Which varroa treatment is best?

Which varroa treatment is best?

Which one should you use?

Why do you need to use several types?

How do they work anyway?

Will mites become resistant to them?

In this article scientist Dr Pablo German outlines the science-y stuff around how various varroa treatments work, and how likely mites are to becoming resistant to each one.

If you need a quick read, here is my non-science-y summary version first (caveat: always refer to the real deal for the total truth, this is just my layman's version!)

Varroa treatments

Apistan and Bayvarol - works on the nervous system of the mites, quick acting, but mites develop resistance.

Apivar - works on the stress response of mites, slower acting than the previous, but mites develop resistance, although less than above.

Thymol - works in a few different ways at the same time, not all of which are fully understood, and therefore unlikely for mites to develop resistance, but not impossible.

Formic Acid - works in a few ways including on the mitrochondria of mites, and unlikely for mites to develop resistance.

Oxalic Acid - works by direct contact with the mites in ways that aren't entirely clear, and unlikely for mites to develop resistance.

Sugar Dusting - works physically, not very effective, no resistance likely.

Oil Fogging - only affects mites on bees and probably works physically, needs to be applied often, no resistance likely.

So, the short answer is - you need several different types of treatments to deal to varroa effectively.

Here's the full article:


This article was published in The New Zealand Beekeeper, May 2017, Volume 25, number 4.

VARROA TREATMENTS: MODE OF ACTION AND RESISTANCE

Dr Pablo German, Chief Technical Officer, Pheromite
E-mail: pablo.german@pheromite.com

How do the different varroa treatments kill the mites? Why do they kill the mites and do not kill the bees? Can mites become resistant to a particular treatment? Do we care about answering all these questions?

Most beekeepers do care for several reasons. First, we have the natural curiosity of wanting to understand how things work. Second, the more we know about our varroa mite enemy and the weapons we use, the better we will be able to fight against it. Third, we want to understand what secondary effects the treatments may have on the bees. Finally, the mode of action can give clues about the ability of the mites to develop resistance against the treatments.

In spite of the importance of this topic, there are no good summaries on how different treatments affect the mites. There are also unsupported opinions circulating on the Internet.

In this article, I review the scientific literature and summarise the mode of action of different varroa treatments as the knowledge currently stands. Some of the treatments act as the chemicals are absorbed within the body of the mite, others have direct physical effects upon contact, and others stimulate defensive behaviours from the bees.

Tau-fluvalinate/flumethrin

The synthetic chemicals tau-fluvalinate and flumethrin (Apistan® and Bayvarol®) belong to the family of pyrethroids that includes a large number of insecticides used domestically and in agriculture.

Figure 1. Tau-fluvalinate.

Figure 2. Flumethrin.

They work by producing an over-excitation of the nervous system of the mite. In particular, they bind to the voltage-gated sodium channel, present on the membrane of neurons. The inability of the channel to close and reset the neuron to the resting state leads to paralysis and death. Imagine if all your muscles contracted at the same time: you wouldn’t be able to move and breathe.

The reason why tau-fluvalinate and flumethrin are such powerful weapons against varroa is that these compounds have a high affinityfor the varroa mite voltage-gated sodium channel. Interestingly, a recent study reported that tau-fluvalinate has even higher affinity for the honey bee voltage-gated sodium channel. The established safety profile of flumethrin in bees suggests that the bees have detoxification mechanisms that prevent the harmful effects. The high affinity for one single target makes tau-fluvalinate and flumethrin very effective at killing the mite, while at the same time being relatively safe for humans.

Unfortunately, this high affinity for one single target also enables mites to become resistant to tau-fluvalinate and flumethrin with a single DNA mutation in the voltage-gated sodium channel. Random mutations occur all the time, so one single DNA mutation in one gene is an event likely to occur when thousands of mites are breeding in one single beehive.

In the presence of tau-fluvalinate and flumethrin, only mites with specific mutations in the voltage-gated sodium channel are able to survive and continue reproducing. The relatively high likelihood of a single mutation in a single gene to occur, explains why resistance to tau-fluvalinate and flumethrin has been broadly reported around the world. In fact, several single mutations in the voltage-gated sodium channel have been identified that produce tau-fluvalinate- and flumethrin-resistant varroa mites.

Amitraz

The synthetic chemical widely used for treating varroa mites is the contact pesticide amitraz (Apivar®).

