How the Varroa Mite’s True Diet Was Discovered(entomologytoday.org)
entomologytoday.org
How the Varroa Mite’s True Diet Was Discovered
https://entomologytoday.org/2019/02/21/inside-look-how-varroa-mite-diet-discovered/
42 comments
I'd love to see more science reporting like this. I think the authors did a great job of explaining the process of discovery: anomalous findings made them question what was wrong with the current theory -> initial steps to see what could possibly replace the current theory -> verification of their proposed replacement. Plus the picture are awesome.
As a beekeeper, this is my bees’ #1 enemy. Understanding Verroa mites better means better protection for our bees.
The mites are quite visible. I think a computer vision system could wipe them out.
As bees leave or enter the hive, they pass by a camera. The computer determines their fate. Infected bees get sucked up, zapped with an electric spark, or zapped with a laser. If you want to get fancy, you could aim a laser right at the mite and thus disinfect the bee.
As bees leave or enter the hive, they pass by a camera. The computer determines their fate. Infected bees get sucked up, zapped with an electric spark, or zapped with a laser. If you want to get fancy, you could aim a laser right at the mite and thus disinfect the bee.
You might already be onto it, but if not, have a look for Randy Oliver and Oxalic acid [1]. Or, more locally for me, this mega thread [2] on homemade treatment strips. They work, they are cheap and so far there is no resistance.
[1]http://scientificbeekeeping.com
[2]https://www.nzbees.net/forums/topic/10061-oxalic-and-glyceri...
[1]http://scientificbeekeeping.com
[2]https://www.nzbees.net/forums/topic/10061-oxalic-and-glyceri...
If you are an amateur beekeeper and not concerned about the amount of honey you produce there is another way to get rid of Varroa. Just let colonies swarm naturally! Because the old queen goes with the swarm and new one doesn't lay eggs for a few days Varroa mites don't have anywhere to breed. That way their population crashes to manageable levels and colonies survive the winter without dying off. And yes, I did control Varroa this way for years. Obviously this doesn't work on a commercial scale due to colonies swarming just when it's time for them to be productive ;)
Now that is an interesting story that I have not seen anywhere.
So if I'm understanding you right, this danger to bees is a sort of hack where our business-needs (namely being able to control what we pollinate and when) cause us to tend these colonies in a way that removes a security precaution (the honey bees "cleaning house" regularly) and these mites happen to be in a great position to shamelessly exploit that precaution and grow beyond bound?
So if I'm understanding you right, this danger to bees is a sort of hack where our business-needs (namely being able to control what we pollinate and when) cause us to tend these colonies in a way that removes a security precaution (the honey bees "cleaning house" regularly) and these mites happen to be in a great position to shamelessly exploit that precaution and grow beyond bound?
You are correct in that the ways we commercially keep bees (our 'business needs') override the mechanisms honeybees evolved for defense against disease.
Swarming is just one of many natural behaviors that enhances the bees' ability to survive. This paper from a prominent bee researcher highlights 20 significant differences between how honeybees evolved to live and how we keep them today, all of which reduce the 'exquisite fit' with their environment:
https://www.naturalbeekeepingtrust.org/darwinian-beekeeping
Swarming is just one of many natural behaviors that enhances the bees' ability to survive. This paper from a prominent bee researcher highlights 20 significant differences between how honeybees evolved to live and how we keep them today, all of which reduce the 'exquisite fit' with their environment:
https://www.naturalbeekeepingtrust.org/darwinian-beekeeping
Swarming cleans house, sort of. They swarm to similar spots or old empty and potentially diseased ones. If you want to find a swarm, so where you last found one. Bees love going into old comb and it’s not a good habit.
If you're an amateur beekeeper chances are high you're in a populated area, and it's irresponsible to let your hives swarm repeatedly.
I'm also not convinced this works; hives generally swarm in the spring, and most beekeepers also do a round of treatment in the fall to knock down levels for the winter. Harvesting drone brood is a common way to achieve the same thing you're trying to do, and can be done any time of year.
