Tag Archives: overwinter

Dead Colony Forensics by Dewey M. Caron

About a dozen brave individuals gathered at the Zenger apiary colonies Sunday April 15th, during a steady Oregon liquid “sunshine” rain for dead colony forensics with Dewey.  Photo right by Mandy Shaw.

Temperature was low 50’s, with only a couple foraging bees venturing forth from 4 of 8 colonies. We hefted boxes and did autopsy on two dead-outs.

Bees die overwinter for a number of reasons. By doing a dead colony autopsy we seek to determine what might have been the likely reason for non-survivorship.  Understanding the why might help us avoid a repeat this next winter.

The first dead-out we looked at (photo above) proved to be a tough diagnosis.

The colony was a mid-May nuc donation from Beetanical apiaries of Lane Co. Hive had a standard and a shallow. The shallow frames were quite full (>3/4ths of cells) with capped honey. The shallow was lifted off and placed on upside-down cover.  There were dead brood remains on three frames of the lower standard box plus a small (<2000) number of dead adult bees on the screen bottom board and outside the entrance. Two adjacent frames had widely scattered capped brood cells extending in an oval  covering over  1/3 of the middle of the frames; there was a fist-sized patch of compact capped brood but it was not contiguous with the scattered brood of the other two frames. There was no evidence of a dead cluster but a considerable number of cells of stored pollen on 5 frames. Ample mold was evident in pollen cells and as a powdery grayish mold on surface of cells. Colony was sampled for mites with a sugar roll in September and had only 2 mites (<1%).  It was NOT treated for mites as it was a non-treatment control. Colony was alive in a mid-October inspection.

Photo of the three frames with brood shows the frame with a patch of compact brood (held  in my right hand) and two frames with very scattered brood (one in my left hand and the third on top of adjacent hive; this frame is shown isolated in photo right). Full super on ground.   Photos by Deb Caron.

So what can we diagnose? Lots of honey and pollen stores so we can likely rules out starvation. Small number of dead bee bodies suggests a small colony but if we would believe death from a too-small population of adults, there should have been evidence of a cluster with bees within cells and dead bee remains on the frame(s).  There wasn’t.

Thus our best guess is a colony that had a BEE PMS condition. The scattered brood remains on both sides of the two frames suggests this –a spotty (snot) brood situation MIGHT have been diagnosed in the October examination, but this requires a close examination of the brood; we might have noticed evidence to too few adult bees to cover the brood – both are subtle clues. The fist-sized brood area,  one frame over from the other two frames with scattered brood, might have been bees trying to escape the high mite numbers and their unhealthy brood of the 2 frames with scattered cells. Adult bees were likely dying prematurely and abandoning their (unhealthy) hive, thus the reason we saw only a smallish number of adult dead bees. The colony likely failed to rear sufficient fat, fall bees. The colony probably died within a month after the last October inspection, probably from a virus epidemic related to the mite infestation. NOTE: The September mite sample is misleading/confusing (we would expect it to have been higher); if an additional sample was taken it would perhaps have been higher?

The second dead-out was a more standard necropsy. Hive was a spring split,that struggled all season. It had 2 shallows. Colony had a 19 mite count (6%+) in September and was treated with 2 formic pads between the two boxes. It was alive in March (this spring) but noted as small. It was fed dry sugar on paper (some still remaining) and provided with a frame of sugar candy.

Opening the top and removing moisture trap, (all Zenger hives had moisture quilt traps at top) showed a dead cluster of adult bees on 3 frames in top box at top of the box extending down about ½ way on the 3 frames (see photos; in photo right, hive tool is showing the remaining dry sugar on paper – quilt trap with wood shaving lower right). The adult bees were black and showed excessive moisture; there were many maggots (scavenger fly) feeding on the dead bees. There was capped brood in compact pattern within the cluster. Dead adult population was small (perhaps 8-10,000 bees). There was NO capped honey in any of the frames of either box. Lower box was empty. There were some dead bees on solid bottom board. There was little mold.

So what was diagnosis? The dead cluster is characteristic of a colony that overwintered the tough months (Dec-Feb) and moisture of adult bees, maggots and little mold suggests recent death. The compact brood shows the colony was starting to expand in the spring (flight was noted in March). Although dry sugar (as candy and crystal sugar) was given as emergency feed (hefting would have revealed lack of enough stores), it turned out to not be enough — colony likely starved. Bee cluster too small to generate enough heat to make slurry out of dry sugar or candy so bees couldn’t use it. Photo below shows one of three frames. We see “bee butts” under the dead cluster and compact capped brood.  Photo by Deb Caron.