Figure 3. Amitraz.

The evidence of the mode of action of amitraz on varroa mites comes from insects and other mites and points to effects on octopamine receptors. The role of octopamine in insects and mites is similar to the role of noradrenaline in humans, which is to trigger the fight-or-flight response. When you are startled by something, your body releases noradrenaline, which binds to the noradrenaline receptor present in tissues and organs throughout your body. Your heart pumps faster, your muscles release quick sources of energy, and you get ready to fight or flee.

A similar stress response occurs in insects and mites when octopamine is released, which binds to the octopamine receptors. Amitraz seems to act by binding to the octopamine receptor(s), which leads to an acute stress response with different effects in insects and mites.

Most beekeepers have noticed that amitraz is slower at killing mites than flumethrin, for example. The reason for this seems to be that by causing this stress response, the mite does not die immediately but its behaviour is completely altered, which leads to death later on. Amitraz is said to act by sub-lethal effects rather than by lethal effects. Humans, and in fact all vertebrates, do not have octopamine receptors, which is the reason why amitraz is relatively safe for humans.

The relatively slow and low onset of varroa mite resistance to amitraz—when compared to resistance to flumethrin for example— seems to indicate that amitraz acts on more targets than just one type of octopamine receptor. Indeed, resistance to amitraz has been reported in fewer cases than the previous two miticides, and studies have shown that the level of resistance is lower as well (the dose of amitraz needed to kill amitraz-resistant mites is not that much higher). In fact, amitraz is still the most effective miticide used in the USA, despite resistance having been reported two decades ago. This seems to point to the fact that one single mutation in one gene is not enough to provide resistance. Although point mutations in amitraz-resistant organisms have been identified, evidence from a cattle tick indicates that resistance to amitraz occurs both by mutations in the octopamine receptor and enhanced metabolism in getting rid of amitraz. In spite of the lower resistance to amitraz by the varroa mite, alternating amitraz with other treatments is still necessary.

Thymol

So far we have only talked about synthetic chemicals. Other chemicals present in nature are known as ‘organic’. Plants, in particular, constantly have to evolve ways to survive against pests. Hence, it is not surprising that several chemicals from plants have insecticide and miticide effects. In contrast with synthetic chemicals that are generally designed against one particular target, plants have to fight against many different pests at the same time. This makes their chemicals more broad spectrum, usually affecting several targets. Essential oils have been shown to have insecticidal effects and thymol, derived from thyme, is most commonly used against the varroa mite. As with previous treatments, most of what we know about how thymol works comes from evidence on insects.

Figure 4. Thymol.

Similar to amitraz, some essential oils also appear to have neurotoxic effects by binding and affecting the function of octopamine receptors. In addition, thymol binds to tyramine receptors, which are related to the octopamine receptors but whose functionis not entirely understood. There is further evidence that thymol affects the function of gamma-aminobutyric acid (GABA) receptors in insects, which are also important for nerve signal transmission.

The presence of multiple targets for thymol makes it more difficult for resistance to occur. In fact, there are no published reports of mite resistance to thymol. This does not mean that resistance to thymol is impossible. One way in which resistance could arise would be by improvement in the detoxification system of the mite. Therefore, it is still best practice to alternate thymol with other treatments.

Formic acid

Other popular miticides used against varroa are organic acids. Formic acid is a volatile acid that works in the hive as a fumigant.

Figure 5. Formic acid.

Initially it was observed that formic acid affects respiration in the mite and this was linked to previous studies suggesting that formic acid inhibits cytochrome c and the electron transport chain in the mitochondria. In addition, formic acid was also suggested to have neurotoxic effects in flies. Later studies seem to suggest that formic acid kills insects, and probably varroa mites, by disrupting the mitochondria in the cells.

What happens when mitochondria in the mite are disrupted? Mitochondria are present within cells and carry out cellular respiration and energy production. When the mitochondria are disrupted, the cells cannot function. This probably leads to neurotoxic effects by disrupting the mitochondria in the neurons and inhibition of respiration. Formic acid seems to cause mitochondria disruption by the physico-chemical effects of low pH.It has been suggested that the bees have higher metabolic and buffering capacity against the acid, which explains why formic acid affects mites more than bees. This mode of action suggests that resistance is not likely to occur as several changes would be needed in the mite. No mite resistance to formic acid has been reported.

