Queen cell size

[fatshark]

I've not seen this discussed before and wonder what others think …

We ran a queen rearing practical course on Saturday, with about 8 people doing grafting for the first time. The lighting wasn't great and some were struggling to see suitable sized larvae. In parallel an experienced colleague grafted from a 'sister' frame from the same colony.

My expectation would be that the experienced grafter would choose smaller larvae, whereas the beginners were more likely to choose ones that were a bit too big. The two cell bars went into different "Ben Harden" cell raisers.

I checked the cells again this evening. Take was better by the experienced grafter (~80+% of 18). However, the beginners did reassuring well (~50% of 18). However, all the drawn out cells by the experienced grafter were appreciably shorter. All the cells I looked at were pretty well charged with Royal Jelly, but (again) the lighting wasn't good enough to check the larvae size.

After all that … is cell size an indication of the age of grafted larvae? Could you use this an an indication to choose the youngest larvae which should end up the best fed?

I don't think it's anything to do with too few bees in the box with the higher take. Both are pretty busy.

[mbc]

struggling to see suitable sized larvae.

I always think I've picked larvae that are too old if I can see them clearly.
The differing cell sizes could be down to the cell raisers rather than age of larvae. If you have a bar of queen cells its fairly self evident which ones, if any, should be culled- they will differ from the norm. I usually cull if cells are smaller than their neighbours or look malformed in any way, some breeders "candle" their cells but I've not learnt the trick.

[Jon]

I would agree with MBC. The difference is probably something to do with the cell raiser colony rather than the size of the larva selected.

[fatshark]

OK, I'll check them every day and see if there's a difference in when they're sealed.

Although it's not 'candling' a commercial friend of mine always uses JzBz cups. By holding near to emerging cells against the light he can tell - through the semi-translucent base of the cup - which have ample jelly left. Those that don't he discards, reasoning that they haven't been well fed.

[prakel]

Joe Latshaw makes some worthwhile observations on larvae size in his pdf 'Queen Rearing Basics' I reckon that this is one of those should-read documents for anyone starting raising queens of their own.

[fatshark]

Thanks prakel … I see that Latshaw makes a similar case as my bee farmer friend re. amount of jelly left.

Re. stabilising the colony … not heard that one. When using mini-nucs I always remove the vacated cell the day after emergence (just so it doesn't get all jammed up) - they've usually been cleaned out by then though.

[Kate Atchley]

Joe Latshaw makes some worthwhile observations on larvae size in his pdf 'Queen Rearing Basics' I reckon that this is one of those should-read documents for anyone starting raising queens of their own.

Thanks for pointing us to this doc Prakel. I hadn't come across it and Joe Latshaw includes a pic showing the plastic cup full at the base of the queen cell. I hadn't focussed on this before but ... well of course! Will also try candling natural cells (which I do routinely when incubating hens' eggs).

In this pic showing the filled cup beneath the pupae, the wax cell extends down about 2.5 times the depth of the visible part of the plastic cup - i.e. total length is about 3.5 x plastic cup depth or 2cm. Would others regard this as roughly 'standard'? It's smaller than many I've reared and some have been smaller.

Hoping to achieve good mating this year as we've had some good spells of fine weather here in the west.

[prakel]

Although it's not 'candling' a commercial friend of mine always uses JzBz cups. By holding near to emerging cells against the light he can tell - through the semi-translucent base of the cup - which have ample jelly left. Those that don't he discards, reasoning that they haven't been well fed.

There's a theory which I've come across somewhere in the past that not removing the cell after emergence helps to stabilise the colony while the virgin is waiting to mate by allowing the remains of the jelly to be fed back into the colony. No, I don't have any references to research on the subject, it's just 'stuff' that I've heard mentioned but I suppose that if there is anything in the idea then the more jelly left in the vacated cell the better.

[HJBee]

Is there a greater risk of her getting through an excluder if she is petit?

[Jon]

I have never seen queens pass through an excluder - even very small ones.
Reading some of the online bee forums you would think queens got through the excluder on a regular basis but it is much more likely to be operator error imho.
A small queen can lay up an entire brood box no problem if she has mated well.
The problem is that even the most raw beginner who knows nothing of queens or queen rearing is likely to make some comment about size even if the queen is actually a good one.