Do bees transfer eggs? – The Apiarist

Synopsis: How do eggs seem in puts the queen can not achieve?  Do those eggs produce employee or drone brood? If bees can transfer eggs, can they transfer them to queen cells?

Advent

There used to be numerous pastime within the publish remaining week, and I’d love to thank readers who commented or contacted me at once . Additional posts at the matter will seem ahead of queen rearing begins in earnest (or no less than right here in Scotland 😉 ).

Within the research I described remaining week, the queen used to be trapped on a specifically changed body at the back of a queen excluder.

Most likely extra as it should be on this example it will have to be referred to as a queen includer because it avoided the queen transferring in other places within the hive.

As a result, we will be able to make certain it used to be the queen that laid the eggs at the changed body.

Or are we able to?

Sure, we will be able to .

Within the explicit research described remaining week, the eggs hatched, the larvae advanced, pupated and emerged as new queens. With one exception (Apis mellifera capensis – see underneath), employee bees can not produce feminine progeny … and the ensuing queens I described remaining week have been undoubtedly feminine.

Alternatively, in analogous instances, there are eventualities during which eggs seem in places that the queen can not achieve.

How do the eggs get there?

Apis mellifera capensis

Let’s in short handle that exception first. The Cape honey bee (Apis mellifera capensis or, for comfort, Capensis) from South Africa.

Surprisingly, Capensis staff can lay unfertilised eggs which become diploid feminine staff. Inside a colony, as much as 50% of the Capensis staff can lay eggs, and this has profound implications for honey bee biology. For instance, those eggs will also be reared as new queens.

The manufacturing of feminine diploid progeny from unfertilised employee eggs happens via a procedure termed thelytokous parthenogenesis . There may be some advice this developed in Capensis to atone for the top lack of queens on mating flights within the – famously windy – Western Cape area of South Africa.

With out those worker-laying staff, or extra as it should be, diploid feminine laying staff, a colony that misplaced a virgin queen on a mating flight can be doomed.

Thelytokous parthenogenesis lets in the rescue of an in a different way terminally-queenless colony.

While I’m positive some readers are wishing their bees had the similar ‘get out of prison loose’ trick, and others are questioning why the trait isn’t found in all traces of Apis mellifera , I’m going to transport unexpectedly on as I chance disappearing down a rabbit hollow of relations variety, social parasitism and gene GB45239 which – by myself – accounts for the thelytokous phenotype.

Employee laying staff

When you’ve saved bees for quite a lot of years you might be most probably aware of the irritating factor of laying staff. Against this to the Capensis worker-laying staff described above, commonplace laying staff lay unfertilised eggs which move directly to become haploid drones.

All colonies include a low percentage of laying staff … they account for most likely 0.01% of the employee inhabitants. Visscher (1996) demonstrated that ~7% of the unfertilised (male) eggs in a colony have been laid via staff, no longer the queen. Alternatively, research of the grownup drone inhabitants (in a queenright colony) confirmed that just one in 1000 (0.1%) have been worker-derived.

Those observations let us know two issues of relevance to the subject of whether or not bees transfer eggs:

• some eggs produced in a colony are laid via staff, no longer via the queen
• the majority of worker-laid eggs are got rid of, or no less than don’t become grownup drones

Research courting again to the past due 80’s decided that staff can not discriminate between larvae created from eggs laid via queens and the ones from eggs laid via staff. This and different proof helps the life of a policing mechanism – termed employee policing – during which eggs no longer laid via a queen are got rid of (and typically wolfed) via staff.

Employee policing explains the very small numbers of drones that originate from eggs laid via staff. I’ll talk about the mechanism during which staff differentiate between queen- and worker-laid eggs at another time, however it’ll be a marvel to completely no-one that it comes to queen pheromones.

Eggs in bizarre puts

Queens are creatures of dependancy. They’re hardly discovered clear of the brood nest. When you discover a queen scuttling round on frames of shops at the outer edge of the brood nest you’ll be beautiful sure that you just’ve disturbed her via over-smoking the colony, or via being slightly hamfisted when taking away or returning frames throughout an inspection.

