Drone laying workers

Chronically queenless, and hence broodless, colonies can develop egg laying workers ^†. Since these workers are unmated the eggs are haploid so develop into drones, therefore explaining the usual term ‘drone laying workers‘ (DLW). Without intervention these colonies are doomed and can be problematic to deal with, particularly if you only have one or two hives. It’s not the absence of the queen but the absence of open brood that allows the development of DLW’s. This is because pheromones produced by open brood usually suppress the egg-laying activity by workers. For a variety of reasons – lousy conditions for queen mating, failed colony uniting, balled queens, dodgy record keeping – I’ve had several colonies developing DLW’s this season so have (unfortunately) had to investigate ways to deal with them effectively.

Diagnosing drone laying workers

The two characteristic symptoms are spotty drone brood appearing in worker cells and multiple poorly placed eggs in individual cells.

The brood pattern is spotty because, unlike a drone laying queen (DLQ), there are usually multiple laying workers in the colony, each laying at random. This contrasts to the clustered brood pattern seen with a DLQ. Secondly, eggs laid by DLW’s are often located on the sides or edges of the bottom of the cell, rather than centrally. In addition, DLW’s often lay multiple eggs per cell and you can sometimes even see 2-3 young larvae developing together. Not shown in the photograph, but also characteristic of DLW’s (and shown nicely in a photograph here), is eggs laid on top of pollen already stored in the cell.

Recommended solutions for drone laying workers

The key point about a colony with DLW’s is that they ‘think’ they’re queenright. If you add a frame of eggs and young larvae they may well not raise queen cells. Therefore the usual test for queenlessness – queen cells generated from young larvae – gives misleading results. If you add a mated queen they are likely to kill her. If you unite the colony with a weak queenright colony – such as a small nuc – they may well again kill the queen. This makes ‘curing’ a colony with DLW’s problematic, particularly if you have only one or two hives.

If you have many colonies, don’t need and don’t want the bother of trying to ‘save’ the DLW’s then the solution is simple … move the hive from it’s original location, shake out all the bees in front of other strong colonies, distribute the frames to other colonies in the apiary and go and get a cuppa. Job done.

But I’ve only got two colonies …

However, I suspect many readers don’t want to reduce their colony numbers in this way and would like to consider alternative solutions. You’ll find a range of ‘fixes’ in books and online, including:

• unite the colony with another
• add a frame of open brood every few days until they start generating queen cells
• shake the bees out some distance away and requeen those that return to the original site

Of course, the first of these still reduces your hive count (!). However, you can certainly unite with a strong nuc successfully. I’ve used this method, but am only really confident if the queenright colony is good and strong.

Adding a frame of open brood effectively adds the brood pheremone that suppresses ovary development and egg laying by DLW’s. You can tell when it works because the colony will attempt to raise queen cells i.e. they now consider themselves queenless and are trying to fix things. At this point you should be able to requeen them if you can get your hands on a spare queen. Alternatively, let them raise their own if the weather permits. However, adding frames of open brood is expensive in valuable resources – if you only have a couple of colonies you might rescue the DLW colony, but you definitely will weaken your other colony. Remember that strong colonies collect more nectar, overwinter better and build up faster in Spring … despite the maxim that two colonies are better than one, at many times of the season you’re better off having one strong colony rather than two weak ones.

Finally, what about moving the colony away, shaking them out and requeening the workers that return? The principle here seems to be that the DLW’s will not or cannot return to the hive. Therefore shaking them out reduces the DLW’s either because they are younger bees that have yet to go on orientation flights or older bees that are, for whatever reason, just less able to fly well.

But they can fly …

However, my experience suggests that at least some DLW’s are able to fly perfectly well. The image of the eggs right above was taken three days after shaking out a colony ~100 yards (or 91.4 metres in pre-Brexit measurements) away. These eggs were in the middle of a frame of drawn comb with some stores, flanked by frames of foundation. This colony contained a lot of DLW’s (an assumption from the levels of drone brood present in the original hive) some or many of which could clearly fly.

I ended up shaking this colony out and walking away … for a cuppa.

This summer I’ve started using a composite method to ‘rescue’ DLW colonies that seems to get reasonable results. Importantly, it achieves this without excessive delay, without using up multiple frames of open brood and without reducing the colony number. I’ll write something about this next week.

† actually there are usually a few laying workers in every hive … these probably account for the rare single drone pupae developing in the honey supers that are sometimes seen.