Oxalic acid

Oxalic acid is the other common organic acid. As opposed to formic acid that kills mites with the acid vapours, the main way in which oxalic acid kills mites seems to be by direct contact.

Figure 6. Oxalic acid.

There were some reports that oxalic acid may damage the mouthparts of the mite. However, there is no scientific evidence for this and the origin of this concept seems to be a manipulated picture published on the Internet. What we do know is that oxalic acid needs to be in direct contact with the mite and is distributed around the hive via bee-to-bee contact.

Given that oxalic acid has been shown to affect mitochondria in mammals and that mitochondria are sensitive to acids, it is possible that oxalic acid also affects the varroa mite by disrupting or affecting mitochondrial function. In any case, a physico-chemical mode of action would explain why there have been no reports of mites resistant to oxalic acid.

Sugar dusting

There is evidence that sugar dusting with powdered sugar helps increase mite fall and reduce mite numbers. Sugar dusting seems to act in two ways. First, it affects the mite’s ability to cling to bees and they fall off. Second, it stimulates bees grooming themselves and grooming each other, which also produces mites to fall off. Given the physical mode of action, resistance to sugar dusting is not possible. However, sugar dusting has been said to have a small effect in reducing mite levels and may only be useful as a complementary method together with other methods.

Food-grade mineral oil

There is very little literature on the use of food-grade mineral oil (FGMO) for varroa control. However, some beekeepers like to use it either by fogging with thermal insect foggers or with cords. FGMO only affects phoretic mites (mites on bees) and it needs to be applied often to have any effect. Regarding the mode of action, some comments on the Internet point to the oil blocking the pores in the mite’s cuticle and preventing gas exchange, which affects breathing. The cuticle of the mite seems to make it more susceptible than bees. If this physical mode of action is correct, resistance is very unlikely. It is possible that the oil also stimulates bee grooming behaviour.

Conclusion

The mode of action of different varroa treatments has not been studied in detail for most treatments. However, we can still get an idea from studies in insects and other mite species. Different treatments have different modes of action: either chemically after being absorbed, physically by direct contact, or by stimulating defensive behaviours from the bees.

The synthetic chemicals are absorbed by the mite and tend to affect one single protein target, such as the voltage-gated sodium channel (flumethrin and fluvalinate) and octopamine receptors (amitraz). This specificity on single targets makes it highly likely that the mites will develop resistance by mutations in those targets, as has indeed been reported for all of them. In addition, mites can also develop resistance with detoxification enzymes that degrade or get rid of these chemicals from the body.

The organic chemicals act by absorption or direct contact and seem to act by physico- chemical effects on more than one target, making them less specific against varroa mites. This is a logical consequence of the fact that these chemicals are synthesized by plants to fight against different types of insects and pests and not against mites in particular. Indeed, thymol seems to act by affecting octopamine, tyramine, and GABA receptors, formic acid disrupts the mitochondria in cells, perhaps as a consequence of low pH, and oxalic acid may also act by affecting mitochondrial function. The action on more than one target or by physico-chemical effects that disrupt cell structures makes resistance to these treatments less likely. In fact, there are no reports of resistance to these treatments. However, alternation with other treatments is still recommended.

Finally, the less-popular icing sugar and food- grade mineral oil treatments seem to affect the mite by physical effect due to the direct contact and by stimulating bee grooming behaviours. This means that resistance to these treatments is very unlikely to arise.

Table 1. Various treatments, their mode of action and likelihood of varroa resistance.

References

Complete article with references is available on request from the author at pablo.german@pheromite.com.

Organic Varroa treatment for bees

Last weekend we went to the Apiculture NZ Conference.

It was 3 days long and there were so many interesting speakers. They were just about all scientists, who all seem to be just starting on their various research projects. Now, as we all know, science takes a long time, there is no "well that seems about right, let's publish that", and definitely no 'anecdotal evidence'. Or at least the anecdotal evidence might create new areas to look into, but it doesn't form the published results. So it all takes years and years to get a good result. Great stuff that it's happening though.

And, apart from the speakers, we found the conference goers to be super interesting too.