All frames, except one with high number of drone cells, could be reused for anew colony installation (package, swarm, split). Brush off dead cluster and from bottom board. If inclined wash mold with bleach or vinegar solution.

“Russians is the way to go”

All natural top bar hive with Russians is the way to go. A thriving overwintered hive for this beginner.

RESPONSE: Glad you like them. THEY are HOWEVER NOT the best hive for everyone, nor are Russian bees the best honey bee for most beekeepers in the US

Dr. Caron’s discussion on fall feeding

Feeding Fall Colonies     by Dewey M. Caron

Feeding bees in the fall is unquestionably a way to make the fatbeedifference in whether a colony survives overwinter or not.  When colonies are light on food stores, feeding a heavy sugar syrup or not extracting stored honey can improve winter survival. It is the best management option to insure the proper fall configuration and promote raising FAT fall bees. To raise Fat bees the colonies need to be FAT with honey.

honeystoresFor improved wintering success, it is important to ensure the brood nest is situated low in the colony before fall ends. Ideally, an ample ceiling of fully-ripened honey will be stored above the brood nest enabling bees to eat their way upward through the overhead stores as winter progresses (See Diagram left). If colony brood nest is still sitting high in the colony mid-Aug/early September, I recommend beginning supplemental feeding soon.

Should honey be fed? Honey can be fed to fall colonies if you know it is from colonies free of disease, particularly American Foul Brood. The easiest way to feed honey is to redistribute honey from colonies that possess heavier stores to those light on stores. Do not rob colonies too heavily when removing honey to extract. You can remove and store honey-filled frames in the freezer and make your extracting decision later in fall or put honey supers on one colony if you wish to treat other colonies for mites.

If you have “junk” honey (honey you don’t wish to extract or honey that has crystallized in the combs), score the cappings to make a “mess” to stimulate the bees to move it into their storage pattern. You can place such frames above the inner cover, or on top of the colony. Some people advise putting such honey beneath the lowest box on the bottom board but this will require some heavy lifting. If you have liquid honey to feed, dilute it with warm water before putting into syrup feeder (honey is best fed in a closed feeder to avoid any robbing by bees from other colonies).

Does it make a difference to feed or what sugar is fed? Data collected last year at PNW Honey Bee Survey (www.pnwhoneybeesurvey.com) losssuggested there were heavier loses of individuals who did no feeding of their colonies (33% loss rate) compared to those who did feed (27%) (See graph right). There was no difference in improvement in loss percentage whether sugar syrup (sucrose as cane or beet sugar mixed with water), corn syrup, drivert, fondant or frames of honey were fed (see graph below).  For latest fall and earliest spring  feedings, generally a clean, non-contaminated sugar is recommended.  Some individuals do not care to feed corn syrup (high fructose syrup) nor beet sugar (it comes from a GMO crop). During the active season, sugars with contaminants, (darker sugars, syrups with corn syrup, candy liquefied into syrup, etc) seem to be OK.carbs There is no indication that feeding converted sugars (sucrose already reduced to mixture of the simpler sugars glucose and fructose) offers any digestive advantage to honey bees.

Fall feeding of protein does not make for a larger colony nor improve survival. Bees apparently do not store the artificial diet material but if there is a lack of pollen stores (i.e. bee bread) in a colony, fall protein feeding can help insure FAT bees. Feeding pollen patties or dry protein material in an outside feeder does help boost growing colonies and extend the pollen availability. Pollen is not always reachable in early spring with rain and/or cooler temperatures inhibiting flight.

What is best way to feed liquid syrups? Different individuals have different ways to feed and offer different sugar sources. Basically the BEST way to feed is the one you find useful and fits within your budget. You can buy expensive feeders or be inventive and recycle materials to use as feeders. Many simply put the syrup into a recycled jar or can that has a removable lid with tiny holes punched in the lid. One or more feeders can be placed above the inner cover hole, with or without a piece of screen material, or directly onto the top bars of the top box. Three tin cans with removable lids are shown in diagram below to right directly on top of frames. An empty shell should be placed around the feeder and the lid properly weighted to avoid the empty box becoming displaced. It is easy to check and refill/replace such containers when the bees have taken down the contents.