I'm also not convinced this works; hives generally swarm in the spring, and most beekeepers also do a round of treatment in the fall to knock down levels for the winter. Harvesting drone brood is a common way to achieve the same thing you're trying to do, and can be done any time of year.
I’m not sure why this is so down voted as it is accurate. Treatment is in spring and autumn and for some, all winter. It’s basically whenever there isn’t honey onboard and sometimes when there is.
Swarming radically reduces honey production (swarm versus non swarm honey production is about 10kgs versus 80kgs for me this year, YMMV).
Swarming is not good management, results in exterminators being called and irritates people. It’s also destructive of property depending on where they go. And what if you don’t catch them? It’s good that the new colony has less varroa, but if it’s not yours anymore it doesn’t really achieve anything.
The structured approach taken by this team to answer their research question ("what does the Varroa feed on?") is exemplary, and inspiring to read about. Thank you for sharing this article!
This sort of thing is a good reminder of just how shallow our knowledge of the world often is. There's often this perception that we know so much, but in reality our ignorance is not just vast but also readily at hand. Bees are the core of a multi-billion dollar industry in the developed world, and yet for decades we knew very little about one of the most important aspects of beekeeping (varoa mites).
Also, this is a reminder of the degree to which the modern world is utterly dependent on science and technology and yet at the same time vastly under-invests in critical research. Half a dozen people cracked this mystery. Imagine how much progress we could make if we had better funding for science and research across the board.
Also, this is a reminder of the degree to which the modern world is utterly dependent on science and technology and yet at the same time vastly under-invests in critical research. Half a dozen people cracked this mystery. Imagine how much progress we could make if we had better funding for science and research across the board.
Does anyone know how the pictures are made? Are they colorized by hand or is there some algorithm for doing it?
Probably drawing a mask boundaries first and messing with the tone balance button inside the mask until achieving the desired tone
Amazing scientific work.
Great story, amazing and gruesome pictures! Thanks.
Lovely science!
Brilliant!
the mite sticking between the bee's exoskeleton plates reminds of a dagger hit under/between the plates of an ironclad knight.
Interesting that no self-cleaning (or mate-cleaning) behavior has emerged. May be, given the bees vision, the attached mite isn't distinguishable from the rest of the bee?
Interesting that no self-cleaning (or mate-cleaning) behavior has emerged. May be, given the bees vision, the attached mite isn't distinguishable from the rest of the bee?
I'm just getting into beekeeping so take this with a pinch of salt, but I've read that in the region that Varroa are native to, native bees are able to clean themselves. The problem is that bees from other geographies which do not have this behaviour are (currently) sitting ducks to these mites.
Mite reproduction is hard to inhibit for both the bees and beekeepers. Female mites sneak into brood cells (cells used for bee reproduction) before the cells are capped and hide under the developing bee young. Once the cell is capped, the bees outside are unaware of what's happening within the cell. The mites lay their eggs within the capped cell, the eggs hatch, mate and emerge along with a diminished bee. This means Varroa treatments (such as oxalic acid vapour) only work if there are no capped brood, which only occurs at certain times during the year.
On the topic of vision it's worth pointing out that bees spend the majority of their time within the hive where it's completely dark. They only go out to forage late in their short lives. Their lifespans increase for winter, and they stay within the hive until spring. All that to say, they can't rely on vision for most of their activities. Their various dances (of which the waggle dance is probably the best known) are actually felt rather than seen. For this reason, I believe they could not rely on vision for mite hygene.
Note that Varroa is only one of the troubles that bees face! There are also hive beetles, wax moths, European foul brood, American foul brood and more, depending upon geography. Asian hornets are another serious problem in some regions.
Despite all this I would encourage anyone to look into beekeeping and see whether they find it interesting. I feel like I've discovered a fascinating and lovely niche with a great community around it, and I wish I'd gotten into it earlier.
