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Moeuk
04-06-2008, 07:25 PM
I have been asking this question on different forums, and have come up with some really strange answers.

The question is;
With a normal hive with everything being as it should bee, we find that 99% of the bees that forage die away from the hive. Why do they die away from the hive instead of dieing in the hive?

Disscount any preditors.

Is it genetic?
Is it through wear & tear?
What happens to their metabolism when they know they are going to die?
Or do they suddenly die quickly?

Looking forward to some suggestions.

Moeuk.:eek:

Ravenseye
04-06-2008, 07:48 PM
I go with wear and tear. An old forager loads up with nectar or pollen, struggles to get airborne, fights wind and distance, perhaps cold and simply runs out of gas. Two years ago I was researching a paper while sitting in front of the hive. A bee hit my leg and fell to the ground. I watched and waited as she crawled around, then hovered an inch or so off the ground. I picked her up and found her wings completely frayed. She hardly moved. I went in the house, put a drop of honey on my finger and let her take some. Within a couple of minutes, she took off, circled a few times and then clumsily made it to the landing board. I think she was out of fuel, having worked so hard to make it back. The morning temps weren't the best either. I probably saw her last flight home.

Moeuk
04-07-2008, 08:05 AM
Hi Ravenseye,:)

Thanks for the response.

I go with wear and tear.

Ok I do understand that wings being frayed and tattered causes loss of flight, but loss of life? Doubt that very much.

I think we need to go deeper into the make-up of the bee to find this answer. I wonder if like us, their whole genetic structure begins having difficulty in reproducing the cells and other 'matter' which keeps them alive?

I have tried many sites on the web, without much success, and even e-mailed Dr. S Colby, and she could not explain why the bees die away from the hive.

We are told the whole story from the concept of the production of the egg, the fetilisation etc all through to foraging. After that its, 'the foragers die away from the hive as they can not make it back'. WHY?:confused:

I wonder if we will ever know the answer.

Moeuk.:eek:

Jim Fischer
04-07-2008, 08:44 AM
Each point can be answered "yes", but in general, bees that are sick
DO leave the hive if they can. This is instinctive, and it protects the
rest of the hive from whatever the bee has picked up.

I do not have a specific textbook citation or study of the behavior to
point to, but here is a decent quote from before CCD was an issue,
when the honey bee genome was sequenced:

http://www.newscientist.com/article.ns?id=mg19225754.000 (http://www.newscientist.com/article.ns?id=mg19225754.000)

Keith Jarrett
04-07-2008, 09:02 AM
nosema. :(

Moeuk
04-07-2008, 09:39 AM
Hi Keith,

Nosema? Possible but with all the young house bees cleaning up and passing the spores onto other bees by feeding, then in theory they should starve and die in the hive. So not too sure about that idea.

Anything and everything is possible I suppose.

Moeuk.

Keith Jarrett
04-07-2008, 10:34 AM
Hi Keith,

Nosema? Possible but with all the young house bees cleaning up and passing the spores onto other bees by feeding, then in theory they should starve and die in the hive. So not too sure about that idea.
Moeuk.

Moeuk, I dont think so...

I think with nosema, the young bees do fine but, what happen's is the life span is shorten with nosema and the mortally rate to hatching rate ratio is at a loss of growth rate.

Starve & die in the hive.....

I think with nosema the bees just shrink down to nothing, no big sign of loss, in front or inside the hive.

I think folks should key in on nurtrition. :)

Kieck
04-07-2008, 10:45 AM
With a normal hive with everything being as it should bee, we find that 99% of the bees that forage die away from the hive. Why do they die away from the hive instead of dieing in the hive?

Disscount any preditors -Moeuk

I think "predation" needs to figure into the equation.

Looking at all the causes of mortality to individual bees, and considering the odds of those causes, most bees will die away from the hives simply because so many of the causes are much more likely to occur away from the hives.