Some feed bees in a common feeder in the apiary (feed lot feeding). I don’t like this method and it isn’t a good method for urban beekeepers since it can lead to a cloud of bees at the feeding site. It seems the strongest colonies are the ones that collect most of the syrup, not necessarily those that need it the most.

feed1I like to drill a hole the size of a plastic jar and put the feeder jar outside the lid (as shown to left).  feed2I can remove an empty jar and replace it with a filled jar before the bees have a chance to occupy the space of the hole. External feeders (shown right) are black to cause less heating of the syrup. Such feeders are available from bee supply companies.

A popular way larger-scale beekeepers use to feed colonies (rather than feed-lot feeders) is with an internal feeder. feed3They purchase or make their own Division Board feeders and place them at the edge of the box, replacing one or two regular frames (Figure to the left shows a homemade feeder at left of brood box). Most of the larger-scale beekeepers have a tank on their vehicle and a hose delivery system to refill the feeders by simply moving aside the cover and/or boxes on top of the internal feeders and then quickly refilling the feeder. This is less useful for smaller-scale beekeepers because it necessitates opening the colony and without a convenient liquid delivery system refilling can be tedious.  It is advantageous as bees will readily utilize the syrup in such feeders. They should be equipped with a ladder so bees can easily enter and exit and avoid accumulating dead bodies at the bottom.

Feed heavy syrups in the fall. We do recommend that the syrup be mixed heavy in fall feedings. This is to stimulate storage of the material vs. stimulating brood rearing. If you have liquid honey to feed, dilute it and feed in a container feeder within the hive.  Be careful when feeding in fall or during a drought so that you do not promote robbing behavior. Reduce entrances and avoid spilling honey/syrup outside of colonies.

feed4In Oregon you should seek to feed colonies the heavy syrup before the fall rainy season appears. After rains become common, we recommend switching to a dry sugar so as not to add to moisture stress to the colonies. Granulated sugar can be fed in a top rim such as a Vivaldi board or simply poured on the inner cover as shown in left photo. feed5An alternative is to make a sugar candy and place it above the inner cover hole. Alternately you can harden the candy into a rim and then position the candy above the top bars as shown in right photo. Warm moist air from the cluster below will make a slurry of the candy above the bees (or at the oval opening if inner cover is used) allowing the bees to access the candy as they need it. A good alternative is to feed more expensive fondant sugar – it absorbs moisture and will not become as hard enabling the bees to take it as they need it. These forms of feeding don’t add additional moisture stress to the winter colony. Our BeeInformed survey has shown that feeding dry sugar or candy improved overwintering success.

Should food stimulants (such as Honey-Bee-Healthy, Amino Acid boosters, probiotics, etc) be added to sugar syrups when feeding in the fall?  Although they can be good additions to entice the bees into quickly emptying feeders and stimulate healthy colonies, some advocate avoiding adding a food stimulant in the fall. If you are debating the value of such additives I suggest you try splitting your colonies into two lots, feeding one and not the other and see if you see a difference. New additives seem to frequently come on the market, but most, adapted from feeding other livestock, have not been extensively or independently tested for effectiveness or potential harmful effects.

Should you add vinegar or an acid to syrup to bring the pH down to around 4.7?  At one time, using additives to avoid sugar spoilage and mold growth in feeders was the standard recommendation. Those who feel it important to create a more acidic syrup, thought to better duplicate flower nectars (which have a wide pH range depending upon the flower and plant growing conditions) may help the bees intestinal function. Avoid toxic sugars (such as milk sugars lactose and galactose) and avoid salt as a higher salt content quickly turns bees off.

Will feeding sugar in the fall make a difference? Results from the PNW honeybee survey suggested those who didn’t feed lost more colonies than those who did feed. The best advice, try it, you might like the improvement in overwintering in your colonies.

Dewey Caron August 2015

Download PDF of this article here Feeding Fall Colonies

2015 Survey Q & A – Not for the Commercial or Semi-Commercial Beekeepers

Q-Tried to do this survey online and failed. Section4: the format did not allow to enter the necessary information and, short of making numbers up, the survey doesn’t let you continue to the next page. Very frustrating.
Section 3b: These numbers are a guess and can be misleading. All we know is that after combining, requeening with nucs, and equalizing colonies in Jan 2015 from what had been 64 overwintered “units”, we ended up with 55 queenright colonies (pollinating units for CA almonds).
Section 4 Origination: Because we sold the majority of our 2013 overwintered and 2014 split hives, these numbers are a guess (the rations not the total). It’s too time intensive to figure out form the records which of the surviving colonies originated in 2013 or as in 2014 as a split.
Section 7.1 Sorry but for me this survey looses in credibility when it uses “minimal hive inspection”, “Apiary colony configuration” and “Apiary site selection” are listed as options for mite control practices. If some people feel that way, why not let them write it in under “other”?

