DIAGNOSING BEE DISEASES IN THE APIARY 27 



with soil water from about the hives may become infected. This is 

 probably the most common way by which the disease spreads. The 

 bacteria seem to enter the blood of bees by way of the breathing 

 tubes. The presence of large numbers of bacteria in the food seems 

 not to injure bees; but if a drop of water that contains the bacteria 

 is spread over the entrance to the breathing organs (spiracles), dis- 

 ease and death from septicemia usually result. The disease does not 

 spread readily unless plenty of moisture is present. The bacteria are 

 soon killed by drying, «,nd the disease rarely occurs under dry condi- 

 tions. Several other species of bacteria and yeasts cause septicemia 

 when they are placed in the blood of bees by puncturing the body 

 covering, but they seem to be unable to gain entrance to the blood of 

 uninjured bees. 



SYMPTOMS 



Bees die within a few hours after they have shown the first symp- 

 toms of septicemia. Sick bees leave the hive or are carried out by 

 healthy workers. Sick bees resemble bees that are chilled, and their 

 movements gradually become slower. Before death, the blood loses 

 the normal clear, pale-brown color and becomes turbid and milky, 

 owing to the presence of many bacteria. This symptom can some- 

 times be used in diagnosis in the apiary. By pulling off the head 

 and abdomen of a dying or recently dead bee and pinching the thorax 

 between the fingers, one can obtain a drop of blood for examination. 

 Dead bees decay rapidly, the muscles of the thorax soon becoming soft 

 and pasty, and the bodies have a characteristic putrid odor that is of 

 some assistance in the diagnosis of this disease. Within 1 or 2 days 

 the body, legs, wings, and antennae usually fall apart at the joints 

 when the bees are handled. 



EFFECT UPON THE COLONY 



Only rarely are colonies noticeably weakened by septicemia, but 

 many individual bees may be killed. Septicemia is less serious than 

 Nosema disease or acarine disease. 



Amoeba Disease 



cause 



Amoeba disease of bees, caused by a one-celled animal parasite, 

 Vahlkampfa (M alpighamoeba) mettiflca, was discovered a few years 

 ago in Europe. This parasite grows in the excretory organs of 

 adult bees. In 1927 it was found in two colonies of bees in the 

 apiary of the Bee Culture Laboratory at Somerset, Md. In 1929 

 it was recognized in a sample of bees sent to this laboratory from 

 California, and in 1935 in a sample from Illinois. In Europe, amoeba 

 disease was found only in colonies with Nosema disease, and it was 

 suspected that the two diseases were in some way related. Nosema 

 disease was not found, however, in one of the two colonies with 

 amoeba disease in the apiary of the Bee Culture Laboratory, nor in 

 the sample from California. 



