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.