Some of those causes: predation (spiders, flies, birds, dragonflies, reptiles, amphibians, mammals, etcetera), pesticide poisoning, impacts (cars, trucks, humans, other animals, etcetera), weather (freezing, chilling, soaked and drowned, hail, etcetera), and progression through various duties (bees work as "house bees" before turning to foraging).

My guess is -- I haven't seen any well-built life tables for individual honey bees -- that predation and immeidate damage from environment are the largest causes of mortality among bees, and relatively few bees simply die of "old age."

Moeuk
04-07-2008, 12:52 PM
Thank you all for your replies.

Hi Kieck,
In response to your post, we know there are losses from predation, but I do not think it is to the extent to which you refer.
As for pestacide poisoning; the resadue from the chemicles that are sprayed will be bought back to the hive by the foraging bees. This will intern be passed onto the 'house' bees, which intern will pass on the chemicles to the brood and eventually it will kill the whole hive. This is somewhat different to bees dying away from the hive.

You mentioned weather, to a degree I can understand that bees caught out in torrential rain might become disorientated, but on saying that the bees know the weather better than we give them credit for. Cold does not kill the bees, it can kill the larvea if there are not enough bees to keep the brood warm enough. So I don't think weather is a contributing factor.



My guess is -- I haven't seen any well-built life tables for individual honey bees -- that predation and immeidate damage from environment are the largest causes of mortality among bees, and relatively few bees simply die of "old age."


Sorry Kieck, I just don't see that. Some will die in the immediate environment but I still think the majority of bees die away from the hive, but I don't know why.

Thanks for the input, its appreciated.

Moeuk

Kieck
04-07-2008, 06:49 PM
In response to your post, we know there are losses from predation, but I do not think it is to the extent to which you refer. -Moeuk

OK, but I suspect you're wrong. My reason for thinking that is that virtually every life table that I have seen for insects ends up pinpointing "predation" as the largest or one of the two largest causes of death for individuals. Keep in mind that doesn't account for entire colonies of eusocial insects, just individuals of different insects. None of the life tables that I've seen have been prepared for honey bees; I just cannot fathom that honey bees are so different than other insects that their life table would differ so greatly. I'd be curious to see something to either support or refute my hypothesis, other than sheer conjecture.


As for pestacide poisoning; the resadue from the chemicles that are sprayed will be bought back to the hive by the foraging bees. -Moeuk

Many of the insecticides in use will kill foraging bees before the bees return to their hives. Your statement is accurate, I believe, for low concentrations of chemicals, but many contact insecticides are in use. Those almost certainly kill a significant number of bees before the bees get back to their hives. (Just as a side note: some of the insecticides that I've applied in the past were/are potent enough to drop mice entering the sprayed area within the first 48 hours after application. If they're strong enough for that, they're strong enough to knock down bees, too.)


Cold does not kill the bees,. . . -Moeuk

Sure it does. Just as an example, we had a day about five or six weeks ago that warmed up to 38F. Literally thousands of bees from one of my hives flew out on cleansing flights. I doubt very many made it back to the hive. Workers were dropping to the snow and slowing down all around the hive. Thousands of bees froze on the surface of the snow that day from that one hive.


Sorry Kieck, I just don't see that. -Moeuk

That's fine. I suspect that it's about right, though. Think about it like this:

Start with a newly emerged adult bee. As a house bee, the factors that are likely to kill that bee are relatively few. Let's just say, for the sake of saying a number, that 99 percent of house bees survive to become foragers.

Now, let's say that the average forager has a 10 percent chance of falling victim during the course of its life to a predator. And a forager has a 2 percent chance of smashing into a car, a 5 percent chance of dying from some weather event, and a 2 percent chance of dying from pesticide poisoning. We're down to a little over 81 percent chance of surviving all that.