And one great guy we bumped into was Dr Pablo German, who is a scientist who is working on an organic varroa treatment. Doesn't this sound a great idea?! His new (hot off the press) company is here Pheromite.com . Pablo says:

"Beekeepers currently have three types of treatments at their disposal, synthetic chemicals, organic chemicals, and biotechnological methods. However, they all have limitations. Synthetic chemicals are the preferred method for commercial and many non-commercial beekeepers because of their convenience. This has led to the frequent use of these chemicals, often without the use of alternatives, which in turn led to the rise of chemical-resistant mites, in particular in the USA and Europe. "
"Organic chemicals and biotechnological methods are alternatives to synthetic chemicals. Their limitations are that they are very labour-intensive and the results are often inconsistent."
"Pheromite has developed a treatment against the Varroa mite which is organic, works consistently, is long-lasting and easy to set up."

And if you think this is a good idea, well scientists always are on the look out for funding too, so you can find that bit in his web site too. Pheromite.com

We hope he gets adequate funding because if at least one of the chemical treatments for varroa has stopped working in the USA then it might here too any minute. And the traditional organic varroa treatments are very time consuming, so that's OK if you have a few hives, but no good for big commercial operations.

American Foulbrood in NZ

There has been a bit of a problem with an American Foulbrood outbreak lately, in Wellington, caused by the sale of infected boxes (without bees).

American foulbrood (AFB) is a bacterial infection that affects and kills the brood, which is the new bees forming in the brood cells. It has a characteristic foul smell (hence 'foul brood').


Source: wikipedia

New Zealand has strict rules regarding the control and monitoring of AFB, which is part of why all beekeepers need to be registered under the Biosecurity Act, and all their hive locations registered with the Management Agency. All hives need to be inspected by a DECA qualified beekeeper.

Also, an Annual Disease Return needs to be completed by 1 June each year.

If AFB is found, all hives and bees need to be burnt (by NZ regulation), as the spores can last up to 40 years.


Source:By Jrmgkia - Own work, CC BY-SA 3.0,

We take the health of our bees very seriously, and are always on the lookout for signs of ill health, including AFB. AFB is like any other bee problem, it can be avoided with good bee and hive management in most cases.

The official site of the AFB NZ organisation is here if you are interested in all the ins and outs.

How to Kill Paper Wasps

Ha! Easy peasy.

The answer to 'how to kill paper wasps' would appear to be - ring the council.

They are super keen to get rid of anything that is a threat to people, small children, babies, old people etc. ah...not that small children are a threat to people....oh, you know what I mean!

Only thing is, it is helpful to find the nest first. And my wasps are suddenly absent. A bit like when you have toothache for weeks, finally book for the dentist, and the ache mysteriously disappears and you can't remember if it was the right side or the left.

Maybe it just hasn't been sunny enough.

Oh well, no wasps is good right?

Do paper wasps kill bees?

My garden has become infested with paper wasps. They come out in the sun, and love to hang around my clothes line and vegetable garden. On a sunny day I might have 100 or so in close proximity to my clothes hanging activities. Not cool!



There are 2 types of paper wasps, Asian and Australian. Check out this Landcare article for pictures of both.

I've spent ages outside trying to find their nest. Landcare suggests that their nests are small, about the size of a pear. And that they fly no more than 200m. So they must be close.

And AAA pest control Auckland suggests looking at dusk, so you can see them flying in.

Well, I have looked. And looked and looked. I can't see them flying in or out of my place. So that would imply they live in my place. But I can't see them in my place either.

But we've got Vespex, right? That'll deal to them. Except, no.

"Vespex® is specifically designed for wide-area control of Vespula wasp species. In New Zealand, this includes both the common wasp (Vespula vulgaris) and German wasp (V. germanica). These wasps are also known as yellow jackets in some countries."

and that "Paper wasps (Polistes sp.) get the protein they need by hunting for living insects, especially caterpillars, and are not attracted to Vespex®."

But Clemson University says that paper wasps are good for killing garden pests, like caterpillars, of which I have many. Many many. And that paper wasps will die out in the autumn, and the queen will hibernate on her own over winter. Not sure if this applies to our climate, as we don't have hard frosts in Auckland, but fingers crossed.

So maybe I just need to stop hanging my washing out on sunny days?

And keep looking, I think.


And as for 'Do paper wasps kill bees?'. I have no idea. There doesn't seem to be an answer on the interwebs about this. So I am assuming no. Vespula wasps kill bees for sure though.

Wasp Killing with Vespex

A new Insecticide targeting Wasps only

We've all had the experience of ants over-running the kitchen. So you get out the trusty ant bait, the ants carry it back to their nest, and the queen and all the others die.

