The Management of Honeybees for Oil Seed Rape

A talk by Lynne Ingram, February 2020

There was a good turnout of East Devon and West Dorset beekeepers to welcome Lynne back for another of her thought provoking talks. A quick show of hands revealed that the majority of the audience viewed oil seed rape (OSR) a curse to beekeeping, a view that Lynne was hoping to dispel.

Today, the crop makes a valuable contribution to the British economy, estimated at more than £650 million. It has in fact been in use for 4000 years and there are records of its use in 1649 for soap and oil production. The domestic market started in the 1950s and got a boost in the 1960s due to the newly perceived benefits of polyunsaturated fats found in rape seed oil.

In addition, the oilseed cake residue was a valuable animal feed. However, it became apparent that the erucic acid content of the varieties used at the time was causing heart damage. This brought about the introduction of low erucic acid varieties through plant breeding.

Another group of compounds found in oilseed cake were the glucosinolates, causing damage to thyroid and pituitary glands of animals fed large quantities of the material. This too was reduced by plant breeding, leading to the current ‘double low’ varieties.
More recently the 2013 ban on neonicotinoids has resulted in reduced plantings of OSR and lower yields.

What is OSR?

All varieties are derived from Brassica napus, a member of the cabbage Family. Winter sown crops will usually flower in mid-April for about 3 weeks whereas spring sown varieties drilled in early April will flower in July. Pollen and nectar are produced in huge quantities, with the added bonus that depleted nectaries are rapidly refilled. OSR can be partially wind pollinated but insect pollination increases the seed yield.

The advantages of OSR are the potential for a large crop of naturally setting, finely crystallised honey which can be used as a ‘seed’ for other honeys that are reluctant to set. Disadvantages include setting in the comb, possible poor flavour perception, lower yields with modern hybrid varieties and the need to process immediately the honey is ripe.

The perceived downside to OSR cropping usually relates to the rapid onset of crystallisation of the capped honey due to the high glucose content of the nectar. In order to overcome this problem Lynne outlined her strategy.

Lynne’s management strategy

If you intend to take advantage of OSR for honey production the colonies will need to be large and vigorous, so late winter/early spring feeding with 50:50 sugar syrup to stimulate egg laying will be required. Contact feeders are best. Pollen patties may also be needed to supply the extra protein for the brood production.

• Prepare your site and time the move so that there is plenty of nectar available straight away.
• During the flow, regular inspections will be needed to prevent possible swarming.
• Ensure ample supering as it takes around 3x more space to process nectar as the ultimate volume of ripe honey.
• Remove and process capped honey as it ripens. Immediate processing will minimise crystallisation.
• Make sure you know when spraying will take place.
• After the flow you will have large colonies with most of the stores removed, so ensure there is adequate space in the hives for the large colonies and feed if necessary.

Extraction

Lynne recommended extracting any liquid honey and then scraping back partially set honey to the midrib to recover as much as possible. Any residue can be sprayed with water and replaced on the hive. Fully set honey has to be cut out of the frames, packed into tubs and warmed at 55°C for 12 hours. The wax rises up as a mush and eventually separates from the melted honey. Allow to cool to 30°C before pouring the honey off.

Honey processing

The procedure for bottling tubs of set OSR honey is to warm the set material until it is ‘porridgey’ at around 32°C, stir until smooth, allow to settle, then bottle and store at 14°C to optimise setting. If full filtering has not been achieved before putting in bulk tubs, the honey will have to be warmed sufficiently to flow through the filter. With partially crystallised honey this can be troublesome.

To prepare soft set / creamed honey with a 10% ‘seed’ of OSR honey, first warm your floral honey until liquid (up to 50°C) and cool to 30°C. Warm the ‘seed’ honey until ‘porridgey’ (c32°C) then combine the two portions with stirring, avoiding the introduction of air. Allow to settle, then bottle and store at 14°C. Recommended long term storage temperature is 10°C.

Question & Answer session

During the Question & Answer session the notable topic was temper of the bees during and after the OSR was in flower. Lynne explained this could be caused by removal of stores causing defensive behaviour. Any situation where there are unemployed and overcrowded foragers will tend to cause problems. There is also a “starvation” scenario which can arise from dietary insufficiency as well as lack of quantity for a very full nest, possibly the effect of erucic acid. Lynne stated she has not had too much bad temper as there are usually other high-yielding sources coming on, notably field beans.

Self-sufficiency and Apicentric Beekeeping

Talk by Wally Shaw to a joint meeting of East Devon and West Dorset Beekeepers, 14th January 2020

Where did it all go wrong for honey bees?

Apis mellifera was introduced all over the world in 19th century, including Asia, where it met with Apis cerana and its long-established parasite, Varroa jacobsonii mites. The parasite jumped species and, at some point, became a genetically distinct species, Varroa destructor. This new mite entered the UK in 1992 and the rest is history.

What do we do about it?

