Re: [SB-beekeepers] Digest for santa-barbara-beekeepers@googlegroups.com - 4 updates in 2 topics
11 views
Skip to first unread message
Dan Smith
Jan 6, 2022, 9:07:35 AM1/6/22
to santa-barbar...@googlegroups.com
Terrific article!! It makes total sense, thanks for sharing!! My personal take away, probably like most of us here in SB, is to continue sourcing bees caught locally (not purchased) and to plant as many native plants as possible… Dan
On Thu, Jan 6, 2022 at 12:08 AM <santa-barbar...@googlegroups.com> wrote:
Pamela Wilkinson <ppwil...@hotmail.com>: Jan 03 11:29AM -0800
Free used hive parts:
1 deep with frames (in re-usable but not very good condition - frames would
need old wax removed)
3 honey supers in good condition, 2 with frames that would need old wax
removed if you want to re-use them
2 metal queen excluders
There are no bottom boards or lids.
If anyone is interested, tell me when you could come by and I'll provide my
address.
Dave Sample <dave...@gmail.com>: Jan 05 11:16AM -0800
I'm interested but I only want it if no one else responds.
Thanks,
Dave Sample
719-651-7088
On Wed, Jan 5, 2022, 10:04 AM Pamela Wilkinson <ppwil...@hotmail.com>
wrote:
Pamela Wilkinson <ppwil...@gmail.com>: Jan 05 04:42PM -0800
Hi Dave, someone took them, and when I tried to remove this post, I
couldn't find it.
Pam
Pamela Wilkinson <ppwil...@hotmail.com>: Jan 03 11:44AM -0800
This article is copied from the recent Economist Magazine and is very
interesting.
*Honey bees, Varroa mites and unintended consequences*
*Beekeepers may have accidentally helped a plague of their charges*
Dec 15th 2021
FEW PESTS are more feared by apiarists than the aptly named *Varroa
destructor*. This mite, originally a parasite of *Apis cerana*, the Asian
honey bee, has plagued *Apis mellifera*, *cerana*’s western cousin, for
only 50 years or so—having arrived in Europe via what was then the Soviet
Union and subsequently spread to both North and South America. But a plague
it is. *Varroa* is now so common that the mites are found in nearly every
hive in the United States.
Why *Apis mellifera* has proved so vulnerable is debated. It might be the
case that, being naive to the new parasite, *mellifera* had evolved no
defences against it. Individuals of *Apis cerana*, by contrast, constantly
groom each other to remove such ectoparasites. But work by Alberto Satta
and Francesco Nazzi of Sassari and Udine Universities, both in Italy,
suggests an additional possibility. This is that beekeepers themselves have
also, albeit unwittingly, helped the mites to multiply.
A *Varroa* infestation often starts when bees from a neighbouring colony
raid for its honey an infested hive that can no longer defend itself.
Pregnant female mites hop on the raiders and are carried back home by them.
Bees use the hexagonal cells of their waxy combs for two jobs: storing
honey and raising youngsters. The invaders hop off the bees that have given
them a lift, head for an area of cells prepared by the queen for
youngster-raising, and lay their own eggs on bee larvae there.
Both the mother mites and, when they have hatched, their offspring, feed by
biting through their hosts’ cuticles and sucking out bodily fluids. Some
larvae are thus killed outright. Survivors are weakened, making them
vulnerable to infections. And that vulnerability is enhanced by open wounds
left by the parasites’ feeding, which are exploited by pathogens carried by
the mites. These are known to include deformed-wing virus and
acute-bee-paralysis virus. Some researchers think that *Varroa* is also
implicated in colony-collapse disorder, in which the bulk of worker bees
desert a hive for no apparent reason.
Though honey bees are not, contrary to popular mythology, declining in
numbers around the world, *Varroa* mites do thus cause serious trouble for
apiarists, particularly in the West. Better understanding of how to keep
the critters under control would therefore be welcome. And Dr Satta and Dr
Nazzi, writing in the *Proceedings of the Royal Society*, think they have
found a possible new approach.
