Pests and diseases

The most common pests in Devon seem to be:

• Wasps in the late summer/autumn. these can effectively destroy a colony by robbing honey from the combs. Restrict the hive entrance to make it easier to defend. Some beekeepers swear by wasp traps placed strategically near the hive.
• Mice - will enter the hive late in the season, looking for a free meal and dry accommodation. Fix mouse guards on the entrance (usually a metal strip with 9mm holes drilled in it shown left).
• Woodpeckers - not found in all areas, but a capable of considerable damage where they do appear. Various advice is given, from covering the hives with chicken wire mesh to attaching strips of fertilizer bags (which flap gently in the breeze).
• Greater and Lesser Wax Moths - Most commonly seen as tunnelling in a line beneath the surface of the comb (shown right.
• Varroa mites - (see more information further down the page)  

Bee Diseases

Notifiable Diseases and Pests of Bees in England (defra)

• American foul brood (AFB) (Paenibacillus larvae var. larvae) is a bacterial disease of honey bees. Affects only the sealed brood. Symptoms include 'pepperpot' comb (random empty cells), an upleasant smell (decaying larvae), sunken and discoloured cappings. Scales of dried bacteria are usually visible. Diagnosis is made using the 'rope' test (shown right) and the Regional Bee Inspector will do an LFD testing kit. All colonies found infected with American foul brood are compulsorily destroyed and affected apiaries are placed under the conditions of a Standstill Notice prohibiting movement of bees or equipment.
• European foul brood (EFB) (Melissococcus plutonius) is a bacterial disease of honey bees. Mainly affects the unsealed brood. Infected larvae move within the cells and assume a twisted unnatural appearance in death. Bees usually attempt to remove infected larvae from the hive. Dead larvae can appear 'melted' and yellowish-brown. Diseased apiaries are placed under the conditions of a Standstill Notice prohibiting movement of bees or equipment. Diagnosis will be made by the Regional Bee Inspector using an LFD testing kit. Lightly infected colonies are treated with an antibiotic by an authorised bee inspector, although the shook swarm technique without antibiotic is increasingly being applied. Colonies that are considered to be too weak or too heavily infected are destroyed.
• Small hive beetle (SHB) (Aethina tumida) commonly known as SHB, is an exotic pest of European honey bees. The beetle is indigenous to Africa where it is considered a minor pest of honey bees, and until recently thought restricted to that continent. However, in 1998 it was discovered in the USA, where its occurrence is now widespread, and in 2002, the beetle was also found in Australia and Canada. The beetle is exotic to the European Community, but is a serious threat to the sustainability of European apiculture. The beetle is 5-7mm and black with clubbed antenae and tends to hide from the light. Larvae not to be confused with Wax Moth which has legs all along its body like a caterpillar.
• Tropilaelaps (Tropilaelaps spp) are potential new threats to European beekeeping. There are known to be at least two species of the mites, Tropilaelaps clareae and Tropilaelaps koenigerum. They are native to Asia and have spread from their original host, the giant honey bee, Apis dorsata, to the European honey bee, Apis mellifera. The mites are exotic to the European Community but are notifiable throughout. These parasites are about 1.8 x .06mm. Their life-cycle and treatment are similar to the Varroa mites.

If you suspect any of these diseases:

• Re-assemble the hive and reduce the entrance to minimise robbing
• Do not inspect other colonies
• Contact the Regional Bee Inspector (SW) Adam Vevers
    phone: 01364 653474
    email: adam.vevers@fera.gsi.gov.uk
• Disinfect your hive tool and smoker
• Wash your bee suit.

Other Pests and Diseases

Other diseases and pests of bees:

• Varroa - first discovered in UK in 1992, this external parasitic mite (Varroa destructor) has caused huge bee losses. It reproduces in the sealed brood cells and feeds on the bees by sucking the haemolymph (blood) from them. Latest variants are pyrethroid resistant. Left untreated, Varroa will destroy a colony. It has been linked to Colony Collapse Disorder (CCD) and can be a vector for viruses (including Deformed Wing Virus). Adult Varroa are 1-1.8 x 1.5-2mm. Infested bees may live shorter lives, fail to thrive, have shrunken and deformed wings and reduced natural resistance to infections. Control by applying Integrated Pest Management (IPM) - a number of concurrent strategies, such as dusting with icing sugar (promotes cleaning behaviour), applying Apiguard™/thymol, Oxalic Acid during winter and open mesh flooring. Mites should be monitored using a tray underneath the hive.
    Video of Varroa - Life Cycle: click here
    Treatment of Honeybees with Oxalic Acid: click here
    Link to Varroa calculator on BeeBase: click here
• Nosema - Could be one of two similar infections (Nosema apis & Nosema cerana), the latter being common to Devon. Diagnosis is with a microscope. Symptoms include untypical faeces at the entrance of the hive (see left). Bees crawl/lose the ability to fly, have 'K' shaped wings and have a greasy abdomen. Can be treated in some cases with Fumidil B in the Autumn. Replace contaminated combs and avoid excessive manipulations.
• Chalkbrood fungus (Ascophaera apis) Infected larvae are killed after being capped. Adult bees remove the mummies. Best control is maintaining strong colonies which show hygienic behaviour.
• Sacbrood (virus) - known as 'Chinese Slipper' due to the shrivelled appearance of larvae. They are usually uncapped by adult bees. There is no specific treatment and it is rarely serious. Requeen if the colony is badly affected.
• Acarine (Tracheal) mites (Acarapis woodi), also known as 'Isle of Wight Disease'. Responsible for nearly wiping out the native British bee in the last century. Diagnosis by microscope. Menthol has been used to treat, as have grease patties.
• Chronic Paralysis Virus - affects adult bees, especially if are active but crowded for long periods (as in a wet summer). Symptomised by inability to fly/trembling/crawling in grass with bloated abdomens, shiny greasy bodies and no hair. Best cure is requeening.

Further reading:

• Diseases of the Honeybee - Wikipedia
• Bee Pests and Diseases - BeeBase
• Bee Health Programme - Defra
• Bee Diseases, Parasites and Afflictions - Dave Cushman
• Bee Diseases - British Beekeepers Association
• MAAREC Diseases & Pests / Colony Collapse Disorder