NOSEMA-DISEASE. 23 



in general to those employed and described in the sacbrood studies. 

 It should be stated in addition that no watering place for the bees 

 was provided at the time of these experiments and none with sluggish 

 water was near by. 



The results of an experiment usually can be determined during the 

 second week following the inoculation. The diagnosis is made as 

 described later in the present paper (p. 48). Usually one examina- 

 tion of 10 bees is sufficient for the determination of results. It is 

 advisable sometimes, however, to make others. 



As a, rule experimental colonies inoculated during the summer 

 recover from the infection and can be used again. The period which 

 must elapse, however, before they can be used for a second experiment 

 varies. An examination of the field bees should show no infection 

 among them or only an occasional infected bee before another inocu- 

 lation is made. A colony used in the laboratory is good for one 

 inoculation only if by it Nosema-disease is produced. Should the 

 results be negative following an inoculation, however, the colony may 

 be used in a subsequent experiment. 



It is not necessary to disinfect a hive which has housed a Nosema- 

 infected colony. The experimental colony may or may not have a 

 queen. If one is present no concern need be felt in regard to whether 

 or not she is infected. No fear need be entertained that drones from 

 infected colonies in the apiary will transmit the infection to the 

 experimental colony. 



EFFECT OF NOSEMA INFECTION ON THE COLONY AND ON THE APIARY. 



To determine the effect which Nosema infection in a colony pro- 

 duces on the colony, and on the apiary of which the colony is a part, 

 is a problem in the study of Nosema disease which is of vital interest 

 to the beekeeper. Some observations have been made bearing 

 dii'ectly upon this point. 



EXPERIMENT NO. 1. 



On September 13, 14, 15, and 18 ten colonies were fed a sirup 

 suspension of the crushed intestines of Nosema-infected bees. These 

 colonies (Table II, Nos. 6a, 12, 25, 35, 41, 55, 65, 66, 67, and 70) were 

 in the apiary mentioned on page 13. Those selected for inoculation 

 were not especially strong, the bees being easily accommodated on 

 six or seven brood frames and being about an average for the apiary. 

 Examinations show that about 10 per cent of the pollen-carrying 

 bees of these colonies were Nosema infected at the time of the 

 inoculation. The 32 uninoculated colonies in the apiary served as 

 checks. 



It will be seen from Table II that after inoculation 50 to 100 per 

 cent of the pollen-carrying bees in the inoculated colonies were 

 Nosema infected. Out of the 100 bees examined from these colonies 



