Ask a Master Beekeeper

Most of the questions this month were about the same thing: can equipment and frames from deadouts be used to hive new packages or nucs? How can the resources be stored until the bees come? And how to arrange the box with frames of honey or pollen when installing new bees.

The short answer is yes, you can reuse the hives. You’ve spent good money on the equipment and your bees spent countless hours drawing the comb and filling it with honey and pollen. Neither of these investments should be carelessly wasted. But there is one caveat: you must be certain that no communicable bee disease remains in the hive.

Hives that perished from mites and the viral diseases they bring (by far the most common cause of hive loss, even in hives that were treated) are generally safe to use immediately. Colonies lost to starvation have no carried-over disease risk. Small hive beetles and wax moths perish in the winter wherever there are freezing temperatures. (Although both these pests may have rendered the combs unusable and in need of refurbishment. See the March 2020 Newsletter article on rehabbing frames.) Even the catch-all cause of death, “poor ventilation” will have, at most, left the hive in a soggy, moldy condition, but still usable after drying out.

What beekeepers are worried about (or they ought to be) are the brood diseases: American foulbrood and European foulbrood. Both diseases remain on the combs and interior surfaces of the boxes even after the colony has died. American foulbrood will remain viably infectious for many decades (at least 75 years.) Which is why equipment that’s been exposed to AFB needs to be burned or irradiated. By contrast, EFB contamination lasts for 18-36 months, depending on which authority you want to rely on.

How can a beekeeper tell if their equipment has had either of the foulbrood diseases on it?

With your own equipment, the most important clues are your notes or recollection of what the brood patterns looked like at the end of the season. If you were seeing clean swathes of normal-appearing capped brood right up until closeout, then the chance that the hive later died during the late fall or winter from a brood disease is low. But if your late-season brood areas were spotty and unhealthy-looking then more vigilance is called for.

The appearance of AFB and parasitic mite syndrome (consequences of unchecked varroa mite infestation) can look somewhat similar: irregularly-spaced capped cells, with sunken tops and holes in the cappings. The colony’s treatment history and your data from late summer and fall mite counts may help you sort this out. If you haven’t got that, then hold the frames upside down and look for the tell-tale evidence of guanine (mite poop). These are small white flecks in the ceilings of the cells. These clues will help you decide if mites (and viral diseases which they spread) were the likely cause of death.

Guanine deposits (white specks) on top of cell

AFB has some tell-tale signs, too. Besides the remains of a very unhealthy-looking brood pattern, look in the bottom of the cells for evidence of scale. Scale is what we call the dried-out remains of a pupa that died and decomposed in the cell. Sometimes you can see the upward facing tongue of the dead pupa in the scale. In American foulbrood the scale is tightly attached to the cell floor – you usually can’t scrape it out without damaging the comb. These scales remain visible for a long time. If there are still-gooey remnants of dead pupae in the cells, you can test them with a field test. The liquified remains may also rope-out more than an inch when stretched using a toothpick or twig.

European foulbrood, despite the similar sounding name, is a completely different disease, caused by different bacteria. Because it primarily kills larvae before they are capped, there may be less physical evidence left behind after a colony has died. And like AFB, many of the signs of EFB can look very similar to parasitic mite syndrome. The scale, if there is one, may appear to be twisted or curled along the sides of the cell. Unlike AFB, European foulbrood scales are easy to scrape out of the cell.

(A mnemonic to remember the differences about the scale: American foulbrood scales are Awfully hard to pull out; European foulbrood scales are Easy to pull out.)

Some larvae that are infected with EFB late in the larval stage may wind up being capped, resulting in death under the capping. If there are any decomposed remains, however, they will not rope out. In EFB, field notes of inspections noting good patterns late last year are important clues to rule the possibility of a brood disease in, or out. There is also a disease specific field test for EFB, but in the case of a winter deadout there is less likelihood of there still being liquid remains to test.

In both cases, you could also send a questionable frame to the USDA Bee Research Lab in Beltsville, MD for a diagnostic exam. (You won’t get it back.) See here for instructions on how to prepare a sample. NOTE: Due the present coronavirus crisis, the Lab is temporarily not processing samples for testing.

If you see any signs of the foulbrood diseases, it would be a good idea to call your state bee inspector, for an expert’s on-site opinion.

When overhauling a winter deadout, because there may have been little brood just before death, you need to look hard at the frames, to see the remaining signs. Put your time and effort into studying the frames in the brood nest area. The frames in supers, or even capped frames of honey in the brood nest have little to tell you.

And don’t let confirmation bias creep into your thinking in the case of so-called “black swan” events. Black swans are big, unexpected catastrophes that may have occurred around the time of the hive loss. Typical things of this sort could be storms that blew over hives, bear attacks, vandalism, or wildfires. In these cases, you “know” what event was associated with the hive loss. But you don’t know if that was the only thing going on at the time.

Want to see some more pictures?

An excellent, and modestly-priced, resource with good pictures of bee diseases is the Field Guide to Honey Bees and Their Maladies by Penn State. It’s easy to use and small enough to fit in your tool bucket. That way you’ll have it at hand when something catches your eye during an inspection.

How to use the brood and honey frames from a deadout

If the frames have no signs of foulbrood diseases, you can plan on reusing all the resources in the hive: drawn empty combs, any frames of pollen and honey.

If the boxes have been outside all winter in cold areas, they need not be rotated through your freezer to kill insect eggs (of small hive beetles and wax moths). Scrape out any accumulation of dead bees on the floor of the hive. Bang the individual frames to dislodge bees that are stuck on the comb, but don’t bother trying to pluck out dead bees that are head-down in the cells. Temporarily store the frames in the hive with both the lower entrance and the openings in the inner cover screened off with metal screening. This will allow air circulation to keep the frames in good condition for the next few weeks. This will keep out mice and keep robbing bees from making away with the honey.

And speaking of honey frames: some readers wanted to know if you could extract the left-over honey. Perhaps, though late season honey is often prone to granulation, sometimes making extraction impossible. But the bees can easily use granulated honey. And you may have treated the hives in the late fall and winter with chemicals which can’t be used with honey for human consumption. The very best uses of the frames are as feed for surviving bees, or as a housewarming present for new bees.

If you have a lot of frames, plunk a whole box of them on top of any hive that may need supplemental feeding in late winter. At your first inspection, you can also slot in an individual frame, or two, of honey and pollen to boost a surviving colony

If you have a more modest number, save them all for your new bees. Equip a box with some frames of honey on each side, a frame or two of pollen, and fill the rest of the box with already-drawn comb. Start your bees in a single box, but be prepared to add a second one quickly, because the bees won’t have to devote any of the incoming nectar to making wax for combs. With the extra resources already in the hive, they should take off like rockets and you should stay on top of them to avoid prompting a swarm due to crowding in the brood area. Keep your salvaged equipment (both brood boxes and supers) ready to deploy.

Dealing with deadouts is a depressing project. It can be hard to face up to your own shortcomings as beekeeper which may have contributed to the hive loss. But the bees have left you a clearly described pathway toward a different outcome this year And they have left a treasure trove of resources for you, and your new bees.