Well, now there is a wasp bait that does the same - Vespex.

Our surplus boxes are all coming back to the ranch to be cleaned up and re-dipped in oil and then stored for the winter. There is a huge pile stacked up waiting for attention. And boy, do the wasps just love that. All that wax and residue of honey!

So we put out some vespex traps.

And the wasps were immediately into it.

It looked like they were picking up more than their body weight to take back to their nest.

The next day the traps were not entirely empty, but definitely a bit light on the poison,

Note: to be able to get Vespex you need to complete special Vespex training and be registered as an approved user.

Weed killers and bees

How to tell if a weed killer is toxic to bees

Google is a great thing, but also those 2 hours you spend researching something, you never get back, right? I've done quite a bit of research into specific weed killers for our hosts, and thought I would share the better websites that I have found on the way.

Caveat: there isn't AN answer. You can believe what the manufacturers say, or the 'never ever use weedkillers' crowd, or the 'only true if it has been proven by science' crowd - the problem with this last one is that there hasn't to date been a lot of research around all this, bees just got on and did their thing and nobody worried. But now with big problems with Colony Collapse Disorder, especially in the states, more attention is being given to this issue. But any good science takes years, and even then might not produce a definitive answer.

That being said, here is what I came up with:

Say you are going to investigate Conquest.

Its supplied by Nufarm, so if you google it you get the Brochure. Doesn't say what is in it though.



What you want is the label



which lists the active ingredients



picloram and triclopyr in this case.

So let's take Triclopyr - as the butoxyethyl ester:

 (picloram, by the way, was used to make Agent White, and enhanced Agent Orange during the Vietnam War - just saying!)

So on Wikipedia, doesn't say much except that it is "chemically very similar to the herbicide which it generally replaces, 2,4,5-T, which was phased out in the U.S. in the 1970s amid toxicity concerns".

Toxipedia doesn't say much about bees and triclopyr. Although Toxipedia can be quite useful for some chemicals, just not this one. (and Picloram doesn't even get a listing - depends what weed killer you are using as to what information is around).

And then Pesticideinfo which has a whole bunch of science-y information (which both my mother and brother, being chemists, would get all excited about, but the rest of us...not so much).

But down in the Terrestrial Ecotoxicity it does mention bees.



Which might be too tiny to read on this blog, but what it says is it is 'slightly toxic to bees'. And that
"Population-level effects on honeybees may occur even if a pesticide has low acute toxicity. For example, certain pesticides interfere with honeybee reproduction, ability to navigate, or temperature regulation, any of which can have an effect on long-term survival of honeybee colonies. The neonicotinoids, pyrethroids and keto-enol pesticides are some types of pesticides causing one or more of these effects".

So all up, doesn't look dire. Not great either. And I think I would take the bees away before spraying this around. And wait at least the half-life time before bringing the bees back, probably twice the half-life time - which in this case is 39 days see here. So quite a while. (the half life is the time it takes for half the product to be gone, in the soil in this case).

Pesticides that kill bees

Neonicotinoids kill bees

There is a major class of pesticides  - Neonicotinoids - that is known to kill bees. This is a HUGE problem in the United States, where last year beekeepers lost 42% of honey bee colonies, and neonicotinoids are thought to play an important part in that loss.

One pest control company in the states Ortho, has just announced that they are going to "immediately transition away from the use of neonicotinoid-based pesticides".

Read the whole Huffington post article here including some great links to further resources.

And Wikipedia states that "The neonicotinoid family includes acetamiprid, clothianidin, imidacloprid, nitenpyram, nithiazine, thiacloprid and thiamethoxam. Imidacloprid is the most widely used insecticide in the world."

And it also provides this handy list of which products contain them (this is 2011 data)

Name	Company	Products	Turnover in million US$ (2009)
Imidacloprid	Bayer CropScience	Confidor, Admire, Gaucho, Advocate	1,091
Thiamethoxam	Syngenta	Actara, Platinum, Cruiser	627
Clothianidin	Sumitomo Chemical/Bayer CropScience	Poncho, Dantosu, Dantop	439
Acetamiprid	Nippon Soda	Mospilan, Assail, ChipcoTristar	276
Thiacloprid	Bayer CropScience	Calypso	112
Dinotefuran	Mitsui Chemicals	Starkle, Safari, Venom	79
Nitenpyram	Sumitomo Chemical	Capstar, Guardian	8

We do have our own rules governing the use of neonicotinoids, from the EPA, read about them here. But they basically say you're not to spray near beehives or on flowering plants. So they haven't been banned at all.

