Bee Diseases

A talk by Robin Hall, Regional Bee Inspector, Gloucestershire

Date: Thursday 4 April 2000

Venue: Church Rooms, Stow on the Wold

Robin explained how he and Dave Maslan are the two inspectors who cover the North Cotswold area.

The Cleanliness of Equipment

· Soak bee suits in soda to remove propolis

· Use disposable gloves. Washing up gloves (“Marigolds”) with surgical disposables over the top is the best combination. Wash the gloves thoroughly in disinfectant after use

· Scrub smoker clean regularly with soda

· Useful tip – add lavender and/or rosemary leaves to smoker fuel to help calm bees

There are three diseases which are statutorily regulated

1. Varroa

Varroa was first identified in the Far East and then in India. It was carried into Europe on the Indian Honey Bee which was taken for research to Germany by scientists. Now it has spread throughout Europe.

It was first found in England in 1994, probably crossing the channel in swarms carried in boat containers. It thus infected the local population, initially in port town such as Felixstowe and Dover. At about the same time the mite was found in Devon. It has now reached Scotland.

Nationally the impact of varroa has resulted in

· A 50% decline in the number of beekeepers

· Up to 85% decline in the number of bee colonies in some areas

The other two statutorily regulated diseases are the Foul broods (American and European). Both were known to the ancient Greeks and Romans and are named because of the horrible smell they cause.

2. American Foul Brood (Paenibacillus Larvae)

This is a spore-forming bacteria which has a very hard coat and can live for more than 50 years. The bacteria germinate in the gut of the bee. They break through the gut wall and infect the bee blood and the bee larvae dies of septicaemia.

As the bee breaks down, it leaves a scale with contains several million highly infectious spores.

The signs of American Foul Brood include

Ø Pepperpot brood pattern

Ø Sunken cappings

Ø Irregular holes (small) in the centre of the brood where bees chewed into the cap

Ø Greasy comb

The test for this disease involves the insertion of a matchstick into the comb. The stick will withdraw with up to 1 ½ inches of glutinous stringy material attached to it.

There is no effective treatment to cure this disease and if it is suspected, contact Robin Hall immediately.

Unfortunately if a beekeeper has this disease all bees, frames and zinc Queen excluders must be burnt. The hive and any other sort of Queen excluder must be sterilised and flamed. The remaining hives in the apiary will be inspected 6 weeks later.

American Foul Brood is rare and there is no apparent logic to its’ distribution. However its possible spread may be due to the purchase of second hand equipment, feral colonies or collected swarms

3. European Foul brood (Melissacocus plutonius)

Also known as “The Disappearing Disease” / “The Ghost Disease”

This is a pure bacteria which needs a host. The larvae are fed contaminated food by nurse bees. The bacteria enters into the stomach of the larvae and proliferates. The bee larvae compete with the bacteria who digest the food and the larvae dies.

This is a disease of the uncapped brood. The larvae die before capping occurs.

The signs of European Foul Brood include

Ø Pepperpot brood capping

Ø No longer C-shaped glistening pearly white healthy larvae. The larvae become discoloured twisted and have a “melted down” appearance. Eventually the larvae turns dark brown /black

Ø No smell but secondary infections can give a “rotten fish” smell

It is known as the disappearing or ghost disease because the bees clear out the larvae and so sometimes you don’t know that you have it. The best time to find EFB is in the Spring/or is when a good honey flow is on. The bees appear to neglect the brood, the EFB bacteria compete for food in the gut of the larvae which then dies.

In severe cases of EFB the bees, frames are burnt and all hive parts are sterilised by scorching. In moderate to small infection the bees are treated using antibiotic or the beekeeper may elect ‘the shook swarm treatment’ This requires the beekeeper to provide a clean hive with frames fitted with foundation. The bees from the infected hive are then shaken into the ‘new’ hive, and fed with antibiotic and sugar syrup The old infected frames are then burnt. A follow up inspection is made eight weeks later in the case of treatments In the case of destructions the inspection is made six weeks after.

Diseases associated with Varroa

1. Deformed Bee Wing Virus

The varroa mite is the vector for this disease which results in ragged, stumpy wings on the bees

2. Sac Brood Virus

The varroa mite is associated with this virus. The larvae fill with fluid and die.

Also beware!

· Wax Moth

· Wasps