The problem is, for most insects, predation takes a significant percentage of individuals, often 30 to 90 percent. I'll try to find some information on honey bees.

okb
04-07-2008, 07:01 PM
On average 100 bees die per day Inside the hive.

trapperbob
04-07-2008, 08:44 PM
A bee takes with it enough fuel to get to where it is going so that it can forage if it dose'nt take enough well it's done for,it may just just fly itself to death,it may finally wear its wings out or a dozen other things I'm sure of one thing it's not just one cause. When you have that many bees out at one time the odds of all of them surviving would be amazing. Heck at the right time of year the swallows hang out on the trees and sun flowers by my bees and dive through the lines of bees flying back and forth. I don't know how many bees one of those little birds can eat but a whole colony of them lives in the land owners barn and the bees amaze me by overflowing the hive and out producing there stomachs.

SemoraBee's
04-07-2008, 11:42 PM
I am having a similar problem with adult bees dying. The ground in front of on of my hives is littered with hundreds of bees every day. Some as far as 8 feet away. Not a strong hive but very active bringing in pollen. I have no other hives in this area as I cannot make a comparison, however, I have not seen this problem with other hives miles away. I suspect pesticide as I live next door to a high school baseball field and they may have sprayed for grubs or other pests. Thoughts ???

Moeuk
04-08-2008, 10:47 AM
Hi Kieck,
Many thanks for you reply, I find this fasinating, sharing each others thoughts.

You mentioned about 'Life Tables' for insects, and that you have not come across one for honey bees, I must admit I never thought about looking for that kind of information. But will do now.


OK, but I suspect you're wrong. My reason for thinking that is that virtually every life table that I have seen for insects ends up pinpointing "predation" as the largest or one of the two largest causes of death for individuals.

Right, lets say a queen lays 1000 -1500 eggs per day during the season when everything is going smoothly.
We'll work on the figure 1,000. So over a three week period she will lay 21,000 eggs, and in three weeks the first 1,000 bees will be ready to forage. Also bear in mind the bees that are allready foraging.
So over a three week period there should be about 20-21 thousand bees foraging befor the first batch we mentioned starts to die off.

Kieck, I just can not see that 'preditation' will knock down a large % of these bees. The figures I have mentioned are for one hive, multiply that by the number of hives a person has and we are talking of thousands & thousands of bees out foraging.

I know in UK the predation is a minor problem.


Sure it does
Yes I agree with you on only a minor point here. Perhaps I should have written it better, as what I wanted to say is the cold does not kill bees whilst in a cluster in a hive. Sorry about that.

If you can come up with info regarding how bees die then I would like to hear it. Also if I find anything about this sbject I'll get back to you.

Many thanks for your comments and I wonder how much more info we can pass to each other?

Best regards

Moeuk.

Moeuk
04-08-2008, 11:02 AM
Hi Semora,

You seem to have a problem there.
Is it possible for you to send a sample away to a laboratory for testing for pestacides?

Here in the UK if poisoning is suspected then a sample is sent to our National Bee Unit where it will be analyzed for pestacides, if there are chemicles found which are not permitted then the person spraying will be prosicuted.

Another thought it might be Nosema.
Do you know how to check for Nosema? If not ask at your local association, someone there will know.

Good luck

Moeuk

Kieck
04-08-2008, 11:51 AM
You mentioned about 'Life Tables' for insects, and that you have not come across one for honey bees, I must admit I never thought about looking for that kind of information. But will do now. -Moeuk

I have found references to one. I am trying to obtain a copy of the paper that contains the life table. From the citations made for this paper, I believe that the life table is fairly incomplete, but that's to be expected.

The problem, of course, is assigning causes of mortality to foragers. Honey bees in observation hives can easily be marked, and observed, so data for longevity of workers is readily available. The problem, though, is determining the fate of those workers when they fail to return. Were they eaten? Did they simply fail to return because their wings were tattered to a point where the bees could no longer fly? Were they hit by an automobile on the highway?


