Visit by Phil Spillane, Seasonal Bee Inspector for Oxfordshire to the V&DBKA Association Apiary on 26 May 2012 by Jane Greenhalgh
Phil started the meeting by introducing himself and what he does. He is our point of contact if we should discover any signs of disease with our bee colonies, and he encouraged all members to register on Beebase, and all new beekeepers to request an inspection during their first year of beekeeping.
He inspected two hives during the course of the meeting, starting with a hive that was a colony from last year. When last looked at, it had 8 frames of brood, a queen cell and evidence of chalk brood. Phil commented that it had been a disappointingly bad year so far for chalk brood, a fungal disease, and this was probably due to the cold and damp conditions in April, where hives were getting cold at their extremities. However, there was no sign of chalk brood in the hive and he believed the warm sunny weather of the last couple of weeks was helping it to clear up across the region. He agreed that up until now it had been an exceedingly strange year for beekeepers and bees alike, but everything appeared to be settling down and the bees were busy filling supers, sometimes as quickly as in two days.
Interestingly when dismantling the hive, Phil laid the super right in front of the entrance (something I have always personally avoided!) He felt that this encouraged the foraging bees to make straight for the super, and not for him. It is only the mature bees in a hive that sting!
There are a number of things that you are looking out for in an inspection, from the point of view of looking for disease and pests. Small hive beetle is a major problem in America and Australia. It is not here yet, but beekeepers need to be alert for it to try and prevent its spread. It causes fermentation in the honey and the bees leave. The two bacterial diseases, European Foul Brood (EFB) and American Foul Brood (AFB) are mercifully rare in our area, but again, we need to be alert and know what we are looking out for. If you suspect disease, you should ask for a visit from the Seasonal Bee Inspector. (Details at the end of this report). Normal healthy capped brood should have an even, biscuity coloured capping. Learn what it looks like, and then you will be ready to spot when something is amiss, and whether or not it is serious.
When inspecting a brood frame for disease, it is important to be able to see the brood, so give the frame a sharp shake downwards to dislodge as many surface bees as possible. Look at the uncapped larvae. If they are healthy, they should be curled neatly in the cells, a pearly white colour and their segments clearly visible. If they are melted-looking, or discoloured then it is cause for concern and further investigation is needed.
Our main enemy in this region at this time is the ubiquitous varroa. There are several ways to check for varroa in your colony. A common symptom of varroa in hives is bees with deformed wings, caused by the Deformed Wing Virus which the mites carry. This will eventually cause the colony to weaken and die out. There was no evidence of this in the hives he inspected.
A second method is to check your drone brood. Using the life-cycle of the varroa mite, which prefers to breed in drone brood, you can uncap several drone cells. The varroa mite if present is clearly visible as a chestnut spot on the white larva. Because of the extra size of drone brood, and the three extra days it takes them to hatch, varroa are able to produce an extra baby in each cell giving you three mites per cell. The blind varroa mites hitch a ride on nurse bees, smell out uncapped drone brood, enter the cell and hide under the larva, until the larva is sealed, whereupon it lays its young. Numbers of varroa in a hive can therefore rapidly increase in a hive during the season. If you uncap 100 drone cells, and find that more than 10% have mites in them, then you have a problem.
One of the best ways to ascertain the level of infestation you have is to count the number of mites visible on your varroa floor during your weekly inspection. It is really important to clean your varroa floor at each check, so that you can see what has arrived during one week. If it is difficult to spot them or count them, one other method is to scrape all of the contents of your varroa floor into a jar of methylated spirits, and the varroa will float to the top, making them easier to count. This will only give you a rough idea of what your problem is, because between 60 -80% of your mite population will be in the brood. At what stage do you need to worry? Check the quick reference at the end of the report!
Since its introduction into this country in 1992, varroa has spread rapidly, and is readily able to develop resistance to chemical control methods. Our best defence against it is to manage it, rather than seek to eradicate it. There are several ways in which management can be achieved, and a combination of a number of these is probably our best hope. This is known as Integrated Pest Management.
Phil prefers not to use chemicals, because of the resistance problem. He prefers the drone cull method: Around the beginning of June, remove the dummy board and put in a super frame into the brood box. After three weeks, the space below the super should be full of drone brood. Then remove the super and remove and burn the drone brood. The top half may well be full of honey, and you can chose to extract this, or even use thin unwired foundation to make cut comb honey. In mid-season the bees are not contributing to the honey flow, as the hatched bees there are too young to forage, and will have died before becoming winter bees. Losing a frame of brood at this stage should not hurt the colony too badly. Then, once the honey has been removed in September, the bees should be treated with a thymol based treatment, such as Apiguard.
Many of the members present disagreed with this approach, saying that they had tried it in the past, but culling the drones had resulted in poorly mated queens, leading to weak colonies, or even drone-laying queens. Plus, removing the dummy board and having another frame in place increased the risk of rolling the queen and losing her. Plenty of lively discussion ensued!
Another approach is to use hive clean when the honey is not flowing, use Apiguard in the autumn, and treat with oxalic acid over the winter months. Oxalic acid will kill brood so it should ONLY be used in the winter months, or on a swarm. In a warm winter, this might be problematic, because brood can be present throughout the winter. (As an aside, he mentioned how to spot chilled brood – it looks like mouse droppings. This is where the flying bees have been unable to keep the brood warm for some reason and they die and mummify.)
Whatever approach is used, it is our responsibility as beekeepers to take an active approach to varroa management to keep our hives healthy. Frames should be changed regularly – at least every three years – to reduce any lurking diseases, and good hygiene should be maintained at all times, cleaning gloves and tools between inspections of different hives, so as not to spread disease. Plastic gloves are preferable to leather for this reason. One method of frame swapping is a modification of the Bailey method – put a brood box full of new frames on top of the existing brood box, separated by a queen excluder (like a super-sized super). Let the bees fill this with honey, then extract. Then replace the upper brood box, with the drawn out frames, without a queen excluder. The bees should rapidly go up to clean up, encouraging the queen to lay up top. Let the queen lay up top, make sure she is in the top box, then put a queen excluder between the brood boxes, and on top of the top one, and any hatching bees in the lower box will go upwards onto nice new frames. Once all the lower brood bees have hatched, remove the lower brood box, melt down the wax, destroy the old frames and sterilize the box. Opinion varies (as always!) as to how effective this is, but this method does not come at the expense of your honey, and may help delay swarming. Pick your time of year!
The second hive examined had double brood boxes as it was to be used for making up nucs. These ideally should be made up of three frames with queen cells. Making up nucs with just brood is likely to result in emergency cells and scrub queens. The quality of the queen depends on how well she was fed from the start. Only leave one good queen cell in each nuc. A hatched queen can take up to a month to start laying (longer, in cool weather, as many of us have found this year) and they do seem to start laying quicker if kept in a small nuc rather than a brood box.
Much excitement ensued when the top brood box was examined and we found not one but two virgin queens on the same frame. The bottom box appeared to be queenless so they were both put in the bottom brood box with a queen excluder on top and left to fight it out!
A most interesting and informative day was had by all, and our grateful thanks to Phil Spillane for sharing his enthusiasm and knowledge with us.
Should you need to contact Phil, he can be reached at:
Home: 01865 396383
Mobile: 07775 119470
email: Philip.spillane@fera.gsi.gov.uk
The rough guide to Daily Mite Drop: (Count the number of mites on your varroa board at your weekly inspection and divide by 7 to get the average daily drop)
Winter/Spring= 0.5 mites, May= 6 mites, June= 10 mites, July= 16 mites, August= 33 mites, September= 20 mites. Anything above these levels, action
needed!
