30 CIRCULAR 3 9 2, U. S. DEPARTMENT OF AGRICULTURE 



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 a drop of blood oozes out that can be 

 examined. 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 clays the body, legs, wings, and antennae usually fall 

 apart at the joints when the bees are handled (fig. 19). 



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, 

 Vahlkampfia (M alpighamoeba) mettifica, 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. 



IMPORTANCE 



Very little is known about the disease, but the infected bees are 

 undoubtedly injured. Its economic importance is probably negligi- 

 ble, although this point has not been definitely determined. 



SYMPTOMS 



The disease cannot be recognized in the apiary by any symptoms. 

 Dead bees that contain the parasites do not differ in appearance from 

 bees dead of other causes. Field bees that appear entirely normal 

 may also be infected. The parasites are found, often in large num- 

 bers, in the excretory organs (malpighian tubules) of the bees. 



