Part 5 ‘Pests and diseases’

Part 5 ‘Pests and diseases’

Verroa mite

There are a number of pests and diseases that have harmed bee colonies in the UK.   Here are some of the most common honey bee pests and diseases that can harm or adversely affect your hive.

Varroa destructor or Varroa mites - These are the most common pests in the UK that are known to infect honey bee colonies.   These external parasitic mites attach themselves to the body of honey bees.   Once attached, the varroa mite sucks Hemolymph out of the honey bee.   Hemolymph is the blood of honey bees and consequently, varroa mites will weaken your bees and spread viral ' varroosis' diseases throughout your hive; which in turn can result in the death of your bee colony.   Varroa mites reproduce on a 10 day cycle wherein they enter the brood cell of a hive and lay eggs on the honey bee larvae.  Once the honey bees develop, the mites attach themselves to the bees. As these bees spread throughout the hive the mites can then begin to feed off of other bees and larvae.

Subsequently, it is important to regularly check your hive for varroa mites.   It is worthwhile scrutinising your hive's drone bees as varroa mites are known to primarily target drone bee cells.   Once you have identified a varroa mite infestation there are several treatment methods that you can utilise.   There are several 'miticide' chemicals on the market which you can buy from your local beekeeping supplier in order to treat your colony.   Always read the instructions on the miticide label carefully.   Moreover, varroa mites can develop resistance to miticides so it is advisable to alternate the products which you use each season.   Common synthetic miticides include;

Apistan: These strips contain pyrethroid insecticide which you can hang in the brood chamber of your hive.   Your bees will brush against these strips and spread the miticide throughout the hive; thus effectively killing any varroa mites.

Check-mite: These strips contain organophosphate insecticide and they offer an alternative to Apistan.   Check-mite is useful if your particular varroa mite infestation has developed immunity to Apistan.

As well as synthetic miticides, there are several naturally occurring chemicals that you can use to treat a varroa mite infestation.   Some of the most effective naturally occurring chemicals include;

Mite-away: These pads or vapour spray products contain formic acid which eradicates any varroa mites in your hive.

Powders: You can use powdered sugar, talcum powder or other powders with a grain size of between 5 and 15 µm. Sprinkle these powders on your bees to prevent varroa mites from feeding on your bee's hemolymph

Hopguard: These strips are made from natural hop compounds and serve as a natural alternative to Apistan.

Oils: Essential oils such as lemon, mint, and thyme oil, as well as mineral oils, can be inserted into your hive to protect your bees from varroa mites.

As well as natural and synthetic chemicals you can also use a drone comb to capture and remove varroa mites from your bee hive.   You can purchase a drone comb online or from your local beekeeping supplier.   This special drone comb foundation frame has large hexagons imprinted in the sheet.   As a result, your bees will only construct a drone comb on these specific sheets. Given that varroa mites prefer to attach themselves to drone bees, they will be attracted to these sheets.   Once the drone cells are caped you can remove the foundation frame and place it in the freezer overnight to kill off the varroa mites from the cells.   You can then return this sheet to your hive and repeat the process until all varroa mites are eradicated.

Small Hive Beetles or Aethina tumida are extremely destructive pests for honey bee colonies. They are reddish or dark brown in colour and can cause damage to the comb, stored honey and pollen within the hive. This due to the fact that small hive beetle larvae will travel throughout honeycombs; feeding, defecating, and causing the honey to ferment and discolour as they travel throughout the combs. Moreover, if your hive has been contaminated by a heavy small hive beetle infestation it may cause your bees to abandon their hive.

If you regularly check your hive for small hive beetles and larvae you can actively prevent a large scale infestation from occurring.   Once you have detected small hive beetles within your hive, there are several measures that you can put into place.   As well as using the miticides mentioned above for treating varroa mites, there are a variety of traps which you can purchase online or from your local beekeeping supplier in order to remove small hive beetles from your hive. Amongst some of the most popular beetle traps include;

Wasp Traps: These traps can be placed on the bottom board of your hive.   They contain a shallow pool of oil which is covered by a slatted screen to exclude your honey bees from becoming trapped.   Adult small hive beetles enter the trap from above, fall into the oil and drown.   However, in order for these traps to be effective, they must be kept level at all times.

Hood Traps: These traps attach to a standard beehive frame and contain a compartment that is filled with apple cider vinegar.    This vinegar attracts the beetles who fall into compartments which are filled with mineral oil and they then drown.