A-Response to Semi-Commercial Beekeeper
I appreciate your attempting to do an electronic survey on 2014-2015 bee losses. I am sorry you had such difficulties with the electronic site and had to send a paper copy. Your effort was commendable.
The survey is meant for backyarders – those with one to a couple of apiary sites – so it is not easy for operations such as —— to fit answers into the offerings (either of the electronic or paper versions).
You indicted on Section 2 – the section used to compute losses – that this was a difficult question to answer – but what you sent is exactly what we were looking for. You indicated of 64 fall colonies 55 were counted in the spring after all the management. Those with 1000’s of colonies have the same issue and round numbers to send back a survey – I realize they are only “estimating” overwintering losses – and likewise their numbers of summer losses. Our national BIP survey and this one Ramesh and I are doing for PNW is, in reality, a “snapshot” – we recognize and understand that it is not always possible to provide “real” numbers. This data is still very useful…..right now it is the “best” we can hope for with a survey instrument – we are also doing counting and surveying with “real” numbers – for example what Dan & Ellen are doing with the Tech Transfer sampling + our Tier 4 numbers (People need to pay for this survey assistance). Ramesh and students have other studies, some in conjunction with cooperators and others using OSU colonies, that are “real” numbers.
Under comment section you said the questions should be rephrased so it might be” easier/possible” to respond. In particular, you commented that survey “loses credibility when items like minimal hive inspections, apiary colony configuration and apiary site selection are listed as options for mite control practices“and you suggested that persons who feel that way should write have to include them under “other” In fact, that is the option for the paper survey sent to commercial and semi-commercial (your colony numbers would have us classify you as semi-commercial). As indicated, the electronic survey (and the paper copy you submitted) was never intended for commercial or semi-commercial beekeepers.
As for our checklist of items under sanitation – it makes sense to collect data to show what Oregon/Washington backyarders are NOT doing for proper sanitation or what COULD be done and then we see if it will make a difference – they do apparently make a difference for smaller colony numbers and may especially be effective under light mite population pressure (depending upon what we term “effective” or “success”. If basic sanitation means 10% fewer losses (about the same as some studies have shown for use of a screen bottom board for example) that could Be EFFECTVE or SUCCESSFUL by someone’s standards. Science does show that colonies in the sun (apiary site selection) have “reduced mite populations” and there is some evidence that if efforts are made to reduce drifting from one colony to the next, the mite populations of some colonies are within limits that suggest the colonies are holding their own when mite population pressures are lower – so is that “effective” or Success”?
The “kicker” is that viruses change the whole situation since it is mites + viruses that kill colonies so quickly. Also one colony generating mites in an apiary (I label them “mite bombs” in my talks) do share their mites with others in same apiary as they get weaker and under more stress. So does good sanitation make any sense? Well I don’t know – but I thought the survey could help provide some real answers – sorry you feel that by including such survey questions that the entire survey losses credibility.
Our survey – is designed to get some basic information. I am able (with 250 backyard respondents this spring) to run correlations between loss and these various options. If apiary site selection is ineffective the data should help to define this (correlation is not causation). I do appreciate your effort to be included.

2015 Survey Q & A – CCD & Beekeeping costs

Q-CCD is a serious problem!!!!!! Besides bee loss, the cost of beekeeping continues to rise which makes it difficult for most to continue or start.

A – You commented on CCD and the seriousness with rising costs of beekeeping. Beekeeping has never been ‘cheap’ and you are correct in that losing nearly 1/2 of the bee colonies each year due to CCD and other factors only adds to the cost by our need for replacement bees. As we started our work on CCD back in 2007 (when we defined the term) – and began to realize the extent and seriousness of overwintering (and active seasonal) losses, we thought there might be a single cause – that has proven to not be the case. Syndromes of losses like CCD and Bee PMS have been especially troublesome in our search for what might be the underlying factor(s) in the symptoms we see in the dead colonies.
With the heavier losses supply and demand factors of the marketplace have kicked in and people selling bees have realized with the demand that they can (and should) raise prices. I have been doing this for over 50 years – the pendulum has swung in one direction — it will swing back – if we live long enough to see it repeat past history. Bees and hive equipment will never be inexpensive but maybe more reasonable in the future.