Right, lets say a queen lays 1000 -1500 eggs per day during the season when everything is going smoothly.
We'll work on the figure 1,000. -Moeuk

The papers I've found that try to assign some probabilities to survival at various stages, suggest relatively high mortality among eggs and early instar larvae of honey bees, then increased probabilities of survival until after a certage age as adults. So, to suggest that a queen will lay 21,000 eggs in a three-week period seems reasonable, but to suggest that 21,000 workers will result from that egg-laying, I think, is expecting a bit much. Let's say the brood pattern is good (fairly solid) -- maybe 95 percent of the cells end up capped. That would result in 19,950 pupae.

A couple papers I've found contain some interesting information. One demonstrates, statistically, that workers live for the same number of days after eclosion (emerging as adults), regardless of the number of foraging trips made. The researchers confined some workers in a hive, restricted the foraging trips of some other groups in the same hive, and allowed some unrestricted foraging. The number of trips made by the different groups varied significantly. The number of days that they survived as adults did not differ significantly.

Another paper described mortality rates of drones. The mortality rate of drones in positively correlated to the number of flights taken by the drones. The authors suggest that the risks encountered on the flights are likely responsible for the losses.

I have studied some of the predatory insects that feed, at least occasionally, on honey bees. Some of those predators can and will consume one bee per hour, and some seem to hang around bee hives opportunistically (why wouldn't they? with a nice, ready source of food, it just makes sense). Let's say that you had 10 of these predators around a hive (not unrealistic; I've encountered many situations with far more than that), and let's say that each successfully kills one bee every two hours; that works out to 60 bees per day just lost to the predators right around the hives. Then you factor in the crab spiders that camouflage themselves in flowers, the true bugs waiting on flowers for visiting insects, the dragonflies and other predators encountered on travel to and from the hive, etcetera, and the number likely lost to insect and arachnid predators is significant.

And that still does not account for losses to birds, mammals, reptiles and amphibians.

I'll be interested to hear from you, Moeuk, about any life tables you might be able to uncover!

France
04-08-2008, 06:18 PM
[QUOTE=Kieck;
Sure it does. Just as an example, we had a day about five or six weeks ago that warmed up to 38F. Literally thousands of bees from one of my hives flew out on cleansing flights. I doubt very many made it back to the hive. Workers were dropping to the snow and slowing down all around the hive. Thousands of bees froze on the surface of the snow that day from that one hive.[/QUOTE]


I will try to push this on a right track, if I may?

Those bees on a cleansing flight, on that nice 38F day, did not "Froze" and did not even die that day!

Bees are cold blooded. When chilled, they stop, fall, can't fly, or what have you.
In old days it was customary to spread straw, hay, sawdust, etc., around the bee yard, so when the bees get chilled - they don't fall in the snow - where they will surely be lost. Even if there is no snow on the ground, a caring beekeeper will not have hives placed on cement, stones or rocks - cause bees will set on them and get chilled, their return to the hives will be cut short.
I know?!
Who has time for such thoughts, much less doing it in this day and age?
If next day the sun warms those bees up, they may make it back to the hive.
One can pick "seemingly dead bees," from the snow and warm them in ones hands and in a minute or two they will come to life.
That is a fact!

(in Europe, to this day, beeks throw a shovel of snow on the entrance, to discourage bees from leaving the hive on such days. At the same time they provide much needed water, so bees don't have to brave the elements and get lost...)

Such bees, which for one reason or another end up in the snow, will after a day or two, or three, die ! But not from cold or "froze" - but from starvation!
Same as in the cluster. There they rotate and are fed - although to a lot of newbies they appear dead and are cleaned out of hives - to certain death. . . .

(Just last week, on a diferent forum a beek was writing how he/she thew dead bees in a thrush can, while crushing and straining recovered combs.
After a while, the beek was amazed that dead bees started crawling all over the house and was for couple days catching them and flushing them down the toilet!?)
Sad!?
Cause bees are to most - merely "bugs," such deeds even draw a laugh or two. But mistreat a barn-animal or a house pet like this, than the story will warrant global attention. . . .

Well, I hope that with my rumbling, I managed to shed a bit of light, on the dead and not so dead?


Regards,
France