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Hive Forensics


Or maybe better titled - "What in the world happened to my hive?"

I first wrote a version of this article last year about this time and received very good feedback from a lot of beekeepers! Turns out, we all need a “go to guide” for determining “What happened!’ With a few alterations here and there, I hope this article helps when faced with a dead out.

What is a Dead Out?

 A dead out is the name given a colony that’s dead! Well, that seems a little too simplistic right? Not really. It more implies a question than a definitive name to a result. If I say I had 3 dead outs in my bee yard, don’t I want to know why? Of course I do. If I say I had a colony die from _____, you would say OK, that’s easy, just don’t do ____ again or do ____ and that won’t happen again! If only it were that easy! The following is a broad overview of conditions and causes most commonly found in backyard beekeeper “dead outs.” Some of these conditions are “seasonal” but so many of them could be in any season throughout the year.

Hive Condition: Dead bees head down in cells and/or a group of dead bees clustered around what “was” brood but has long since died.

Cause of Death: Starvation– The bees simply ran out of resources to eat. This can happen any time of year, but primarily at the end of Winter and early Spring (March.)

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Hive Condition: Dead bees with no evidence of old brood

Cause of Death: Failing Queen in late Fall/early Winter. If your Queen wasn’t laying sufficiently in the later Fall months, you lacked the workforce to stock up on resources, warm the hive during cold weather, feed larvae, as well as groom and feed her. In Spring, Summer & Fall – the colony will quickly die with a failing queen simply because of no eggs being laid; no eggs = no nurse bees = no foragers = no food!

Another Cause of Death could be: Varroa– High Varroa Mite loads can and WILL cause your colony to die. Typically, your indicators were prior to death and are now long gone now because of the decay of the colony. Testing and Treating for Varroa is CRUCIAL for survival ALL YEAR, EVERY YEAR!

Photo credit: Annalisa Mazzarella

Hive Condition: Few bees milling around; may or may not still have a queen present along with an overwhelming bad fermented odor as well as little “worms” (looks like maggots) crawling in and around the cells.

Cause of Death: Small Hive Beetle infestation has overtaken the hive.

Small Hive Beetles are a part of our everyday beekeeping life, but when not controlled they can and WILL cause your colony to abscond (leave) or die a slow miserable death. Staying on top of SHB is truly one of the easiest tasks we face. It doesn’t require any testing and all effective methods of control are mechanical and don’t require medication or pesticides be placed in out hives.

Hive Condition: Few bees or no bees; “worms” and moths crawling around, cocoons and webbing built on the tops, sides, and faces of frames.

Cause of Death: Overrun with Wax Moths because of Neglect

Yes, I said it… Neglect! Wax Moths are opportunistic – meaning, if they are allowed to come in and take over where the bees had previously been, they will completely destroy old comb and even eat into frames and the boxes. The nasty webbing mess is completely preventable. When you have a colony in decline, ideally address the problem immediately. If it’s obvious the colony isn’t going to make it, break the box down and store the equipment for future use. A dead out left in your bee yard will quickly turn into trash if not addressed.

Photo credit: Dodie Stillman

“The problem starts when we DON’T react to a situation, then a month later we are faced with the reality that our colony didn’t recover without our intervention.”

Hive Condition: Some dead bees or No dead bees and no resources.

Cause of Death: Robbing– If the rims of the resource cells (honey/nectar) appear to be ragged or torn and you find a lot of wax debris on or below the bottom board, the colony probably didn’t die of starvation but instead was robbed of all of its resources. This most often doesn’t happen to “strong colonies” but rather colonies with reduced populations due to virus, diseases or failing queens (causing decreased population.)

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Another Cause of Death could be: Queen failed– The queen was present but stopped laying; if left unnoticed the colony was doomed. With no new brood to carry on, they had no new house bees to clean cells, warm the brood nest, feed larvae, feed and groom the queen, build wax, ripen nectar, or guard bees to protect the colony. In turn no bees aging into foragers to bring in resources for the colony to survive.

IF – You spot an excess of dead drone brood cells (capped or not) it is possible your queen became a “Drone layer.” What is this? A Drone laying queen means, at some point she ran out of sperm; either she wasn’t mated well or she simply aged out (ran out of sperm).                        

Either way when this happens the colony is hopeless. Recognizing they need to replace the queen, the workers have no “fertilized” eggs to make a Supersedure or Emergency cell at this most crucial time. Colony ultimately dies.

Photo credit:Bee Informed Partnership

Cause of Death could be: Absconding (the colony left) Often when colonies are sick and failing, starving or have high mite loads, they will just leave! Would you live where the conditions are so bad you can’t stand to stay? Odds are those bees didn’t survive long once they left but they really didn’t have a choice…die if we stay, die if we go.

Hive Condition: Some bees still milling around but Queen long gone, no brood or bad/sick looking (white, black, shriveled) dead brood, maybe an overabundance of nectar but no nurse bees present

Cause of Death: Possible disease or virus present– When a colony dies from disease it can be very difficult to pinpoint the cause. Your “evidence” is most likely gone by the time you find the dead out. BUT – it is very important to know the most common among those we experience. It would take a small novel for me to list the description and explanation of the viruses and diseases Honey Bees are subjected to. For a very good reference guide CLICK HERE to learn more.

Note: Most viruses and diseases are preventable by controlling Varroa Mites. To learn more about Varroa Mites and how to stay ahead of them CLICK HERE.

Another Cause of Death could be: Swarming - Yes, swarming can cause death of a colony! When a colony prepares to swarm, “in theory” they will create a viable queen cell (Daughter Queen.) Depending on how many swarm cells were produced and how well they were fed has a huge bearing on the viability of the “queen left to take over!” OR – the daughter queen left to be mated and never returned, leaving the remainder of the colony that didn’t swarm to fend for themselves, often with bad results.

Hive Condition: Dead Bees on the bottom board (moist and rotting)

Cause of Death: Moisture– If the colony didn’t have sufficient ventilation in the Winter, condensation can occur. Water vapor rises; as it condenses and chills it will then drip back down on to the bees and cause them to chill/freeze. Mold and mildew is also a problem with an overabundance of moisture. It won’t likely kill the bees but makes for a very poor environment for your colony and they will often abscond if left unresolved.

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Hive Condition: Dead Bees inside the box, on the bottom board, on the landing and on the ground in front of the hive

Cause of Death: Possible insecticide, herbicide or pesticide poisoning

A good indicator that bees have been exposed to poison is evident if you find a bee dead with her tongue sticking out. Sometimes a kill can be over a period of time if the bees simply foraged in an area recently sprayed. In this case, the forgers may die off slowly and/or carry the poison into the colony causing a rapid kill.

There are so many “if’s, and’s and but’s” in forensics of a hive. BUT – truthfully, it all boils down to 1 BIG point – Doing regular hive inspections and staying on top of the condition of your bees!

When we do the bi-weekly checks and quarterly Hive Inspections on our bees, we are able to see if something needs to be addressed. The problem starts when we DON’T react to a situation, then a month later we are faced with the reality that our colony didn’t recover without our intervention.

Education is the best gift you can give your bees – commit to taking every opportunity to further your education through club meetings, seminars, webinars and in-person classes. The joy of being successful at keeping healthy thriving bees will far exceed the cost of time and money.

Happy Beekeeping!

Chari Elam

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