The Classroom – November 2018
I have been enjoying your column for decades. Keep up the good work! :)
I’ve been reading about B401 “Certan” that other countries use to kill waxmoth caterpillars in stored frames. How does it work? Is it toxic to the bees? Do we have to air it out before we put frames back in the hive? Can we use it once the caterpillars start to damage the wax?
Why isn’t it sold in the USA?
Waxmoths are a pain on stored comb for sure. Can’t really blame them, as it is food for them. It allows them to reproduce and feed their larvae, preserve their genetics and grow the population. Welcome to competitive biological life. It’s competitive, because we beekeepers don’t want them to do this, as it destroys comb.
Honey bees have enough chemical residue load issues in the beeswax comb from varroa control products, plus everything they are exposed to as they forage in the environment. When possible, when available, we as beekeeper managers need to use natural biological products. Years ago, in the US, there was a product named B401 which was a biological that killed waxmoth larvae and was harmless to me and you and honey bees. It just attacked waxmoths.
Registration fees went up and it became too expensive to re-register. The company that made it, Vita-Europe, sells lots all over the world to beekeepers, just not the US. They are thinking about reintroducing it here in the US. It doesn’t need any additional data or field trials because they all are on record and valid for this natural biological product.
I went to the Vita website, vita-europe.com, and copied the information below.
- B401 is a concentrated solution of Bacillus thuringiensis subspecies aizawai, a micro-organism, harmless to man & honey bee alike.
- 100 % efficacy against the larvae of the wax moth (Galleria mellonella).
- A 100% biological product that leaves no residue in wax or honey, does not alter the taste of honey and is environmentally friendly.
- Is suitable for organic farming in accordance with Council Regulation EEC No 2092/91 modified on 24th June 1991.
- Comes in 120ml or 1 litre containers
Q Varroa/Virus Legacy
Hope all is well within the realm of beekeeping. A quick question about one of the viruses we see affecting the hives this time of year and depleting the numbers that would be the winter bees. (I’m in the south-central Kentucky area.) It is the one you see the pupa has developed but not turned brown yet and the bees are uncapping the cell. Tilt the frame forward and the pupa will not quite fall out of the cell because of the edge of the opening holding it and tilt the frame back and the pupa will fall back into the cell.
I don’t worry about a couple of cells but when the level gets into the dozens, the numbers are affecting the winter bees. The queen always seems to fill the cells with eggs, but loses out before complete development of the bee.
What is the opinion for any course of action at this time of the year to assist in strengthening the hives affected? Mite counts are low, and I don’t practice a lot of chemical applications for control of mites and the survival rate for my operation was average when I was tested with the Honey Bee Health survey last year. The study didn’t relate who treated and who did not, but I was right in the middle.
Thank you for any reply,
H D Overholt
There are approx. 20+ viruses that have been ID’d in honey bees and several of them are now more active because of Varroa destructor mites. When varroa can act as a horizontal vector, transferring viruses between bees, it allows for the introduction of new viruses and often causes formerly benign or latent viruses that were already inside the bee to be activated and escalate out of control.
Any time an organism is exposed to a ‘new’ virus often that organism gets sick and even dies. For us humans, think of the last few years and the many new viruses: HIV, Ebola, Zika, Lassa fever, Sars. In livestock we’ve seen Newcastle disease, bluetongue, avian virus, equine anemia. The list goes on and on. Viruses are adapting and learning how to survive and thrive in this world of global trade. They’re moved around freely, allowing viruses to test their genetics out on us and livestock and pets.
Viruses like the human cold virus depend on humans being in close contact with each other, which enables the virus to pass from one to another, allowing it to spread and reproduce. Viruses in a beehive need the same condition. Yes, varroa starts the ball rolling, but the virus does not depend on varroa specifically. Honey bees touch each other, they clean up after each other, they share food with each other and all these conditions allow viruses to be shared around. Once the viruses get started, you could have varroa controlled perfectly down to 0 mites in a colony and it would still take months and months to clear viral loads out of the communal colony population.
My free advice is to control varroa using a less stress producing product like ApiGuard (thymol gel) and keep checking to see if it is working to get varroa below 3 mites per 100 bees sampled. If not move on to something more aggressive.
Reducing other stressors, specifically nutritional stress by feeding 1 to 1 sucrose (sugar) syrup, is a good idea. You can use a supplemental protein patty as well to fill in gaps in pollen collection. Sometimes replacing the queen can break a disease cycle, especially if she is spreading a virus that is chronically in her and associated with eggs or semen.
Then, like everything else in beekeeping cross your fingers. If it were easy, everybody would be doing it.
Hang in there.
Q Poof, Nothing
A bee question… My last round of new queens all started with drone brood first. Have I just never noticed, and is this normal? Are they poorly mated? Once they get going, they lay a nice, compact brood pattern, with more drone brood than one might expect around the edges.
Most of the time a new queen has trouble with regulating the amount of semen that she releases as an egg slides by the spermatheca. More sperm being the challenge rather than less. But, you said it was ‘queens’ plural which is peculiar.
I would say poorly mated, but not that she/they didn’t mate, but rather it’s more likely that some of the drones she mated with may have sperm with motility issues. Remember that a virgin queen will typically mate with 15 to 20 drones, sometimes more in a DCA (Drone Congregation Area).
The possibility of not having any reproductive ability, because of 1 drone being a dud is reduced with multiple matings. You can still have a drone ‘shooting blanks’ so to speak, but the probability of them all shooting blanks is small, and so survival of the colony is increased by mating with lots of potential dads.
Where the drones came from in the DCA that your virgins used to mate is unknown, but it is not unrealistic to think that there could be a drone producing colony in the area where the drone’s sperm was dead. So if his sperm was the first expressed, the result is unfertilized eggs and thus more drones.
Q Maybe New Product
Good morning. My name is Doug Bhatt and I live in east Texas. I am a new beekeeper with two hives. I have been reading about a product called the Bayer ‘Varroa Gate,’ which is placed at the hive entrance and the bees pass through it. As they do, it deposits a small amount of miticide to control the mite population in a hive. I cannot ….