Neonicotinoids are used to coat some seeds, and these are still sold in NZ.

Two products available in NZ that contain neonicotinoids are "Yates Confidor" and "Yates Rose Gun Advanced".

Also "They are sold here under the common trade names of Cruiser, Gaucho and Poncho, the active neonicotinoid ingredients of which are thiamethoxam, imidacloprid and clothianidin respectively. Gaucho is also used on potatoes, winter squash and pumpkins."

And from Apicare NZ:

Why neonicotinoids are bad for bees

There has been much talk about this group of insecticides globally.  There are now bans and trial bans in place in many areas around the world.  This is not so in New Zealand, so we need to keep a particular eye out for the ingredients we spray in our gardens and on our farms.  Neonicotinoids work as an insecticide by blocking specific neural pathways in insects’ central nervous systems.  At ‘sub-lethal doses’ the chemicals impair bees’ communication, homing and foraging ability, flight activity, ability to discriminate by smell, learning, and immune systems – all of which have an impact on bees' ability to survive.  Neonicotinoid pesticides have been linked to the dramatic collapse in bee numbers over the last decade.

Domestic Sprays that contain neonicotinoids - Many domestic gardening products on sale in hardware stores and garden centers contain these chemicals.  If you're buying any kind of pest control check the ingredients – anything that contains acetamiprid, imidacloprid, thiacloprid or thiamethoxam should be avoided to maximise bee health.

While the topic of bee safe sprays is relevant topic it is also one that can also be rather confusing. There are so many different garden sprays available in the market place and so many different chemical names, brand names and generic names that making a considered choice can seem impossible. We have tried to simply the issue below by providing some brand names commonly available in the New Zealand market place.

• There is evidence overseas that the use of a group of pesticides known as neonicotinoids cause bees to become disorientated when out foraging and may be a major contributor to the phenomenon of Colony Collapse Disorder which is decimating bee populations in Europe and North America. Neonicotinoids have also been shown to cause chronic bee mortality through reduced immunity.
• Bees do not have to come in direct contact with the spray residue, they can absorb the neuro-toxins via the plants pollen and nectar.
• The common names for neonicotinoid insecticides are Acetamiprid, Clothianidin, Imidacloprid and Thiamethoxam.
• Neonicotinoids are often used for agricultural applications but can also be available to the home gardener. The two products that New Zealand gardeners are likely to come across (containing Imidacloprid) are Yates Confidor and Yates Rose Gun.
• It is not just neonicotinords that can be harmful to bees. Other common pesticides that are toxic to them include insecticides containing Acephate, Carbaryl, Spectracide, Permethrin and the rapid flying insect killer Resmethrin, to name a few. Ther is an extensive list on Wikipedia under pesticide toxicity to bees.
• Sprays that are safe to bees if sprayed at dusk when the bees won’t be foraging for a number of hours (i.e. they are safe to bees as long as they are dry and no longer wet): Spinosad (Yates Success Naturalyte Insect Control), Yates Guardall, Yates Mavrik Insect & Mite Spray, Pyrethrum (Yates Nature's Way Fruit & Vegie Gun, Yates Insect Gun Ready to Use, Yates Natures Way Pyrethrum, and Neem Oil.
• Sprays that are safe to bees (though it would still be best to spray them at dawn or dusk when bees aren’t flying): Sulfur, Serenade, Insecticidal Soap Based Sprays (Yates Nature's Way Insect & Mite Spray and Yates Mite Killer), Petroleum based oils (Yares Conqueror Spraying Oil), B.T. (bacillus thuringiensis), Herbicides (like round-up).

So if you are at all interested in the survival of honey bees, please DO NOT USE any of these toxic chemicals.

Others are bad too, although not as dire, and in the next post I'll outline how I research these things properly and how you can find out what ingredients are suspect, rather than just relying on the supplier saying it is "not toxic to bees".

How to Kill a Wasp Nest

Oh the weekend we went and dealt to a wasp nest. It was up in the roof space of a shed on one of our host's properties. The wasps had crawled in through the gap between the roofing and the wall cladding. Looked like there were a whole heap of them too, they were quite busy coming and going.




