The honey bee Apis mellifera is the most important crop pollinator worldwide, contributing an
estimated 600 billion dollars to annual global crop value.
Despite their importance as pollinators, the health of honey bees is declining, with annual
colony loss rates as high as 45% in the United States.
The primary biological threat to honey bee health is the parasitic mite a Varroa destructor,
which I have covered many times in this channel.
Varroa is both a physiological burden and a disease vector to its honey bee host.
Numerous interventions exist to control a Varroa mite, including chemical treatments
such as synthetic miticides, organic acids, and essential oils, and mechanical techniques
such as drone brood removal, brood interruption, and the use of Varroa-resistant honey bee
stocks.
The majority of beekeepers in the United States currently use synthetic miticides to control
a Varroa mites despite evidence of negative sublethal effects and honey contamination.
One promising avenue for achieving sustainable, effective Varroa control is the selective
breeding of Varroa-resistant honey bees.
Meaning that we can breed better bees to fight varroa themselves without the need for any
chemical in the hive.
However, existing selection methods tend to trade efficacy for efficiency, because the
methods that achieve the highest levels of a Varroa-specific hygienic behavior are very
time-consuming and demand greater technical skill.
It is a fact that nobody in the beekeeping industry wants to continue to use miticides
or any other heavy chemical inside the hive, and the selection of bees that can take care
of themselves is a great goal for beekeepers.
So, what if we could develop a science-based way to select varroa-sensitive hygiene without
the demand for specialized labor-intense techniques?
Dr. Kaira Wagoner, a research scientist at the University of North Carolina in Greensboro
make the discovery that later would become a very interesting tool for beekeepers to
select bees able to fight varroa mite and Deformed wing virus by themselves.
In her 2019 publication, she describes the discovery of specific molecules from varroa-sensitive
genetic stocks that serves as a bridge of communication between the infected pupae and
the nurse bees been triggered to remove the sick brood.
Now researchers know the molecules sick pupa release that triggers nurse bees to remove
them from the nest.
With this new knowledge, Dr. Wagoner and collaborators immediately jump into a new challenging project.
The development of an assay where beekeepers can screen their own bees looking for the
ones able to fight varroa and viruses by themselves.
After several years of hard work and field trials in different locations, Dr. Wagoner
and collaborators developed the first-ever varroa-specific hygienic behaviors evaluation
system.
Today to find bees with high levels of hygienic behavior we use a tedious method where we
freeze brood and wait to see how many of these frozen pupae are removed from the hive.
The freezing methods work like this: You go to the field with a tank of liquid nitrogen
which is very dangerous to handle, by the way, then you need to find the hive, open
the hive, get a frame of brood with capped brood, that we have enough space to do the
test.
Then you use a PVC tube that you fill with liquid nitrogen so you can kill a specific
area of the capped brood.
Then you put it back everything, you close the hive, and go back after a couple of days
to count how many of the dead brood was removed from that frame.
With that number in mind, you do some calculations to estimate the levels of hygienic behavior
that a specific colony has.
It is not a bad way to do it.
However, it is not specific.
The molecules activating hygienic behavior there are molecules been released by dead
brood by freezing, that is all.
It doesn't help us to understand better the biology behind it so we can improve it.
The new way Dr. Wagoner developed, we go to a hive with a simple spray bottom containing
a harmless solution and perform the same procedure as the freezing method.
You find a hive, you find capped brood then instead of using liquid nitrogen you just
spray the new coupons on the top of the capped brood and wait for 2 hours to count how many
broods were uncapped.
This is another good part of the procedure.
Because the brood is not really dead.
Hygienic bees will open the capped brood to evaluate the situation and they end up not
removing them.
Meaning that you also don't need to kill bees for this new procedure, which is always welcome
in honey bee research.
The main question now is.
Does it work?
How does it compare with the traditional method of freezing?
How does it correlate with Varroa levels?
It will be useful for beekeepers to select genetic stocks.
The data shows that the new assay that she called UBO "Unhealthy Brood Odor" was negatively
correlated with Varroa infestation levels.
Meaning, the higher bee's response to the spray compounds, the lower the Varroa mite
infestation in real-life situations in the field.
The results could be repeated in the two months tested.
(June and August).
Dr. Wagoner also tested the traditional method, FKB "Freezing Killed Brood" on the same hives
to compare.
The freezing test also negatively correlates with varroa infestation levels.
However, the correlation could not be repeated on both months tested.
Another result that got my attention when you compare the two methods was that the colonies
with a high response to the new method showed a varroa mite infestation level below the
recommended level to treat for varroa.
Meaning that if this data is correct, beekeepers will be able to select colonies that will
require non or very little varroa treatment.
Results like this are very encouraging because it not only gives us a new tool to help honey
bees to fight varroa mites but also open research opportunities for us to understand hygienic
behavior better.
The article is full of other interesting experiments and I will leave a link in the description
of this video if you want to check it out.
Or if you are a patron of this channel I published a 20 minutes presentation going over all the
results about this article.
Check it out.
I invited Dr. Kaira Wagoner to join me in a live stream to discuss her findings.
The Livestream is scheduled for Sunday, December 19 at 8 pm ET.
It is free to everyone and I will leave a link in the description of this video so you
can register to receive more information.
Is hygienic behavior good or bad for honey bees?
Please take a look at this footage:
This at the center of the screen are hygienic bees doing their job.
What you are about to see is what really happen in real time.
They are removing a sick brood and in doing so they consume part of that.
Cannibalism as I mentioned in another video in this channel.
If you follow this channel for a while you know why I am bringing this footage to you
today.
In a previous video I covered that hygienic behavior are able to spread viruses so there
is that question in the air that we might need to address.
Is hygienic behavior good or bad for honey bees?
In a previous video I show that there is a chance that hygienic behavior maybe might
be hurting the bees.
Now in this video I brought dr.
Kaira, showing that hygienic behavior might be good for honey bees against varroa mites
and virus itself.
So what it the point of me bringing this to apparently conflicting results.
It is just to illustrate how science really works.
I talk to a lot of beekeepers when I visit them.
And people sometimes are skeptical about science.
And what I realize is that people don t know what science is or how science works.
In a scientific community we are looking for new data all the time.
We are experimenting all the time.
And with time science correct itself.
We have different groups working in different approaches, different methodologies, and with
time and everybody checking each other s work, we come up with the best experiment with the
best demonstration.
And that is how things works.
Real truth come form years and years of studies and people questioning each other and doing
more experiment and repeating the experiments in different locations with different people
and that is when we establish new truth new knowledge.
Scientifically demonstrated.
So we are going to discuss this with Dr. kaira on Sunday and I want to invite everybody to
join us live on Sunday December 19h at 8PM ET.
So we are going to discuss this subject about is hygienic behavior good or bad for honey
bees.
So I hope you enjoy it.
Thanks for watching and I see you guys in the next video
InsideThehive.TV the show about bees.
See you guys next time.