Freeman Beetle Traps: Similar to the bottom boards in Wast Traps, Freeman Beetle Traps contain a 3 mm screen mesh and an oil-filled tray which is inserted into a compartment below the screen mesh.   The adult beetles enter the trap to escape from the bees, fall into the oil and subsequently drown. Beetle larvae can also fall into the trap as well as other pests such as varroa mites.   However, much like Western Traps, Freeman Beetle Traps must be kept level in order to function effectively.

Beetle Jail Traps: These traps are designed to prevent hive beetles from invading a beehive in the first place. They trap the beetles as they seek to enter the hive and drown them in oil.

European Foulbrood or Melissococcus plutonius is a bacterium which affects the gut of honey bees that have eaten contaminated food.   Symptoms include dead or dying larvae which appear curled upwards and which have turned a brown or yellowish colour.   Your bees may also appear melted or deflated with dried out, rubbery, or apparent tracheal tubes.   European Foulbrood is considered as a stress disease which affects unhealthy bee colonies.   Therefore if you ensure your bee colony is strong and healthy then they are far less susceptible to contract European Foulbrood.   If you suspect your bees are suffering from European Foulbrood then you should contact your local Beekeeping Association immediately for treatment advice.   Your colony can be treated by antibiotic medications such as oxytetracycline or via a Shook Swarm husbandry method. To perform this method you will need;

  • A fresh brood chamber
  • A floor with an entrance block
  • A full set of frames and foundation
  • A spare queen excluder
  • An inner cover
  • A hive top feeder
  • A sugar syrup feed
  • A container for the combs

Before carrying out this method you will need to ensure that all of your equipment is sterilised and that you are wearing protective clothing. Listed below is a step-by-step guide on how to carry out the Shook Swarm husbandry method;

  1. Shift your hive so that it can be shaken to one side.
  2. Place the clean floor with entrance block on the original stand
  3. Place your spare queen excluder on the floor.
  4. Place your fresh brood chamber with frames and foundation on top of the queen excluder
  5. Remove a few of the frames from the centre of the brood chamber to create a small, dark space into which you can insert your bees.
  6. Dismantle your original hive and place your queen bee in between the frames and foundation.
  7. Remove each brood frame and shake the frame diagonally across your new brood chamber.
  8. Place the old, empty frames into the container. If these frames are infected with European Foulbrood then they must be burned to remove all traces of the disease.
  9. Repeat this process with all of your remaining frames.
  10. Insert the spare frames into the central space of the new brood chamber
  11. Insert your queen into the new brood chamber.

Colony Collapse Disorder is a phenomenon in which worker bees from a European honey bee colony disappear for no apparent reason. Although the causes for colony collapse disorder remain unclear, many researchers have cited possible causes which include: varroa mites, the use of pesticides, harmful pathogens, and genetic factors, loss of habitat, malnutrition, and changing beekeeping practices. Initial symptoms of colony collapse disorder include:;

  • An insufficient workforce who are unable to maintain the current brood
  • A workforce consisting primarily of young adult bees
  • The colony are reluctant to consume the provided food stores

Once colony collapse disorder has taken place you may notice the following signs;

  • Brood which have been capped over in their cells
  • Substantial food stores of honey and pollen which are not immediately robbed by other bees or pests
  • The presence of the queen: If the queen has disappeared the hive is considered to have died because it is queen-less. However, if the queen is present when the hive dies then it is considered colony collapse disorder.

Although the primary cause of colony collapse disorder is as yet unknown, there are several measures you can put into place to prevent it from adversely affecting your hive.   As well as these measures, you can contact your local Beekeeping Association for more information and advice;

  • Feed your colony Fumagillin in the spring and autumn to prevent Nosema; a fungus that adversely affects honey bees. It has been suggested that Nosema can create stress symptoms amongst bees which can lead to colony collapse disorder.
  • Replace your hive's old combs with new foundation every year in order to reduce the amount of residual chemicals in the older beeswax.
  • Provide adequate ventilation for your hive.
  • Perform regular checks on your hive for pest infestations or diseases.
  • Feed your bees when their natural food stores of nectar and pollen are depleted.
  • If your hive displays symptoms of colony collapse disorder, replace all of your equipment and do not use it again on that particular hive.

Do not use synthetic chemicals or pesticides in your garden which may be harmful for your colony.

Link to part 6