Decelerate … take into accout, extra haste much less velocity.

On just right comb – during which I imply lightly drawn comb no longer already part-filled with nectar or pollen – queens have a tendency to put in concentric circles, generating rings of similarly-aged eggs, larvae and pupae. Conversely, they generally tend to not lay particular person eggs on the excessive outer edge of the brood nest, or in frames in a different way full of shops.

And so they truly battle to put above the queen excluder.

So why is it no longer atypical to search out eggs, larvae or pupae in tremendous frames?

Virtually any time I extract greater than a half-dozen supers I anticipate finding one or two pupae there. If those are drone pupae – like the man above – then the most obvious clarification is that it’s an egg from a laying employee that escaped employee policing.

Alternatively, officially it is usually a drone egg moved up via a employee from the brood nest into the tremendous.

Drone pupae are simple to give an explanation for.

Against this, eggs, or employee pupae or occupied queen cells are both uninterpretable, or require a greater clarification. And, on events, you’ll in finding those within the supers as smartly.

Anecdotal reviews

There are reviews going again no less than to the start of the nineteen^th Century on eggs showing in places the place the queen has no get admission to. It’s price remembering that those reviews pre-date any working out of employee policing, regardless that laying staff had already been ‘seen’ and described via Francis Huber .

A piece of writing in Bee International from 1936 describes eggs showing in comb out of achieve of a queen; as an example, in a hive during which the queen is tethered to a selected patch of comb (see additionally the experiments via Butler underneath), or in frames adjoining to a queen trapped in a cage. A number of of those reviews additionally describe bees sporting eggs.

Alternatively, a lot of these in large part anecdotal reviews contain employee brood, and many don’t exhibit the eventual emergence of the employees.

The creator of the Bee International article even means that some eggs on the outer edge might be behind schedule in hatching because of their being in a fab a part of the brush. That’s a fascinating advice and no longer one thing I do know a lot about. I comprehend it’s conceivable to ship eggs via publish and presume the decreased temperatures there equally delays hatching.

A lot more fascinating than transferring eggs to rear employee brood is the chance that staff may transfer eggs into lately produced queen cells. Thankfully, there are some clinical research carried out on this space which assist deal with the unique query of whether or not bees transfer eggs.

Medical research of the origins of eggs in queen cells

In a queenright colony, the queen is going about her trade laying eggs in employee and drone comb.

If the colony is overcrowded and making swarm arrangements, it’s presumed that the queen – encountering a queen cup in her travels – additionally lays an egg within the queen cup. A number of reviews describe this taking place in research the usage of remark hives.

Supersedure

If the queen is failing, via harm or outdated age, the colony would possibly attempt to supersede her.

Colin Butler (1957) reasoned that each harm or outdated age may prohibit the mobility of the queen, and that both of those may induce supersedure.

Butler due to this fact investigated the manufacturing of queen cells in a colony during which the queen used to be tethered via an excessively skinny cord looped round her petiole (the slim waist that characterises member of the Hymenoptera).

This tethering avoided the queen from laying in cells, regardless that she may nonetheless drop occasional eggs at the floor or rim of the drawn comb. Butler provisioned the hives containing the tethered queen with frames of younger larvae from which they have been anticipated to rear supersedure queens (if, this is, limited mobility did certainly induce supersedure).

Seventeen of 42 colonies containing tethered queens produced queen cells; 12 of those 17 have been vintage emergency cells, with the mobile being drawn from employee comb. Alternatively, the rest 5 colonies had queen cups containing eggs.

Because the queen may no longer achieve the queen cups (because of her being tethered) the eggs should were positioned within the cups via staff.

Had been they laid within the queen cups via laying staff, or have been they eggs laid or dropped via the queen and moved to the cups via staff?

Butler suggests the latter, pointing out that there used to be no proof of laying employee job within the hives (and plentiful open brood will have to suppress this job anyway).

Alternatively, sadly we’ll by no means know. Now not simplest have been the experiments carried out 70 years in the past this summer time, however Butler didn’t let the eggs hatch, expand and emerge. The tethered queens have been launched quickly after queen cells have been produced, and all colonies tore down the queen cells.