*A sticky question*
A crucial factor in the *Varroa* plague is, in the two researchers’
opinions, a substance called propolis—or, rather, a lack of it. Propolis is
a sticky material that bees make from a mixture of wax and resins gathered
from a wide variety of plants. They use it to coat the inner walls of their
hives, to plug holes in the hive wall that might otherwise admit predators,
and to encase the bodies of those intruders which do manage to breach that
wall and have subsequently been stung to death. Evidence is mounting,
however, that propolis serves as more than just a building and embalming
material. This evidence indicates that it also has antimicrobial properties
which help bees fend off a range of dangerous diseases, including American
foulbrood, a bacterial infection, and chalkbrood and nosemosis, which are
caused by fungi.
But microbicides are not necessarily arachnicides. So there was no obvious
reason to suspect propolis would be effective against mites as well, until,
in 2017, a team led by Dr Satta made the curious finding that hives invaded
by *Varroa* respond by sending out more foragers than usual to collect
plant resins. Since the only known use bees have for these resins is making
propolis, this suggested to Dr Satta and Dr Nazzi that the hives in
question were employing the stuff to fight their infestations. They
therefore rounded up a group of colleagues and got to work on the details.
They began by analysing honeycombs that had been prepared by queens as
nurseries. They confirmed that propolis had indeed been applied to brood
cells in these. In particular, they showed that the applied material was
rich in compounds called phenols. These are pretty toxic (phenol itself,
the group’s eponym, was the first widely used antiseptic) and would almost
certainly be bad news for mites.
To make sure, the team reared honeybee larvae in artificial cells in a
laboratory. They treated some cells with chemicals found in propolis.
Others, not so treated, acted as controls. In both of these sorts of cells,
a single pregnant mite was also introduced. A third group of cells were
treated with chemicals but kept mite-free, to determine whether the
chemicals harmed larval development in any way.
The upshot was that in the treated cells, 19% of newly hatched mites died,
whereas in the untreated cells only 6% did. And the effect was yet more
pronounced when Dr Satta and Dr Nazzi went on to monitor the subsequent
fertility of the survivors. Of those mites which outlived their initial
exposure to chemicals found in propolis, only 26% went on to reproduce. In
contrast, 46% of surviving mites in the chemical-free cells reproduced
successfully. The chemicals appeared to have no effect on the development
of the bee larvae.
It seems pretty clear, then, that propolis helps protect against *Varroa*
infestations. But this raises the question of why bees do not make more use
of it in their brood cells. A plausible answer is that the ability to do so
has been bred out of them.
Until the revelation of its antimicrobial properties, beekeepers saw
propolis as nothing but a nuisance. In particular, when hives with
removable frames, for the easier collection of honey, were introduced in
the mid-19th century, bees retaliated to this enhanced pillaging by pasting
propolis over those frames, making them hard to extract. To counter this
behaviour, generations of beekeepers have favoured colonies that produced
less of the stuff. As a result, modern bees are fairly economical with its
manufacture and deployment.
Reversing the consequences of such selective breeding will not be easy. It
might possibly be done by hybridising domesticated *mellifera* with wild
strains of the species, or with other species of *Apis* that have not lost
the knack of making propolis. For that to work, though, would require a
concerted effort spread over many places.
A more immediate response might be to make it easier for bees to gather the
phenol-rich resins which do the mite-killing—perhaps by growing relevant
plants near hives. Alternatively, a synthetic version of propolis,
introduced into hives by human hand, might then be deployed by the workers
in mite-unfriendly ways. Regardless of the exact path out of the mess,
though, the sad tale of the honey bee, the propolis and the *Varroa* mite
looks like an object lesson in the law of unintended consequences. ■
You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page.