Intrepid beeman put his head right up in the flight path and gave them a few good puffs (or maybe half a bottle?) of dust2dust, which is a permethrin based powder (note: this is not a sponsored post!).

We could hear the wasps starting to hit the tin roof next door in just a couple of minutes, as they conked out, so it worked pretty quickly.

Then we went inside and had a cuppa and a yarn - my favourite part of these bee visits.

After a bit, we could see that the steady flow out of wasps from the nest had slowed to possibly nothing, the ones coming in were still a steady stream.

The plan is to go back in a week or 2 to check if they are all dead, may be give them another puff or 2 to finish them off.

Its not great killing things, but it not-greater having wasps killing your bees.

Tutin levels are high this year

This year higher levels than normal of tutin are being detected, especially on the east coast of the North Island of NZ.

Watch this video from the Bee Products Standards Council for a good description of tutu.

The short answer is, DON'T EAT COMB HONEY unless you have had your honey tested, and be really careful eating extracted honey that has been blended. If you are selling honey you are legally required to get your honey tested for tutin.

I also wrote about this in this blog post.

Varroa Free Bees to save the world

Our world's food supplies rely heavily on bees for pollination. But they are increasingly under attack from various causes, creating colony collapse disorder. But here is good news of an amazing dude who has been working hard on bees in Niue since 1999. That's 16 years, so patience is often required when working with nature, as this guy must know.

Check out the article Creating a Global Bee Sanctuary . And for more information see their fund raising page.

Control of Varroa in beehives

To have healthy strong hives, the varroa mite needs to be treated. This is usually in spring before the honey flow, and again in autumn after the honey flow. We are getting ready to put varroa strips in our hives now that the honey harvest is nearly finished.

There are different types of varroa treatments, with different chemicals, and a few non-chemical methods too. Some varroa build up resistance to some chemicals, so each hive needs to be treated in a variety of ways over the course of a year.

Toxic Honey poisoning from Tutin

From January till late May we all need to be careful of eating comb honey from hives. Toxic honey can be created from this time of year on, for the rest of the season. And it is a Big Deal - causes stupors and violent convulsions, so the websites say. Not something you want, for sure.

Toxic honey is created when there is flowering tutu around. 

Photo credits of tutu: NZ Plant Conservation Network

The passion vine hopper feeds on the tutu, then exudes a sticky honey dew substance. The bees feed on the honey dew and take it back to the hives to create honey.

Passion vine hoppers start life as fluffy little insects (which my kids called fluffy bums when they were little), then become little moth type insects that flit and bounce around.

Photo Credit of Passion vine hopper: TER:RAIN

This is a serious problem, and there is an official MPI Food Safety Standard to control it. Part of this involves testing all harvested honey for tutin, and all our honey is tested before release and sale. 

The biggest danger is eating comb honey, because the toxin is likely to be concentrated in a small part of the comb, rather than mixed with various sources as happens with extracted honey. Also, times of drought make tutin poisoning more likely, as the bees run out of other food.

For really good pictures of tutu and more detailed information see the TER:RAIN website.

And if you want to read the full standards check out the NZ Food Safety document. 

If you think you have tutu around and you have beehives, the best thing to do is chop it all down.

Breeding Varroa resistant bees

There is scientific work going on to try and overcome varroa, that destructive mite that kills bees. Currently the only way is with chemicals. But check out this short (6 min) Ted talk on this.

TedTalks 11 May

There is also a very cool 60 sec video in it, of the first 21 days of a bees life, where you can watch the baby bees hatch.

Bees and Wasps

How to tell the difference between bees and wasps? Now I am no expert at all, but the beekeepers are. And it is important to tell the difference, you don't want to squash the wrong thing, or let the wrong thing prosper either. There are a few good summaries online including the Te Ara Encyclopedia. 

This is a bee, pic from the Ministry of Health. Little furry yellow number, similar to the ones in the hive above.

This one is one type of wasp, pic from Landcare. Smooth and evil looking. Bit Darth Vader really. For more on NZ wasps, including alien pics, check out the Landcare website.

And here are our wasp traps. Recycling in action. It would be better still, instead of trapping them and poisoning the wasps, to find the nests and deal to them that way, but in the bush it can be quite a mission to locate them.