The emergency reaction

If the queen is killed or got rid of from the colony, the ‘emergency reaction’ leads to staff rearing a number of substitute queens from eggs or very younger larvae.

Queen rearing beneath the emergency reaction is quite simple to check. Additionally it is the root of nearly all of queen rearing strategies utilized by beekeepers.

There are two comparable research via Mark Winston (like Butler and Huber, some other of the exceptional honey bee researchers upon whose research numerous our recently working out of honey bee biology is based totally) which are related to the query “Do bees transfer eggs?”

Those papers (Winston, 1979 and Punnett & Winston, 1983) deserve a complete publish of their very own as they’re weighted down with fascinating observations of what occurs when the queen is got rid of from a colony. That is related to sensible beekeeping … what do you suppose occurs while you habits a break up, leaving one 1/2 abruptly queenless?

The 1979 paper used to be on Africanised bees, the later one on Eu honey bees. In each research, colonies have been de-queened and inspected each day for the positioning, foundation and timing of queen mobile manufacturing. The age of eggs or larvae decided on for rearing of queens used to be decided via ‘counting again’ from the date/time at which any ensuing cells have been sealed.

Africanised honey bees

Queen cells have been produced 1-2 days after de-queening. Those queen cells have been prolonged from employee brood comb, however 47% of them (29/62) have been unoccupied when first elongated. On next inspection, those cells contained eggs or younger larvae, and those in the end advanced into queens and emerged.

There are two vital conclusions from this find out about:

• nearly 50% of recent queen cells in those colonies have been populated with eggs or larvae moved there via staff within the queenless colonies
• those eggs/larvae have been no longer because of laying employee job as they advanced into queens, no longer drones

Eu honey bees

The 1983 repeat eager about Eu honey bees. On this example, all de-queened colonies produced new queen cells inside sooner or later of queen elimination.

Alternatively, against this to the find out about described above, simplest ~5% (5/118) of those queen cells have been empty when first elongated. Even though a smaller share, the importance is identical:

• the eggs or larvae that have been therefore found in those queen cells should were moved there via staff within the hive
• they weren’t laid via laying staff as a result of a) all cells have been occupied via larvae inside 3 days so should were laid via the unique queen, and b) they therefore advanced into viable queens and emerged

I’m no longer positive why there used to be a distinction in brood (i.e. eggs or younger larvae) motion between the Africanised and Eu traces of Apis mellifera. Alternatively, I’m in just right corporate …

The explanations for those other motion charges don’t seem to be transparent (Punnett & Winston (1983) )

… so let’s no longer concern about it.

However what in regards to the glue?

When the queen lays an egg, she attaches it to the bottom of the mobile with a glue-like secretion.

No doubt, if the egg is moved via a employee they will be unable to reattach it as it should be to the bottom of the following mobile?

Smartly, if people can do it, I’m beautiful sure that bees can.

And people can.

Steve Tarber (1961) described a changed set of forceps that may be used to raise eggs and position them in recent comb. About 75% of repositioned eggs would therefore hatch in both a hive or incubator.

The ‘trick’ to the design of the forceps is it appears the presence of ‘flared lips’ which steer clear of touch with the posterior glued finish of the egg.

I’ve completely certainly {that a} employee bee may succeed in a equivalent or higher stage of dexterity.

So, do bees transfer eggs inside the colony?

Sure.

As a scientist, I will not call to mind clarification – instead of employee bees transferring eggs about within the hive – for the consequences offered above.

Preferably, I’d additionally need to apply bees transferring eggs. I’m no longer conscious I’ve ever observed this, regardless that I’ve observed them consuming eggs.

Most likely I will have to get my prescription checked for my studying glasses in preparation for the season forward?

Can bees transfer eggs between hives?

So, if employee bees can transfer eggs inside a hive, may they transfer eggs between colonies?

May a terminally queenless colony be ‘rescued’ via stealing eggs from a neighbouring colony?

A long way fetched?

Most likely, however it has been advised that this happens.

