Diseases of bees / Ministry of Agriculture and Fisheries.

Date:
1948
Catalogue details

Licence: Public Domain Mark

Credit: Diseases of bees / Ministry of Agriculture and Fisheries. Source: Wellcome Collection.

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    is most convenient to consider the various forms of paralysis separately. It should, however, be clearly understood that other diseases of the honeybee, such as nosema, amoeba and acarine disease also result in some of the symptoms ascribed to paralysis. The following classification of the various types of paralysis is somewhat tentative and several of the types described are very difficult to distinguish from one another, even when a complete history of the case is available. Some of the forms of Bee Paralysis are very common and widespread in this country and cause serious losses to bee-keepers. (1) Infectious Type. Sicns. Trembling of the body and wings, and often sprawled legs and wings. Often most of the bees concerned become hairless, and have dark and greasy looking abdomens. In the early stages of this disease the bees collect at the entrance of the hive and show evident restless- ness, the diseased individuals appearing lethargic and putting up no defence when pulled about by their more active sisters. Cause. This form of paralysis is almost certainly a definite disease and can be transmitted from an infected to a healthy bee. The trouble can spread from one colony to another by the drifting of infected individuals. Unfortun- ately this disease can readily be confused with Type (3) (below) and, apart from experimental inoculation of healthy bees with the blood from diseased individuals, no method of separation is known. TREATMENT. No satisfactory method of treatment is known and, if the trouble does not disappear after a few weeks it is probably wisest to destroy the colony concerned and so prevent further spread of the disease in the aplary. (2) Genetical Type. SIGNS. Similar to those described for Type (z). In addition bees are found emerging from cells quite hairless. Cases with mal- formed wings are known. Cause. A hereditary fault in the queen. TREATMENT. Requeening with a young, healthy, unrelated queen may be expected to effect a complete cure in all cases of this type of paralysis. (3) Nitrogen Deficiency Type. Sicns. Similar to those described for Type (2). Cause. Anything which upsets the nitrogen metabolism of worker bees. The complaint is not a true disease, in the sense that it is neither infectious nor contagious, and in this country appears most frequently in the early part of the season, but it may break out at any time. It appears to be caused either by prolonged lack of pollen in the hive after brood rearing has become well advanced or, to what is really the same thing, excessive brood rearing continuing during a dearth of natural pollen. The external skeleton of afflicted bees becomes brittle, so that the individuals concerned lose their hair which easily breaks off, and they may even lose their wings in this way. TREATMENT. The obvious treatment is to supply the colony concerned with one or more combs of pollen, and it has also been found to be beneficial to give the affected colony one or two combs of emerging brood. It might also be worth while to feed soya bean flour made into a stiff paste with sugar