Mite reproduction is hard to inhibit for both the bees and beekeepers. Female mites sneak into brood cells (cells used for bee reproduction) before the cells are capped and hide under the developing bee young. Once the cell is capped, the bees outside are unaware of what's happening within the cell. The mites lay their eggs within the capped cell, the eggs hatch, mate and emerge along with a diminished bee. This means Varroa treatments (such as oxalic acid vapour) only work if there are no capped brood, which only occurs at certain times during the year.
On the topic of vision it's worth pointing out that bees spend the majority of their time within the hive where it's completely dark. They only go out to forage late in their short lives. Their lifespans increase for winter, and they stay within the hive until spring. All that to say, they can't rely on vision for most of their activities. Their various dances (of which the waggle dance is probably the best known) are actually felt rather than seen. For this reason, I believe they could not rely on vision for mite hygene.
Note that Varroa is only one of the troubles that bees face! There are also hive beetles, wax moths, European foul brood, American foul brood and more, depending upon geography. Asian hornets are another serious problem in some regions.
Despite all this I would encourage anyone to look into beekeeping and see whether they find it interesting. I feel like I've discovered a fascinating and lovely niche with a great community around it, and I wish I'd gotten into it earlier.
Have a look at other OA application methods. There are safer and less labour intensive ones than vapourisation. The science behind it well covered by Randy Oliver. http://scientificbeekeeping.com
> Interesting that no self-cleaning (or mate-cleaning) behavior has emerged.
Actually, several behaviors have already emerged. Bees can groom each other to remove the mites, and they can also display hygienic behavior where they open up cells with infected larvae and removed them.
Apis mellifera has not historically lived with Varroa, but it's close relatives have and they successfully developed a stable host-parasite relationship with the mites. Wild honeybees left alone have quickly (a decade or two) adapted to the mite to develop this same stable relationship. Insect generations are short which enables more rapid evolution. In this case, the re-emergence of some now strongly adaptive alleles.
There are many beekeepers today breeding honeybees with these specific behaviors in mind, to avoid the need for chemical treatments. This is not the norm, but it's taking on more importance in the face of an escalating arms race - mites can evolve resistance to chemical treatments, too. It's also not just these behaviors that help honeybees live with mites. Many of the ways humans keep bees commercially to make things easier for us actually make things harder for the bees.
Actually, several behaviors have already emerged. Bees can groom each other to remove the mites, and they can also display hygienic behavior where they open up cells with infected larvae and removed them.
Apis mellifera has not historically lived with Varroa, but it's close relatives have and they successfully developed a stable host-parasite relationship with the mites. Wild honeybees left alone have quickly (a decade or two) adapted to the mite to develop this same stable relationship. Insect generations are short which enables more rapid evolution. In this case, the re-emergence of some now strongly adaptive alleles.
There are many beekeepers today breeding honeybees with these specific behaviors in mind, to avoid the need for chemical treatments. This is not the norm, but it's taking on more importance in the face of an escalating arms race - mites can evolve resistance to chemical treatments, too. It's also not just these behaviors that help honeybees live with mites. Many of the ways humans keep bees commercially to make things easier for us actually make things harder for the bees.
Wow, they’re like biological versions of diatomaceous earth, except they are burrowing to get at bee fat.
It has and is being bred for. It’s know as hygienic behaviour. Results vary and it’s far from perfect.
You can interrupt whatever that varroa are doing with icing sugar. You shake a cup of bees with icing sugar in there. Anything above 2-3 varroa per cup of bees is the standard treatment threshold. It’s horrifying to see 15 fall off a cup of bees from a strong, healthy looking hive. Varroa are awful.
I’ve just noticed that for first pic in that article is labeled with a scale saying ‘200mm’ presumably it’s supposed to be .2mm (I cant get Greek on my phone).
You can interrupt whatever that varroa are doing with icing sugar. You shake a cup of bees with icing sugar in there. Anything above 2-3 varroa per cup of bees is the standard treatment threshold. It’s horrifying to see 15 fall off a cup of bees from a strong, healthy looking hive. Varroa are awful.
