vita’s blogger over the past few years may have been surprised that the DCAs can be found at only five metres above ground. But this year it hasn’t been so easy to find them with a lure on an extendable fishing rod. Where are the drones congregating hoping to mate with the queen?

Vita’s blogger takes up the story:

On several occasions, the drones did not appear at the five-metre-high lure on days that appeared suitable. I tended to blame the lack of breeze/thermal which is a crucial element, probably because it helps the drones in the precision flying necessary to mate on the wing with a queen. Perhaps the hotter temperatures were having an effect. But I wasn’t convinced. Listening very carefully, it was possible to imagine that there were drones around, perhaps higher up.

Raising the lure higher above the ground poses difficulties of course. But then there are those newly available and affordable remote-control drones.

So, having had an unsuccessful search at one site, I returned armed with extendable fishing rod and radio-controlled drone.

The fishing rod eventually attracted two drones — but on the same site a couple of weeks ago it had attracted fifty or more. So the lure went on the radio-controlled drone and this is what I saw:

From queenless to queenright

How quickly bees change their behaviour in the presence of royalty. Vita’s blogger videos the reaction.