An egg is smaller than a complete pollen basket. I don’t know the density of both pollen or eggs, however I believe the burden isn’t very other. An egg may mess with the aerodynamics of flight – regardless that take into accout bees can fly with a radio antenna sticking out from the thorax – so I believe staff may shipping eggs between nests.

Do they?

I doubt it.

CHCs and relations variety

To assemble the egg, they’d need to run the gauntlet of the guard bees within the ‘donor’ nest, after which negotiate their method into the centre of the brood nest to choose an egg. There are numerous bees in the way in which, and the cuticular hydrocarbons (CHCs) at the ‘thief’ from the (probably) queenless colony would make her ‘odor’ utterly other.

I’m positive she’d be repulsed, or worse, beautiful temporarily.

Robbing bees typically prevail once they weigh down the defences of a weakened colony. That’s an excessively other state of affairs from a unmarried employee creating a bold ‘break and clutch’ raid on a robust hive.

Moreover, I will not see this behaviour evolving for 2 causes:

• a ‘stolen’ queen can be unrelated to the robbing employee; from relations variety idea there can be very little selective force for the trait
• for the same explanation why, if the trait did evolve it could be ‘misplaced’ as quickly because the stolen queen changed all of the bees within the hive.

As at all times, Occam’s razor applies … the most simple clarification is typically the proper one.

Somewhat than predicting the evolutionarily, kleptobiotically and doubtlessly aerodynamically not going robbery of an egg from a neighbouring colony, my wager is {that a} queen mobile showing in a terminally queenless hive would include a drone pupa from an egg laid via a laying employee.

Sensible beekeeping

Are there any implications for beekeeping?

Most certainly none.

If it occurs between employee cells then who cares? It’s simply a kind of hundreds of hidden occasions that move on undetected or unsuspected within the colony on a daily basis.

If it comes to switch of a employee egg to a queen cup, and the ensuing queen is going on to go a colony which produces 60 kg of honey subsequent season, then – once more – who cares?

However what are the consequences for the maternal impact I mentioned remaining week? If eggs may also be moved into queen cups via staff then no less than some queens would possibly outcome from eggs decided on via staff.

If so, there can be no ‘maternal impact’ … until the employee bees know which eggs to switch.

And I wouldn’t rule that out .

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Notes

I posed the next paraphrased query within the advent:

Are we able to make certain that the caged queens used within the Wei et al., (2019) find out about – see the publish remaining week for the reference – laid the eggs within the queen cups within the changed body beneath the queen includer?

In spite of re-reading the paper a number of instances, I will not determine whether or not the different frames within the hive can have contained eggs throughout the 6 hour duration when the queen used to be caged.

In the event that they did, how are we able to be sure that the eggs that therefore gave the impression within the plastic queen cups had no longer been transferred there via staff? Most likely no longer they all, however no less than a few of them?

This may essentially exchange the translation in their effects, and would imply that it used to be the employees that might discriminate between lighter and heavier eggs.

Which, after all, they are able to 😉 .

References

Do Bees Transfer Eggs? (1936) Bee International 17: 74–74 https://doi.org/10.1080/0005772X.1936.11093524.

Butler, C.G. (1957) The method of queen supersedure in colonies of honeybees (Apis mellifera Linn.). Ins Soc 4: 211–223 https://doi.org/10.1007/BF02222154.

Punnett, E.N., and Winston, M.L. (1983) Occasions following queen elimination in colonies of european-derived honey bee races (Apis mellifera). Ins Soc 30: 376–383 https://doi.org/10.1007/BF02223969.

Taber, S., III (1961) Forceps Design for Shifting Honey Bee Eggs. Magazine of Financial Entomology 54: 247–250 https://doi.org/10.1093/jee/54.2.247.

Visscher, P.Ok. (1996) Reproductive war in honey bees: a stalemate of employee egg-laying and policing. Behav Ecol Sociobiol 39: 237–244 https://doi.org/10.1007/s002650050286.

Winston, M.L. (1979) Occasions following queen elimination in colonies of Africanized honeybees in South The usa. Ins Soc 26: 373–381 https://doi.org/10.1007/BF02223556.

Credit

Symbol of Apis mellifera capensis via Discott, CC BY-SA 4.0, by way of Wikimedia Commons.