I’ve just noticed that for first pic in that article is labeled with a scale saying ‘200mm’ presumably it’s supposed to be .2mm (I cant get Greek on my phone).
One of the main reason that the hygienic behaviour from apis melifera is far from perfect is that they didn't have the need to.
There are so many ways they are treated for varroa all year round (except high season) with "chemicals". They were simply not forced to develop a distinct hygienic behaviour. But every treatment damages the hive and puts the bees on risk.
Thats why, in the last years, the selected breeding "movement" started growing.
There are so many ways they are treated for varroa all year round (except high season) with "chemicals". They were simply not forced to develop a distinct hygienic behaviour. But every treatment damages the hive and puts the bees on risk.
Thats why, in the last years, the selected breeding "movement" started growing.
You are right. The scale of one of the pictures appear to be mis-labeled as 200mm. I believe, based on the other pictures, it should be 200um (micrometres).
The article says "200 microns" as well.
There is some "eco-friendly" spray that can incite the bees to clean themselves. It is not as effective as other methods against Varroa. You probably want the adult bees to clean the pupae as well somehow, the biggest problem is when the mites mess up the pupae - you can end up with a population of crippled bees that stands no chance of surviving.
The problem is that to fight against Varroa effectively, all the beekeepers in the area have to fight Varroa. That just doesn't happen, so I feel like natural selection will be the way out.
The problem is that to fight against Varroa effectively, all the beekeepers in the area have to fight Varroa. That just doesn't happen, so I feel like natural selection will be the way out.
> The problem is that to fight against Varroa effectively, all the beekeepers in the area have to fight Varroa.
Not to mention wild bee colonies also have to be treated or eradicated.
Not to mention wild bee colonies also have to be treated or eradicated.
They are gone where I am. Without treatment varroa gets them within a season. This helps reduce American foul brood risk but that’s a very small upside in a very grim situation.
Articles like this are one of the main reasons I regret not pursuing a profession in entomology. Excellent article, nicely detailed. I wish I had access to the equipment and facilities used to make this amazing discovery.
Oustanding work!
That was a good read, thanks.
I'm amazed by how we're constantly getting better at discovering the real cause of many things.
I’m always amazed at how little we actually know!
So, what unilaterally “bugs” the Varroa Mite?
Psuedonscorpians! http://apicultureconference2016.co.nz/wp-content/uploads/201...
Would be a cool use for a cool animal, but the effect of pseudoscorpions was not signifiant in this article. Groups Untreated and with Chelifers having almost the same Varroa counts at the end. No effect in reduction of Varroa is the first conclusion of the article.
Yes - they definitely feed on varroa but getting sufficient numbers in the hive for varroa control is the difficulty.
I’m away of a trial underway in New Zealand but that’s about the extent of my knowledge.
The imaging in this article is incredible. Worth it even just for that.
So, I am assuming that the uptick in the volume of varroa during the August-September time frame might be because of the transition of the summer worker bee to the winter worker bee. The winter bee tends to have more fat, at least that is what I have read. Therefore, there might even be a correlation between the uptick during this time due to the bees developing more fat for the over wintering of the hive and a larger increase of the mite? Could this contribute to less ‘over wintering bees’ and hence the downfall of the hive due to lack of warmth?
Where in the world are you - the uptick relates to the season but I’m unsure which season your pointing to.
I’ve inderstood it to be as follows:
Treatment comes out as honey supers go on.
Varroa numbers start to grow as brood area expands and more drones are produced (which they prefer).
At the end of the season there are a lot of varroa but the brood area starts to shrink. This is disastrous for bees as the percentage of cells with varroa in them is now very high. Deformed wing virus et al start to become very obvious. This is probably the peak in varroa numbers that you refer to.
Late autumn or winter arrive, bees are dying as the virus load is too high. Even treatment probably won’t work at this stage. The brood is now longer all covered and starts to die. Swarms happen as bees try to abscond from the dying colony.