To unsubscribe from this group and stop receiving emails from it send an email to santa-barbara-beek...@googlegroups.com.
Dan Smith
Jan 11, 2022, 9:51:04 AM1/11/22
to santa-barbar...@googlegroups.com
Great info!! I’d love to see a foto of propolis in a foundation cell, if you’re able to locate one, Amy. I’d love to know more about “reading” foundations and learning about overall hive health from them. In a similar vein, “reading” debris on the bottom board and identifying particulate matter there seems especially valuable (I use screened bottom boards with removable bottom trays).
I wonder, Jennifer, if you or anyone may know how to roughen up interior walls of deeps if one doesn’t have access to a saws all ?
Last year I had a hive abscond which left bunches of propolis, globs everywhere, it makes more sense now. I guess the hive was fighting off something, possibly varroa and associated viruses (they lost). Dan
On Fri, Jan 7, 2022 at 12:08 AM <santa-barbar...@googlegroups.com> wrote:
Kate Eden <kede...@gmail.com>: Jan 06 10:36AM -0800
Great Article Pam. Thanks for uploading it. I am currently using frames
without any plastic or wax foundation, just a guide at the top of the
frame; the bees have to draw their own wax. Perhaps this will encourage
the bees to use propolis if and when they need to. I have one hive that
took a deep with 100% foundationless frames. I haven't bothered them, and
it will be interesting to open the hive in early spring and see what they
have done.
Thanks again.
Kate Eden
On Wednesday, January 5, 2022 at 10:04:32 AM UTC-8 Pamela Wilkinson wrote:
Amy Beekeeper <amybee...@gmail.com>: Jan 06 03:10PM -0500
Awesome Pam! Thanks for posting! I have anecdotally made note of colonies coating the inside of cells with propolis possibly during high mite infestations! I have one such frame somewhere that never had young or honey put into it and so the propolis is incredibly apparent! I will have to go see if I can dig through my frames to find it and post a picture. I should add it to my teaching frame collections! I have long wondered about what I described as a “chicken vs the egg” problem with regards to propolis! What I mean is that I have wondered if hives apply lots of propolis because of disease or if the disease stimulates application of propolis. My data records suggest that it is the latter… but it would make sense that the ability to do so would be genetic. All of my bee genetics originate from feral populations so perhaps the selective pressure against propolis has been released. That suggests to me that perhaps the trait has just been suppressed or has an epigenetic basis rather than being genetically lost!
When I lived in Santa Barbara my bees were also a feral origin… and so had a high introgression of Africanized genetics and thus a higher propensity to use propolis. I have since moved to New England and that is no longer the case and so I believe i have been able to make useful observations. I really appreciate you posting this article because this topic is especially interesting to me!
Thanks,
Amy Musante, Beekeeper & Organic Farmer
Check out our Facebook Farm page for videos of our hives and chickens:
http://www.facebook.com/musantefarm
Organic Eggs, Raw Honey, and Locally-adapted Honey Bee Colonies For Sale!
At Musante’s Farm, we raise our Heritage Chickens on pasture and organic feed... and our honeybees on wildflowers!
http://musantefarm.com
Jennifer Rabe-Morin <jrabe...@gmail.com>: Jan 06 05:54PM -0800
I have deliberately roughed up the walls of my beehives to about a 1mm
depth with an electric SAWZAL. I am following Seeley's lead here who
recommends bought screens that have about .5mm deep grooves punched into
them and are nailed to the beehive walls to encourage propolis laying. My
roughened walls did have more propolis scattered over them than my
original smoother ones.
Exciting data about how propolis "sterilizes" and kills mites!
Thank you Pam!!!
Jennifer
On Wed, Jan 5, 2022 at 10:04 AM Pamela Wilkinson <ppwil...@hotmail.com>
wrote:
Dan Smith <dansmi...@gmail.com>: Jan 06 06:07AM -0800
Reply all
Reply to author
Forward
0 new messages