Wasps (Yellow Jackets)   

It is at this time of year (Autumn) that the Wasp becomes a serious nuisance to the beekeeper.  Their own source of food is scarce and they will do their utmost to rob honey from beehives. The following tips may therefore be of assistance in order to prevent this happening: 

Do ensure therefore that entrances are closed down to a bee space, as this will assist the colony to keep out unwelcome visitors.    
Check clearer boards, making sure that feeder holes are blocked off.
Examine all boxes, supers and brood chambers and seal off any cracks which may be present. The wasp only needs a small hole to gain access and once it has found a way in, it will return with many more. Once robbing starts, it is virtually impossible to stop. It has happened to me previously, so don't let it happen to you.
Place traps in and around the apiary in order to reduce wasp numbers. The old fashioned method of a jam jar containing water and jam is still very effective. Wasps climb in through the small hole in the lid and then drown in the water.