Importing bees is not the answer with the attendant risks of importing exotic pests as well (Tropilaelaps, Small Hive beetle etc), plus the very real risk of disease organisms being imported with the bees. The Welsh Beekeepers Association (WBKA) have pledged to minimise imports and make Wales self-sufficient for bees. The WBKA’s pragmatic solution is to enable all beekeepers to make increase/raise queens for themselves. Wally believes this is not as difficult as it is often made to sound.

How queen rearing is taught in Anglesey.

The WBKA publication ‘Simple Methods of Making Increase’, written by Wally and available on the WBKA website, is a good starting point. The simple, small-scale methods are arguably better for the bees and help to retain genetic diversity.
In their first year, ‘Beginners’ are provided with a starter colony, a 5-frame nuc of locally adapted bees. In their second year the ‘Improvers’ are taught to make their second colony for themselves, thereby acquiring a skill for life.

Locally adapted bees have been shown to be better adapted to our highly variable climate, need less management and on average produce higher yields (see COLOSS experiments). Local adaptation will only occur with minimal importation of ‘different’ strains of bee. They will be genetically stable and will be similar in beekeeper’s hives and local feral colonies. Two-way traffic between hives and feral colonies is desirable.

Anglesey bees and Apicentric beekeeping

The characteristics of Wally’s local bees are almost pure Apis mellifera mellifera. They are black without prominent stripes, thrifty with reduced brood rearing in poor conditions, they never exceed their resources and they hoard pollen.
Apicentric means the needs of the bees should be considered first, based on the biology and ecology of honeybees. This is not the same as natural beekeeping.

We need to understand bees

The apparent ‘intelligence’ of bees is a series of hard-wired programmes initiated by various stimulae or prompts, so bees can be conned into doing what we want e.g. with pre-emptive swarm control, but can be confused by, say, an artificial swarm using the Pagden method. Apicentric beekeeping allows the colony to choose the new queen for themselves.

Apicentric guidelines for making nucs

1. Nucs should be populated with bees from the same colony that raised the queen cells.
2. Each nuc given 2 or more queen cells on the frames on which they were raised.
3. Queen cells harvested as soon as possible after sealing (day 8 or 9).
4. The Nuc entrance should be blocked while being populated.
5. Completed nucs IMMEDIATELY removed to remote mating apiary.

The reasons why this seems to work are:

• It is more NATURAL. The new queens are raised by their own sisters.
• Supplying multiple queen cells allows bees to exercise their choice.
• Blocking the entrance and moving immediately to another apiary prevents loss of flying bees which ensures good age balance in the nuc.
• Using newly sealed cells means there will be a minimum of 9 days to mating. The bees have time to familiarise with their new surroundings.

Selection criteria for breeder colonies

• Performance of queen should be known e.g. a queen in her 3rd year.
• Only make a small number of new colonies from any one queen. This helps to maintain genetic diversity.
• The breeder queen’s colony should be healthy, a good honey cropper, not too prolific, of a reasonable temperament, and not too swarmy.

Varroa resistance

The second part of Wally’s talk focussed on ways in which bees might acquire Varroa resistance or tolerance.

Over the last 25-30 years breeding strategies have been looking at traits such as grooming, hygienic behaviour, Varroa sensitive hygiene (VSH) and shorter capping periods, with very limited success. When introduced into an open-mating situation the ‘improvements’ are often dissipated.

It has been assumed that natural selection would solve the problem given time, but any Varroa treatment will prevent or seriously slow down natural selection.

There are instances of colonies left untreated in honey production apiaries becoming resistant to mites and able to keep the mite population in check and still produce a good homey crop.

A completely new behavioural mechanism has been found – bees uncap and re-cap brood.

How is this done?

Recent studies have revealed the main mechanism.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5955925/
A completely new behavioural mechanism has been found to be responsible. Bees uncap and re-cap brood.

The behavioural sequence is:

• First bees investigate sealed brood cells by examining cappings with tongue and antennae.
• Cells perceived to have a problem are uncapped with the mandibles, removing cappings and pupal skin.
• Most cells later re-capped.
• Some cells may be uncapped more than once.
• Other cells may be left uncapped or partially re-capped.
• A few cells may have brood removed and discarded (VSH).

It seems this behaviour reduces the number of viable daughter mites that finally emerge, but the uncapping and re-capping does not affect the emerging brood. Mostly, only brood cells in which Varroa has bred are uncapped, which implies bees can detect breeding mites. Whatever the mechanism, uncapping affects the mites but not the pupa and appears to be a result of natural selection.

Uncapping behaviour can be observed in ALL colonies so far investigated, so has probably arisen through natural selection acting on an inbuilt trait which is universal in Apis mellifera.

Wally’s parting remarks were:
For natural selection to work, we need to move towards non-treatment!

Strangely, uncapping behaviour does NOT appear to apply to drone brood. More work needed to clarify such issues.